Post on 11-Feb-2017
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Geosynthetics
CASE STUDIESSafety and Reliability with ACE Solutions
ACE Geosynthetics, established in 1996, is a leading geosynthetics manufacturer and solution provider headquartered in Taiwan. We develop, manufacture and supply a wide range of reliable geosynthetic products that are approved and certified by CE, NTPEP. We also customize products to meet clients’ various needs. In our company are more than 40 experts in civil, geotechnical, marine, hydraulic and environmental engineering who provides professional technical service and cost-effective solutions that help clients realize projects with success and efficiency.
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What We OfferTechnical ConsultationWe work closely with clients and provide advice in every stage throughout the entire process, including selecting optimal products, proposing solutions and giving advice on material installation.
Construction AssistanceWe offer on-site technical support on request during construction to ensure proper installation of products and structural stability.
Structure design and analysisOur experienced engineers design and conduct analysis with professional engineering software such as MSEW, ReSSA, Reslope, Stedwin and GeoCoPS, and provide drawings or advice to help clients install materials properly.
Product customizationWe customize products for clients. Many of our products including ACEGrid®, ACETex®, ACETube®, ACEFormer™ and ACEBag™ can be made according to individual specifications to fulfill particular requirements.
Our experience and achievements:● Reinforced walls and slopes
● Soil stabilization
● Ground stabilization
● Pavement reinforcement
● Erosion control
● Sewage and sludge dewatering
● Shoreline remediation
● River / wetland remediation
● Coastal protection
● Harbor dredging
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MarineStructures Beach Nourishment with
ACETube in the UAE®
The BackgroundIn 2007, the fierce tropical cyclone, Gonu, hit Al-Fujairah, UAE, wreaking havoc on the coastline of the emirate. The cyclone’s attack caused severe erosion
and washed away kilometers of the beach. Though the drifting sand could supplement the loss of the beach, it was unlikely for the beach to fully recover in a
short time. This situation might well get worse when other cyclones came.
The ProblemThe project owner, Le Meridien Beach Resort, located right on the beach was under the threat of
the washout and sand loss which not only jeopardized its very existence, but also kept tourists
from visiting this place. Therefore, the resort owner tried to build two breakwaters with
riprap to protect the beach, but without a solid foundation, the breakwaters sunk and
vanished in the sea because of continuous wave impact and cyclone attacks.
The SolutionThe ACE engineering team proposed using ACETube
® as the main
components to build a U-shaped submerged breakwater with its
opening towards the beach. The whole structure formed a zone
of 228m × 225m underwater to reduce wave energy and nourish
the beach in the meantime.
The Contribution With the filling of in-situ sand, the project cost was brought down
and the construction time was substantially shortened.
Furthermore, the flexibility and permeability of the geotextiles
allowed ACETube®
to adapt itself under the influence of the waves
and go with the currents. Such qualities greatly increased the service
life and the effectiveness of the structure.
200m225m
228m
A
A1
Straps for Handler loop
Scour ApronACETube®
SECTION A-A1N.T.S.
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Beach Nourishment with ACETube in the UAE
With the filling of in-situ sand, the project cost was brought down
and the construction time was substantially shortened.
Furthermore, the flexibility and permeability of the geotextiles
allowed ACETube®
to adapt itself under the influence of the waves
and go with the currents. Such qualities greatly increased the service
life and the effectiveness of the structure.
MarineStructures
ACETube - The Project of an L-Shaped, Sand-Containing Breakwater in the UAE
The BackgroundThis project was at a coast in Ras Al Khaimah, UAE, where there was a groin for the protection of the
navigation channel. The local authority planned to build a fishing port right there where the groin was
and decided to make use of it as a part of the port.
The Problem An L-shaped breakwater of about 700m long was designed to be attached to the groin to make a port.
The newly-built breakwater of 147m would reach from the coast with a right-angular turn to the
northeast and another 524m to be connected with the groin. The whole structure should be 9m high,
2.5m of it under water and 6.5m above the sea level on account of the tidal range being 3m.
Cost-effectiveness, fast construction, and optimal safety were the requirements for this particular
project. However, most breakwaters in the UAE are built with rubble which is costly. Other materials,
such as concrete boxes (caisson), concrete blocks are also expensive. Therefore, the local authority
wished to look for a more economical option for the project.
The SolutionAfter a thorough assessment, ACETube
® was chosen for the proposed breakwater. ACETube
® filled
with sand was used to be the core of the breakwater.
Externally, ACETube®
was covered with an under-layer of aggregates and further protected by a layer
of armor rocks. The final look was similar to a rubble-mound type breakwater.
The ContributionThe use of ACETube
® for breakwater construction significantly reduced the cost and minimized
environmental disturbance. The result turned out to be better than expected. The project even won
2013 International Achievement Award from IFAI for its outstanding performance.
®
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MarineStructures ACETube for Beach
Erosion Problem at Tabasco, Mexico
®
Circumference=7.8m ± 10cmCircumference Strength=Geotextile Tensile Strength of CD
Anchor TubeCircumference=1.4m ± 10cm
Length of Scour Apron=2.5m
Oil Pipe Φ=0.9m
1.8m
0.3m(min)0.3m(min)
Sea Bottom
ACETube®ACETube®
Location : Paraiso, Tabasco, Mexico Application : Coastal Protection; Facility SupportProduct : ACETube® of 7.4m in Circumference
The Solution To deal with the said situation, ACETube
® was used as the
main material. Filled with in-situ sand, ACETube®
was put
underneath the pipelines to support them and was installed in
the sea along the coastline of 1.9km as a submerged
breakwater to reduce the wave energy and, therefore, nourish
the beach. Thanks to ACETube®
’s flexibility and adaptiveness
in the marine environment, it gave the pipelines a complete
support and also showed good quality acting as a breakwater
without being damaged by the wave impact. The result of beach
nourishment came out to be just as expected as the beach
evolution surveys indicated.
The ProblemDos Bocas PEMEX marine facilities suffered progressive beach erosion which resulted
in the loss of the sand foundation under the pipelines that lay within the surf zone.
Such problem jeopardized oil conduction and infrastructure’s integrity and
increased the potential risk of pipeline failures which would have catastrophic
economic and environmental consequences because the oil production
and conveyance in the country highly depended on these pipes.
The ContributionACEContainer™ delivers high performance and achieves rapid and
effective solution for dredging constructions when compared to those of
traditional techniques. It is helpful for the improvement and maintenance of
ports, harbors and waterways as well as to avoid environmental pollutions
during disposal. Moreover, after ACEContainer™ is laid down on the
seabed, it can be also adopted as the core of marine structure underwater
as breakwater or shoreline protection.
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Dredged Materials Disposal, Wan Chai Development Phase II Project, Victoria Harbor, Hong Kong
The Solution and Innovation
MarineStructures
To deal with the said situation, ACETube®
was used as the
main material. Filled with in-situ sand, ACETube®
was put
underneath the pipelines to support them and was installed in
the sea along the coastline of 1.9km as a submerged
breakwater to reduce the wave energy and, therefore, nourish
the beach. Thanks to ACETube®
’s flexibility and adaptiveness
in the marine environment, it gave the pipelines a complete
support and also showed good quality acting as a breakwater
without being damaged by the wave impact. The result of beach
nourishment came out to be just as expected as the beach
evolution surveys indicated.
Dos Bocas PEMEX marine facilities suffered progressive beach erosion which resulted
in the loss of the sand foundation under the pipelines that lay within the surf zone.
Such problem jeopardized oil conduction and infrastructure’s integrity and
increased the potential risk of pipeline failures which would have catastrophic
economic and environmental consequences because the oil production
and conveyance in the country highly depended on these pipes.
Victoria Harbor is a natural landform harbor situated between Hong Kong Island and Kowloon in Hong Kong. About 220,000 ships
visit the harbor each year averagely, including both oceangoing vessels and river vessels, for both goods and passengers. The
maintenance of normal operation of shipping determines the success of the service. One of the major managing difficulties for port
authority will be the clean-up and disposal of sediments originated from oil mixed settlement of suspended solids and fluvial
sediments from upstream rivers. Environmental concerns have been expressed about the disposal of these dredged
sludge materials, in terms of water quality and loss of natural habitat.
The Problem
To execute the dredging and disposal of the sludge materials, the designer adopted ACEContainer™
for the Wan Chai Development Phase II project for Victoria Harbor. ACEContainer™ is suitable for
environmental needs and it has been widely used for marine and hydraulic constructions as
maintenance dredged material containment for further treatment and disposal. For this
particular project, ACEContainer™ has a custom made dimension of 28m in circumference
and 12m in length with a filling capacity up to 300m³. ACEContainer™ technique took
place on a split bottom hopper barge and the sludge was filled into the container using
clamshell bucket. Once the ACEContainer™ was filled, its openings were sewn shut
and reinforced with rope ties. The barge moved to the designated location, the bottom
opened and dropped the ACEContainer™, which settled to the bottom of the sea.
ACEContainer™ has been designed to withstand the hydraulic impact in the marine
environment with time. Monitoring after the construction has observed no damage
and leakage for the installed ACEContainer™. Use of ACEContainer™ to hold the
dredged materials and drop it into the sea has shown successful to avoid the
spreading of suspended solids in the water and thus it is indeed beneficial for the
treatment of dredged materials.
RiverbankProtection
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Bridge Piers Protection, Zhongsha Bridge, National Freeway No. 1 Taichung, Taiwan, ROC
The ContributionThe construction was completed in 2012. Since then, regular maintenance has been conducting to ensure the performance of the structure and therefore to secure the safety of local
residents and the commuters on the bridge. Both ACETube®
and ACEFormer™ are products of low energy consumption and low carbon emissions. In comparison with traditional
concrete structural system, uses of ACE materials herein not only present eco-friendly sustainability, but also save the cost of expensive concrete material. In addition, the flexibility of
these materials makes them adaptable to different kinds of landforms and site conditions, not only making construction much easier, but also helping the structures to accommodate to
the environment. Even typhoons that bring disastrous floods were unable to cause any damage to them. The completed structures are beneficial for erosion prevention. The scouring of
the pier foundations is now under control. The fertile newly-formed land even luxuriantly grows vegetation, making the site totally integrate into the surroundings.
The SolutionThe BackgroundZhongsha Bridge, a 2,345m-long, traditional pre-stressed concrete structure, located on
the Zhuoshui River in Central Taiwan between Changhua and Yunlin Counties. It had been
the longest bridge in Taiwan when it was built in 1978. As the important link of north and
south, the accomplishment of the bridge finalized the construction of the National Freeway
No.1, the arterial which connects all the major cities on the west coast of Taiwan.
The river at the bridge has been facing continuous impact of fluvial processes. After its
service of several decades, recently, because of long-term persistent severe scouring,
some bridge pier foundations and their surrounding areas had shown extremely unstable
and required an immediate remediation. Considering the importance of the bridge, the
design and construction of the remediation were strictly required to follow the highest level
of engineering performances. The remediation consisted of riverbank revetment
rehabilitation, repair and reinforcement of submerged-weir groundsill and aprons
protection. The remediation was mainly to secure the bridge stability and ensure the
necessary traffic safety. In addition, flooding always submerged the farmland adjacent to
the river and put the residents and their property in great danger. The mitigation project
also provided necessary protection for the farmland in that area against damage.
In this project, geotextile tubes, ACETube®
and geotextile mattresses, ACEFormer™ were
adopted to solve the abovementioned problem. The protection was designed to be 5.6m high
with four layers of ACETube®
. After each layer of ACETube®
was filled with in-situ sand,
local fill was then placed and leveled on the top to make an even surface for the installation
of the following layer. Such procedure was repeated until the four layers were finished.
At the end of construction, the four-layer structure was covered with ACEFormer™ filled with
concrete, which not only increased the impact resistance of the structure and kept
ACETube®
from external damages caused by driftwood or debris coming down the river, but
also enhanced the stability of the pier foundations and dikes. Furthermore, the mattresses
used here were pervious which allowed the excess water in the structure to discharge into
the river, thus making the structure more stable. The uneven surface of ACEFormer™ also
helped reduce flow velocity and slowed down the erosion process.
ACETube®
and ACEFormer™ proved to be a better solution also because of their flexibility,
which allowed them to easily adjust to various landforms in the process of construction. In
this case, such property was especially advantageous when the construction was located at
river curves. Both materials showed higher applicability than other rigid structures under
such conditions. As a result, the combination of these two materials provided more reliable
protection to the pier foundations and the dikes and essentially improved the structural safety
of the bridge.
Revetment Protection, Anliang Harbor Canal Taichung, Taiwan, ROC
Anliang harbor canal, one of the most important waterways in Taichung area, is responsible to discharge the
collected water from the upstream basin of Grand Metropolitan Taichung. However, due to the accumulation of
silt and trashes and the randomly overgrown weeds, the volume of the waterway had significantly reduced.
Therefore, the discharge capacity of flooding had decreased, led to the scouring effect more and more severe
with time. Such malfunction not only jeopardized the stability of the canal, but also caused local residents
vulnerable to flooding risks. The poor canal condition must be improved in a timely manner.
The Background
RiverbankProtection
ACE Revetment Composite System – A Novel Remediation Solution for Waterfront Environment
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Considering the importance of the canal, Taichung City Government called for a
remediation project, including dredging, widening, and remodeling of the canal.
The purpose was not only to resume the flooding protection capability but also
to reinstate the canal as an eco-friendly environment for residents and visitors.
Based on the client's objectives, the designer developed the scheme of the
project: safety, durability, aesthetic, and sustainability.
The first step of the construction was to stabilize the base of the canal by
installing pile-supported reinforced concrete revetment for areas below the
water level. Then, reinforced earth slope (RES) with ACEGrid®
was placed
as revetment in the upper portion of the canal. The RES also functioned as
the retaining structure for the service road along the canal. It was constructed
with geogrid wrap-around facing with an inclined ratio of 1:2 (H:V). Stacked
soil-filled ACEBag™ was used for slope face protection. They were
hydro-seeded and the vegetation has been displayed pleasant greenery with
time. ACEGrid®
and ACEBag™ are products of low energy consumption and low
carbon emissions. They were integrated with local compacted natural soils and
finally built together as a totally sustainable structure.
The construction took about four months to complete in the summer of 2011. Since
then, the revetment has been through several attacks of strong typhoons and by far still
remains in stable condition. The durable service condition together with a variety of
valuable species and the attractive waterfront scenery on the site has proved ACE
revetment composite system totally meets the demands of the project objectives: safety,
durability, aesthetic, and sustainability.
In this project, geotextile tubes, ACETube®
and geotextile mattresses, ACEFormer™ were
adopted to solve the abovementioned problem. The protection was designed to be 5.6m high
with four layers of ACETube®
. After each layer of ACETube®
was filled with in-situ sand,
local fill was then placed and leveled on the top to make an even surface for the installation
of the following layer. Such procedure was repeated until the four layers were finished.
At the end of construction, the four-layer structure was covered with ACEFormer™ filled with
concrete, which not only increased the impact resistance of the structure and kept
ACETube®
from external damages caused by driftwood or debris coming down the river, but
also enhanced the stability of the pier foundations and dikes. Furthermore, the mattresses
used here were pervious which allowed the excess water in the structure to discharge into
the river, thus making the structure more stable. The uneven surface of ACEFormer™ also
helped reduce flow velocity and slowed down the erosion process.
ACETube®
and ACEFormer™ proved to be a better solution also because of their flexibility,
which allowed them to easily adjust to various landforms in the process of construction. In
this case, such property was especially advantageous when the construction was located at
river curves. Both materials showed higher applicability than other rigid structures under
such conditions. As a result, the combination of these two materials provided more reliable
protection to the pier foundations and the dikes and essentially improved the structural safety
of the bridge.
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RiverbankProtection
Project Outline"Niaosong Canal Widening and Improvement Project" was part of the
program of “Flooding Mitigation for Flood Prone Area in Grand Kaohsiung
Metropolitan Area”
By widening, dredging, and remodeling of the canal, the objectives of the
project were to:
• Resume the discharge capacity of flood control
• Reduce the risk of flooding
• Ensure the safety of local residents and their properties
• Promote favorable land appreciation
In addition, the construction also entitled the canal to become an eco-friendly
environment and a water-accessible area.
ACEFormer
Apron
GuardrailWalking Path
TM
Design ConceptPursuing the objectives of the project, the designer came up with a good
idea of using ACE Revetment Composite System to meet all the
requirements in one solution. To overcome the scouring, reinforced
concrete (RC) revetment was used for the area below the water level. The
revetment was then backfilled with engineered fill, sloped upward and
backward to the pavement grade. To prevent the erosion of surface run-off
and to minimize the possible harsh destruction due to overflow or flooding,
geoformer (ACEFormer™) was placed on the backfilled surface. Different
from traditional concrete structure, ACEFormer™ not only provides a
durable surface for scouring resistance, but also offers spaces for
vegetation to grow.
Since 2010, the completion of the project, the initial palish gray surface of
the ACEFormer™ has been changing to richly fresh green and a variety of
local species have observed on site. Although the site has experienced
several challenges of strong typhoons and torrential rainfalls, the canal
stays stable and the flooding damages have ceased completely. The
successful experience of this project demonstrated that ACE Revetment
Composite System can be beneficial for a site similar to this case.
Riverbank Protection, Niaosong Canal, Kaohsiung, Taiwan, ROC
EnvironmentalProtection
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Industrial Sludge Treatment Capacity Improvement with ACETube
The ContributionOne of the advantages of the new technology - ACETube
® is installation is possible in a
job-site with the limited area. Besides, initial dewatering efficiency is excellent. Carbon
emissions of ACETube®
cause less harm to the environment. Efficient dewatering
means taking less space in the job-site. After finishing safety analysis, the contractor
made sure that there is no problem about it and continued using ACETube®
for 2.5
months. What is more important - ACETube®
not only saved time, but also made more
space for the buffer pool.
The SolutionWhile dewatering process with ACETube
®, there are four stages: pumping, dewatering,
solidification and disposal. In the first stage a dredging boat with capacity 230m³/hr was
used to pump sludge into ACETube®
. In order to promote dewatering efficiency,
flocculant or polymer were pumped into sludge. Before that, jar test/ cone test should
be done for the best dosage. Polymer dosing system could mix polymer with sludge for
keeping them well-mixed and dewatering efficiency. To meet requirement of the project,
filling ports and the tube size were customized. Its circumference is 11.5m; length –
45m; tube capacity is about 500m³. 30 pcs of ACETube®
are used in this project.
The ProblemThe contractor used the sludge buffer pool with depth 3m. The main function is storage
of sludge for dewatering treatment. However, if sludge volume is huge and there is no
more space to build new buffer pools, it will cause full load to the treatment plant due to
low dewatering efficiency and accumulated sludge volume. Now there is a new
technology method - ACETube®
for sludge dewatering. ACETube®
has the following
advantages: ACETube®
can be installed properly according to practical conditions of the
job site; fast dewatering process can promote treatment efficiency and capacity of the
buffer pool.
The BackgroundTraditional wastewater treatment plants have two methods for sludge dewatering.
One is natural exposure in sludge drying beds; the other is to use dewatering
machines. Dewatering by means of drying beds entirely takes advantage of sunlight.
The shortcoming is inefficiency. Besides, treatment volume also depends upon the
area of drying beds. Speaking of dewatering machines, such as belt press filter, it is
an industrial machine, used for solid/liquid separation processes, particularly the
dewatering of sludge. The machine needs not only electricity, but also regular
maintenance. It means operation costs are required, too. Moreover, carbon emission
is another issue. In fact it is not beneficial to costs and environment.
®
Erosion Control
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Treatment and Erosion Protection, Upper Slope of Tunnel Portal Taichung, Taiwan, ROC
The ProblemIn July 2006, a torrential rainfall attacked the site and totally saturated the decomposed slope surface. A typical shallow plane failure was then triggered
and caused the surface to slide off the bedrock. The movement further loosened the cementation of the weathered sandstone and thus seriously
jeopardized the traffic safety of the portal area. The managing authority called for an immediate rehabilitation not only to stabilize the upper slope but to
resurface the portal area for scenic improvement as well.
The Solution and Innovation3D diamond-shaped high-tensile steel wire mesh was first secured onto
the bare slope using grouted rock nails. A base layer consisted of mixed
seeds, fertilizer, and water-bearing material was hydro-sprayed on top of
the wire mesh networks. High tensile strength ACEMat™ R, a 3D cellular
confinement material, was then fixed together with the steel wire mesh
using rock nails.
The ContributionThe composite slope protection system not only secures the weathered
sandstone, it gives a fresh green looking at the portal area as well.
ACEMat™ R offers spaces for vegetation to grow. It is also attractive for
a variety of local species to stay. Although the site has experienced
several challenges of strong typhoons and torrential rainfalls, it remains
stable with richly grows vegetation. The design scheme has proved such
composite slope protection system with ACEMat™ R totally meets the
demands of an eco-friendly environment with sound stability.
The BackgroundThis project took place at the portal area of tunnel No.9 of
an abandoned railway (currently remodeled as a scenic
bike path) in Taichung. The surface of the upper slope at
the portal area has been covered by a layer of completely
weathered and fractured sandstone with a thickness of 1 to
2m. According to the environmental geological studies
given by the Central Geological Survey, the site has been
classified as debris sliding zone. It appeared to be very
unstable and risky upon any disturbance.
Erosion Control
Slope Rehabilitation, Renai Access RoadNantou Taiwan, ROC
Soil Bag
Vegetation
New Jersey Barrier
Drainage Board
Drainage Boardand Aggregate
RC Plate
Steel Pile
0.3
1
PC PavementPC Pavement
Original Slope
Anchoring System
Fixing System
Anchoring NailGeomat WithinVegetation Substrate
The BackgroundRenai Township is a mountain indigenous village in Nantou
County, Taiwan. It is famous for its aboriginal culture
products and beautiful nature scenery. The site is located in
Renai Township. The slope disrupted during an attack of
torrential rainfall due to its poor geological and hydrological
conditions. The slope was damaged seriously with a
collapsed depth over 30m and led to a total loss of the road
structures and thereafter the interruption for the local traffic.
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The Solution
The ContributionACEMat™ R offers sufficient spaces for vegetation to grow. It is
also attractive for a variety of local species to stay. The
eco-system not only provided stabilization for the fractured slope
but also improved the appearance of the site. Since the
completion of the project, the composite system has been
through a number of typhoons and severe rainfalls, however, the
installed system stays functional and the slope presents
sufficient stability. The strategy of using ACE green system to
substitute traditional gray structures has awarded numerous
compliments because of the success of this project.
The designer introduced a composite engineering system for the rehabilitation. First, a reinforced concrete mat foundation with steel H toe piles were installed as
base support. Then, a mechanics stabilized earth wall (MSEW), 5m high and 6m wide, was built to serve as the embankment for the access road. The MSEW was
constructed in compacted layers which consisted of in-situ soils and the ACEGrid®
. They were piled up with 0.5m increments until reaching the design height.
Stacked soil-filled ACEBag™ with geogrid wrap-around facing was used for face protection. A step back inclined ratio of 1:0.3 (V:H) was maintained to allow for the
most possible width of the access road. ACE drainage board and geotextile (ACETex®
) were arranged within the MSEW as intercept system for prompt seepage
dissipation. For damaged slope below the MSEW, traditional solution such as shotcrete or cross concrete structural bars are commonly applied. They are fast,
strong and effective to protect a weathered rock slope. However, their awkward appearance and impermeable surface ruled out their possibilities for this project.
The designer selected an eco-friendly and green system for the downslope protection. 3D diamond-shaped high-tensile steel wire mesh was first secured onto the
bare slope using grouted rock nails. A base layer consisted of mixed seeds, fertilizer, and water-bearing material was hydro-sprayed on top of the wire mesh
networks. Finally, high tensile strength ACEMat™ R, a 3D cellular confinement material, was then fixed together with the steel wire mesh using rock nails. In
addition, longitudinal and horizontal trench systems also were installed to facilitate the drainage of surface run off.
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The ContributionThe construction of the Pinglin forest park provides an environment which
can not only conserve water, adjust temperature, provide a biological
habitats but also maintain the current landscape. The use of the green
materials ACEMat™ R avoid the visual oppressive of concrete and form a
multifunctional ecologically sustainable green park to adjust the temperature
in the near region and effectively decrease the air pollution.
Taichung Pinglin forest park covering about 11.7 hectares, is located
opposite the Taichung Armed Forces General Hospital, near to the National
Chin-Yi University of Technology. This park sits on the land originally
reserved for military use. In recent years, due to the decrease of the military,
reducing the demand of land, and the governments urban plan policy, the
government intended to reconstruct this area as a multifunction ecological
park providing recreational space, a scenic environment and a
water-detention basin.
The Background
The Problem In this case, in order to achieve the government’s policy objectives and
improve the greening rate, the owner intends to plan a forest area exceeding
3.7 hectares, plus a water-retention basin of 32,000m². It not only provides
the function as a detention basin, water collection during the flood but also
offers a pleasant forested place for the residents to enjoy their time in
normal period, moreover promotes the development of this area.
In this case, the area start up to construct the green park and ecological
water-retention basin, in order to make a green landscape, using the
rectangular pyramidal geomat, ACEMat™ R to do the green work. The area
covered by the ACEMat™ R is about 8,000m². ACEMat™ R manufactured
by polypropylene yarns, with the three-dimensional structure can closely
integrated with the soil which supporting vegetation. Furthermore, thanks to
the increase of the surface roughness, surface soil eroded by the rainfall can
be avoided. ACEMat™ R can protect slope and also prevent the erosion rill
formed naturally to expand. In addition, ACEMat™ R with the flexibility
characteristic can be adapted to the local terrain condition and be installed
easily.
The Solution
One Ecological Landscape Park with ACEMat™ R – Taichung Pinglin Forest Park
Retaining Walls
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Slope Rehabilitation, Xihu Service Area, National Freeway No. 3Miaoli, Taiwan, ROC
Retaining Walls
The ChallengesThe highway authority required that the rehabilitation should be a sustainable
solution to fully conform to an aesthetic and eco-friendly environment. In
addition, the owner also required the construction to be completed within a
limited schedule to minimize the traffic impact.
The BackgroundNational Freeway No. 3, one of the most important north-south
arteries in Taiwan, is famous for the scenery along its line. Because
of the enormous demands of transportation, any slope instability that
might endanger the traffic flow must be treated immediately. An 8m
high slope was found to slip near the entrance of Xihu service area of
the highway due to the results of a torrential rainfall. The deterioration
was consequently jeopardizing the safety of the highway with time.
ACE Innovative ApplicationTo meet all the requirements of the project, a wrap-around reinforced earth
structure (RES) containing ACEGrid®
, soil bags, local soil, and drainage materials
were chosen to restore the slope. There are five reasons for adopting this solution:
(1) excellent quality and durability of ACEGrid®
ensure the stability of the RES; (2)
a well-designed integrated vertical and horizontal drainage system; (3) fast
construction significantly reduces the traffic impact; (4) a flexible wrap-around
facing system perfectly fits in-situ surrounding changing contours and also easily
maintains a slope of 1:1.5-1:2 (H:V) identical to the original design; and (5) the
porous surface structure of the RES provides a friendly environment for the
development of local vegetation and an ecological system. The results proved the
ACE system to be the novel solution to totally meet the demands of the site.
The Conventional SolutionTo build a cast-in-place reinforced concrete (RC) frame in-filled with
seeded soil bags. Such design is costly and the RC frame involves
much more labor and materials for construction. It is also not a
solution which favors sustainability. The completed surface also
requires a relative longer time to develop sufficient vegetation to
cover the RC frame.
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Our client planned to develop a residential housing complex in a
mountainous area where rugged terrain is typical. Substantial levelling off
the site was mandatory because of engineering safety. For conventional
solution, multiple tiered retaining walls have to be built to accommodate
different housing arrangements. However, such design not only introduces
enormous amount of cut and fill earth construction but also makes
foundations vulnerable to differential settlement. Cantilever retaining walls
are costly and susceptible to seismic damage. Reinforced concrete
structures also require longer time to complete.
The Background ACEGrid® Fits Challenging ConditionsBy exploring the advantages of ACEGrid
® mechanically stabilized earth
(MSE) wall, the developer finally adopted it as the solution for the site.
The ACEGrid®
MSE wall allowed engineers to integrate cut, fill, and
retaining structure into one step which made the site preparation much
straightforward. Compacted fill reinforced with ACEGrid®
satisfied both
static and dynamic loads, and therefore becoming a perfect
seismic-stable structure. Differential settlement also was not likely for
such an engineered earth structure. The total length of the MSE walls
was more than 300m and the height were varying from 7 to 12m to fit the
terrain of the site. For aesthetic requirement, the designer specifically
selected modular concrete blocks as the face of the MSE wall to match
well with the appearance of the surrounding housing complex. Although
the site condition was difficult, the final completed ACEGrid®
MSE wall
presented excellent result better than expected. The system has been
proved totally meets the demands of the site and worthy of being
considered as a model for future similar development.
ACEG
rid®
Segmental Block Face
Drainage Aggregate
Concrete Face
Steel Fence
ACEGrid Delivers Novel Solution for Difficult Site PreparationChilpancingo, Mexico
®
Retaining Walls
ACEGrid® Fits Challenging Conditions
In September 21 1999, a devastating earthquake, dubbed the "Quake of the Century" by local media, struck the site and caused severe damage to the slope and its drainage system. Large amounts of gushing water subsequent to several heavy rainfalls led to severe surface erosion and further destruction of the slope. Although the managing authority conducted some mitigation measures, the sliding had never been accurately treated and condition was worsening with time. The safety of the industrial complex adjacent to the sliding zone thus is critically jeopardized, and the slope must be rehabilitated immediately.
The ChallengesThe height of the collapsed slope was about 30m and the averaged
inclination was over 70°. The geological formation at the site was red
clayey silt intermixed with gravel. This is a typical difficult formation in
Taiwan as it is very sensitive to the variation of its water content. The
rehabilitation should not only stabilize the slope and protect it from future
seismic damage, but should also prevent surface run-off and groundwater
seepage softening the silty gravelly formation. The managing authority
required that the restoration should be completed with a sustainable
solution within a limited schedule. The construction should try to utilize all
the collapsed rubble and the site should be as green as possible to match
well with the surrounding environment.
ACE Innovative ApplicationConsidering safety, durability, and sustainability, the designer finally adopted ACE reinforced earth slope
(RES) composite system for the rehabilitation. Based on the stability analysis, secant piles and toe berm,
reinforced concrete structural members with stronger stiffness, were installed at the toe to provide sufficient
base support. Then, 11 tiers of reinforced earth slope using ACEGrid® and the on-site collapsed rubble were
placed in sequences up to the crest. The RES was constructed with geogrid wrap-around facing with each tier
at a height of 3m and an inclined ratio of 1:2(H:V). ACE drainage board, pipe, and geotextile (ACETex®) were
arranged elaborately as intercept system in the RES for prompt seepage dissipation. Longitudinal and
horizontal trench systems were also installed to facilitate the drainage of surface run-off. Soil-filled and
hydro-seeded ACEBag™ was stacked for slope face protection. Since installation, the project has visually
integrated into the environment through the growing of vegetation. The aesthetic appearance, together with a
variety of local species observed on site, has demonstrated the eco-friendly capabilities of the ACE system. In
addition, the completed ACE reinforced earth slope has remained in good condition through the deadly
Typhoon Morakot in 2009. It is indeed a safe, durable, aesthetic, and sustainable solution for similar projects.
Riverbank Slope Rehabilitation, Proximity to National Freeway No. 4, East Sta.0+8k, Taichung, Taiwan, ROC
Drainage PipeExisting Structure
ACEG
rid®
ACETex®
ApronBarrageConcrete Dam
Concrete Pile
Basin
The Background
The Conventional SolutionSoil nailing together with shotcrete stabilization can usually be used for fast treatment of a steep slope such as this project. However, its appearance is totally not compatible with the local environment. Its impermeable surface will also create difficulties with the efficient draining of abounding groundwater, therefore increasing vulnerability to seepage damage. The disposal of piled rubble on site also will be extremely difficult for the contractor.
16
Retaining Walls
The ContributionThe project was effectively completed within the limited budget and
schedule. In-situ soil was well compacted and wrapped in the structure,
contributing to the sound resistance of RES. Vegetation growth to date
enhances the performance of erosion control and the natural
appearance of the site. ACE products consume low amounts of energy
and produce low carbon emissions. They were integrated with local
compacted natural soils and finally built together as a completely
sustainable structure.
The Solution and InnovationSince the in-situ gravelly clayey sand could be utilized to cut down construction
cost, reinforced earth slope (RES) with ACEGrid®
was adopted for this project.
It was 10m in height and 34m in length, supporting by a reinforced concrete
mat foundation with steel H piles at the toe. The RES was constructed in two
tiers with geogrid wrap-around facing setback with an inclined ratio of 1:2(H:V).
Stacked soil-filled and hydro-seeded ACEBag™ was used for slope face
protection and visual integration with the surrounding environment. For
damaged slope below RES, high strength geomat, extending 50m downward
was installed and vegetated. It was designed for erosion protection and for
scenic improvement at the site. Lastly, intercept trenches and New Jersey
guard rails were installed for surface run off drainage and traffic safety.
This project was to rehabilitate a downslope failure for a section of Route 119
in Miaoli County. The engineering properties of the slope were poor, and a
torrential rainfall subsequently triggered the landslide. The slope was badly
damaged, leading to the loss of partial subgrade. One lane had to be closed,
and local traffic was severely impacted.
The Background The ChallengesThe site proximity was not accessible for construction and the traffic also
must be resumed in a safe and timely manner. Moreover, the managing
authority had financial constraints and was unable to provide complete
financial support for the rehabilitation project. Therefore, the construction
needed to be completed within a tight schedule and limited budget. The
construction needed to not only prevent such disaster from happening
again, but also provide sound quality to guarantee road safety.
17
Slope Rehabilitation, Route 119, Miaoli, Taiwan, ROC
Roadway Construction
Roadway Construction
18
The BackgroundThis project is located in Jempol, Negeri Sembilan in Malaysia. Highway N17 originally had only one lane. To improve the quality and convenience for the
regional traffic, County Government called for a highway widening and intersections improvement project for Jalan Dangi, Kepas and Bahau. However, the
soft subsurface and the rainy conditions of the proposed site created difficulties for the proposed construction.
The ContributionSince the completion of the project, the highway has performed well
to date. No instability or settlement has been observed around the
site. ACE ground stabilization system provides a simple, fast, and
cost effective solution for ground reinforcement.
The system has been demonstrated to completely meet the demands
of the site and is worthy of being considered as a model for other
similar projects.
The SolutionTo solve this problem and help construction operate more smoothly, the contractor first
raised the grade to one meter below the design elevation by filling satisfied site material.
Then, ACE ground stabilization system was placed to reinforce the weak subgrade. It
consisted of a layer of ACETex®
and a layer of ACEGrid®
. ACETex®
was designed for
filtration and drainage, and ACEGrid®
, a bi-axial high resistance product, was installed
for bearing capacity improvement. A 45cm thick compacted fill was then placed and a
second layer of ACEGrid®
was installed. Geogrids fully interlocked with soil particles
created an enhanced composite material with higher performance characteristics.
Crushed base course and asphalt concrete surface course was each then placed as
those procedures for traditional pavement construction.
Widening and Intersections Improvement, Highway N17,Jempol, Negeri Sembilan, Malaysia
Roadway Construction
19
ACE Eco-MaterialsGeogrids (ACEGrid
®), Soil Bags (ACEBag™), Geotextiles (ACETex
®)
ACE drainage system (Drainage Board, Drainage Pipe, Drainage Ditch)
The ContributionThe reinforced earth structure with ACE products provides a simple, fast, and cost effective
solution. It can be constructed without topographic constraint and using common equipment
with lesser skilled laborers. The RES here also was built using local collapsed rubbles and
thus greatly reduced the amounts of waste dumps. Because ACE system has shown a sound
performance, the deformation rate observed at the site declined from 0.03mm/month to
0.007mm/month within the first 6 months. The gathered information of instrumentation clearly
indicated that the sliding has been successfully controlled. Based on the site conditions, ACE
solution, a custom made system for this project, has proved to be beneficial for this type of
slope rehabilitation and is worthy of being considered for other similar conditions.
Soil Anchor
ACETex®
ACEG
rid
Gravel Filled
Drainage Pipe
Drainage Pipe
All-Casing Pile
Cantilever Retaining Wall
®
Soil Bag Filled with AggregateSoil Bag
H.W.L
L.W.L
Application of ACE Composite System near Fault Zone, Route 131, Nantou, Taiwan, ROC
Roadway Construction
The BackgroundThis project is located in Route 131 in Nantou County. Based on the investigations of regional geologic
survey, there are several fault zones pass through the site. As a result, the geological conditions are very
poor, and the rock formations are fractured and weak. In 2007, a significant landslide up to 80m wide and
30m deep occurred due to a torrential rainstorm. The existing anchored downslope was severely damaged
with the main structure being pulled out and exposed after the landslide, forming a massive heave at the toe
of the slope.
The Challenges and SolutionThe site is located in the water supply reserve area of Ming-Tan Reservoir. The toe of the slope was
vulnerable to scouring due to water level fluctuation in the reservoir. After careful stability analysis, a
composite protection system was adopted. To meet all the requirements of the project, the rehabilitation
consisted of two stages. In stage I, a pile-supported reinforced concrete (RC) waterfront protection wall was
built for the lower slope below the highest water level. Drilled concrete piles (1.5m in diameter, 20m to 30m
long, 2.5m in space) were used to support the protection wall (8.5m in height). Ground anchors also were
installed to give additional tie-back resistance. The durable RC structure was designed to prevent any
possible instability from scouring. In stage II, a wrap-around reinforced earth structure (RES) containing
ACEGrid®
, ACEBag™, and drainage materials were chosen to restore the slope above the protection wall.
The RES was constructed in 4 sequential tiers up to a final height of 17m using geogrids 8 to 10m long. Each
tier was setback with an averaged inclined ratio of 0.3:1 (H:V). Stacked soil-filled ACEBag™ was used for
slope face protection. It also functioned as the medium of planting as vegetated slope was not only good for
an aesthetic appearance but also for an eco-friendly environment. Interior and surface drainage systems
were also installed properly for the RES to effectively drain the seepage and run-off.
20
Soil Bag
Drainage Ditch
ACEG
rid®
Drainage Pipe
Bag Filled with Aggregate
Micro-Pile
Soil Nail
Durability and SustainabilityIn addition to the engineering issues, sustainability also is a major
concern of the County Government. Through the innovative ACE
composite protection solution, a safe, economic, and eco-friendly system
has been built. The flourish green vegetation on the RES not only has
given the site a natural appearance but also has become a favorable
place for many local species. It appropriately maintains the traffic safety
for the residents and warrants the site to be an eco-friendly environment
as well. Since the completion of the project in 2007, the site has
remained in good condition through several attacks of strong typhoons,
including the deadly Typhoon Morakot in 2009. The successful of the
ACE composite system in this project has proved its values for this type
of applications to ensure the demands of safety, durability, and
sustainability.
Slope Rehabilitation, Route 35, Pingtung, Taiwan, ROC
From July 7 to August 9, 2006, torrential rainfalls continuously attacked Pingtung; a county contains the oldest and the largest national park at the southernmost
part of Taiwan. The accumulated 1,380mm precipitation completely soaked the ground and therefore caused a section of downslope collapsed in Route 35. As a
result, the subgrade was damaged badly and the highway had to be closed for safety. Forensic investigation indicated that the sliding was mainly due to the
enormous surface overflow out of the drainage gutters along the highway.
The Background
The SolutionConsidering cost, efficiency, sustainability, and site conditions, the designer
introduced a composite protection system for the rehabilitation. Firstly, a
reinforced concrete mat foundation with drilled root piles were installed as base
support. Then, the designer contracted representatives of ACE and adopted
ACEGrid®
as the reinforcing material to build a 3-tier reinforced earth slope
(RES) to support the highway. Additional soil nails, tied up securely with geogrid,
were installed to dowel the deep-seated failure plane to ensure stability. RES
was constructed with geogrid wrap-around facing set back with an averaged
inclined ratio of 1:2 (H:V). It was built in layers using the collapsed residues on
site. Fill materials were placed and geogrid installed at a vertical spacing of 50cm
and they were piled up until reaching the final height of 16~18m. Soil-filled and
hydro-seeded ACEBag™ was stacked for slope face protection. They also
functioned as the medium of planting as a vegetated slope not only provides an
aesthetic appearance, but is also an eco-friendly environment. Interior intercept
trenches and horizontal drains were also arranged to prompt the dissipation of
groundwater. Finally, longitudinal and horizontal trench systems were installed to
facilitate the drainage of surface run-off.
Application of ACE Composite System near Fault Zone, Route 131, Nantou, Taiwan, ROC
Roadway Construction
21
Tai-Route 9 is the most important arteries in connecting Pingtung County and Taitung County. It has world-famous natural scenery along the line in southern Taiwan. In August 2013,
Typhoon Kongrey hit the island with heavy rainfall and caused numerous infrastructure damages in these areas. The project reported herein located at Sta. 470k+500 of Tai-Route 9
where its downslope was totally collapsed due to the riverbank breach which was smashed by the rushing flooding of the adjacent Fenggang River. The in-situ drainage system also
insufficient to accommodate the enormous overflow came from the upper land of the site. The highway was completely disrupted and the rehabilitation was immediately necessary to
resume the normal livelihood of residents and minimize the loss of local tourism productions.
The Background
Performance Evaluation
ACE Innovative ApplicationTo meet all the requirements of the project, the rehabilitation consisted of two pars. In part I, a 150m
long, pile-supported reinforced concrete (RC) waterfront protection wall was built for the lower slope
below the highest water level. The piles were designed with a diameter of 1.2m and a minimum length of
10m. A total of 155 piles, each spaced 2m, were installed in two rows with all-casing drilling technology
and seated into the bedrock for at least 2m. The durable RC structure was used to prevent the instability
from river scouring.
In part II, a wrap-around reinforced earth structure (RES) containing ACEGrid®
, ACEBag™, and
drainage materials were chosen to restore the upper slope. The RES was constructed in two stages
using collapsed debris piled on-site. Each stage has a height of about 5m with an averaged inclined
ratio of 1:2 (H:V) so that a sufficient width of the highway can be maintained. Considering the safety and
the cost, stage I applied stronger ACEGrid®
(Type A geogrid) as the reinforcing material for a total area
of 1,326m² for the lower part of the RES. Another 995m² of ACEGrid®
(Type B geogrid) with lesser
strength was used for the upper part of the RES. Each layer of the fill material was installed with a
vertical spacing of 50cm.
To prevent the surface overflow washing and softening the RES, a 2m X 2m approximately, drainage
culvert was installed below pavement to collect all the possible surface run-off and discharged it directly
to the river.
Stacked soil-filled ACEBag™ was used for slope face protection. It also functioned as the medium of
planting as vegetated slope was not only good for an aesthetic appearance but also for an eco-friendly
environment.
The Conventional SolutionTo build a staged cast-in-place retaining wall and then backfilled in layers
with qualified imported materials to the height of the original pavement. Pile
foundations also must be used to support the structure so that it can stand
firmly on the steep slope and provide sufficient protection for river scouring.
Such design was costly and took longer time to complete. The appearance of
concrete structure also was not favorable for the site.
The ChallengesThe depth of the slope was over 20m and the toe was vulnerable by the
attack of the adjacent river. There were tons of rubbles on site because of the
collapsed debris and the highway managing authority required the
rehabilitation should be a sustainable solution. It must use up these materials
as much as possible and also the final completed structure should be
durable, aesthetic, and eco-friendly. In addition, the owner also required the
construction must be completed within a limited schedule.
Slope Rehabilitation, Tai-Route 9 Pingtung, Taiwan, ROC
Roadway Construction
After four months of construction, this project was completed in May 2014.
Since then it has been through a number of typhoons attacks and by far still
remaining in good condition. Although it has always experienced heavy
traffic, no evidence has been observed for deterioration or instability.
Vegetated slope presents natural appearance and provides an aesthetic and
eco-friendly environment for the site. As many other similar projects already
in use, the rehabilitation has been proved successful.
Taiwan is world-famous in its natural scenery but it also has experienced
numerous record-breaking natural disasters. For such a beautiful but
vulnerable environment, man-made structures should be built as much as
possible to satisfy the requirements of durable, aesthetic, sustainable,
eco-friendly, and seismic-resistant. The project reported herein proved
ACEGrid®
RES system to be the novel solution to totally meet the demand of
the country.
Managing authority of Queensland Motorways proposed to upgrade the existing Gateway Bridge River Crossing. The project included the duplication of the
existing Gateway Bridge and the upgrade of 24km of the Gateway Motorway from Miles Platting Road to Nudgee Road. There were virtually three projects in one:
the Gateway Bridge duplication; a 16km motorway upgrade (south) and a new 7km motorway deviation (north). However, many of the constructions sat on the
flood plain area of the Brisbane River which underlain mostly by soft and saturated fluvial deposits. Low bearing capacity and excessive settlement were highly
likely to occur and consequently jeopardize the stability and safety of the constructed facilities.
The Scope
Ground Improvement, Queensland Motorways Gateway Upgrade Project, Brisbane, Queensland, Australia
® High strength geotexile ACETex® High strength geotexile ACETex
Embankment
Wick DrainageWick Drainage
Gravel Working PlatformGravel Working Platform
Nonwoven Geotextile SeparatorNonwoven Geotextile Separator
®®
High strength Geotextile ACETex
The ContributionACETex
® has a unique structure that enhances its function as a filter
fabric. It has both high permeability and the ability to restrict the
movement of most soil particles, while allowing the very fine silts to
flow into and out of the drain. With the use of ACETex®
, the installation
and the performance of PVDs have been greatly improved. The period
of settlement and consolidation were shortened substantially; the
stability and load carrying capacity were improved significantly.
ACETex®
together with PVDs will be beneficial for embankments
constructed on soft ground for roadways, railroad tracks, or runways
which must be functional in an extremely tight schedule.
22
Soft SoilStabilization
To minimize the risks caused by the soft soils, ground improvement was
extremely necessary. The designer adopted prefabricated vertical drains
(PVD) to accelerate the dissipation of excess pore water in soft deposit and
therefore to cause an increase in shear strength and a decrease in
compressibility. The contractor first placed a layer of ACETex®
drainage
blanket and a layer of gravelly platform on the surface of the ground.
ACETex®
provided functions of separation, filtration, and drainage so that the
induced pore water could be easily dissipated without losing of fine particles.
Then, PVDs were installed in square patterns (spaced 1.5m center to center)
to cover all the treatment areas. As a result of this method of accelerating the
consolidation process, bearing failure and excessive settlement can be
virtually eliminated.
The Solution and Innovation
23
ACEGrid®
GA is being increasingly used at asphalt overlay base level
to enhance the overall performance. The asphalt reinforcement with
ACEGrid®
GA has advantage that it can be placed in the asphalt layer
to restrict reflective cracks and ease of installation. In this project, after
milling of the original pavement, it can be installed directly and
overlaying with hot mix asphalt.
After the construction is completed, the performance of reinforced
pavement showed very good condition. No reflective cracking and
pothole are discovered. On the other hand, the depth of ruts is also
decreased and has well serviceability.
The Solution and Contribution
The main road surface had been damaged due to high axle loads or
increased traffic in Colombia, South America. The original pavement
carriageway was showing extensive reflective cracking, which is major
drawback of asphalt pavements. Commonly a paved road becomes a
candidate for maintenance when its surface shows significant cracks
and potholes. Reflective cracking in the pavement surface cause
numerous problem, such as discomfort for the users, lower safety,
added the infiltration water and reduction of bearing capacity.
Therefore, the government would like to choose economical and
long-term performance way to solve the cracks on the pavement.
The Problem
PavementReinforcement
Glassfiber Geogrid─ Main Traffic Road in Colombia, South America
24
11
0.3 0.3
11
0.3 0.3
Silt Fence TrenchReinforced Earth
Embankment
Drainage Ditch1
2
Gas Collection System (Pipe)
Geomembrane
HDPE Drainage Pipe
ACEGrid + ACETex + Soil Bag®®
The capacity of Kaohsiung Class B Waste Landfill has become insufficient due to the increase
of population over the years. Therefore, the managing authority issued an immediate project to
prompt for an expansion for the facility. The construction required to build a new containment
system to accommodate future additional refuse. Because the area of the site was very limited,
the perimeter dike of the containment must be built as steep as possible.
The Problem
Reinforced Earth Dike, Class B Waste Landfill Expansion Project, Kaohsiung, Taiwan, ROC
The Solution and InnovationBased on a careful site evaluation, the in-situ silty sand could be utilized as fill material for
dike construction. The excavation of existing material also led to an increase in the
capacity of the containment. Considering the requirement of service volume, the designer
finalized a reinforced earth structure as the perimeter for the containment. ACEGrid®
was
adopted as the geogrid reinforcement so as to maintain a steep slope of 1:03(V:H).
Geogrid also provided necessary friction so that geomembrane could be securely
fastened on the surface of interior slope as the impermeable liner. Soil-filled and
hydro-seeded ACEBag™ was stacked and ACETex®
was placed for the face protection of
exterior slope. The vegetation has been displaying pleasant greenery with time and
turning into an eco-friendly environment because of the evidence of local species. The
area of the site was about seven hectares and the construction was completed within five
months only. The landfill operation has been initiated since January 2011 and by far it
functions very well.
Eco-MaterialsGeogrid (ACEGrid
®), Soil Bag (ACEBag™), Drainage system (Drainage Pipe,
Drainage Ditch), Geotextile (ACETex®
)
LandfillConstruction
25
The SolutionA mechanically stabilized earth (MSE) buttress was determined for this project;
the geogrid wrap-around reinforcing method was used. The design concept
was to use in-situ materials to deal with in-situ problem. The designed buttress
should function as a retaining wall, a training levee, an access road, and an
environment keeper. The overall MSE buttress structure had a width of 20m at
the foundation and 6.6m at the crest, on which a 6m wide PC pavement was
constructed as debris cleaning access. With an average slope of 7.96%, the
total length of the structure was 177m; the buttress extended and shielded
15m of the tunnel portal in length, and the end point of the buttress was 4.3m
higher than the tunnel roof.
1
0.5
Road Surface
Soil Bag
ACEG
rid +
ACE
Tex®
®
Drainage Pipe
The ContributionNatural propagation has vegetated and enhanced the appearance of the MSE
buttress. Over the years, the structure has experienced more than fifteen (15)
typhoons and the debris flow caused by them. Its overall performance and
current status proves itself an adequate and effective protection for debris flow.
The ProblemThe boundary of the conservation area was close to the proposed site of
construction, which limited the available working space and the size of
structure to be built. According to the construction history of the site,
gabion and earth dyke were practically proven ineffective. Therefore, the
Miaoli County Government wanted a different and effective structure to
keep the debris in the basin; and access for debris cleaning must be
considered in the design.
The BackgroundThis project was located at the toe of the Houyan Mountain, between
the western portal of the Houyan Mountain Tunnel and the nature
conservation area. The geologic situation of the mountain was naturally
unstable. Over the years, extreme torrential rain had made the area
even more vulnerable; debris flow became a threat to the environment
and the road close by. A debris basin was found beside the tunnel
portal as a protective measure. However, frequent typhoon invasion
and concurrent of debris flow broke the protective barrier between the
existing road and the debris basin again and again.
Reinforced Earth Buttress for Debris Flow Protection in Miaoli, Taiwan
OtherApplication
Guard Curb
OtherApplication
26
Landscape Engineering of the Maple Garden – Taichung, Taiwan
Considering the overall project requirements in cost-efficiency,
construction convenience, environmental friendliness, and landscape
beautification, the applications of geosynthetic products and relevant
engineering methods were the most suitable and feasible approach to
carry out the work. The project largely adopted the various
geosynthetic products such as flexible woven geogrid (ACEGrid®
),
geotextile fabric (ACETex®
), soil bag, vegetation mat (ACEMat™),
geomembrane, etc. in reinforcing and enhancing the landscape.
Rather than building traditional RC retaining wall, the surrounding wall
and slope of the opening were built with wrap-around reinforcing
method with geogrid (ACEGrid®
), geotextile (ACETex®
), and soil bag
forming mechanically stabilized earth wall (MSEW) and reinforce soil
slope (RSS), to support the loading coming from the road and sidewalk
above and around the Maple Garden, and to provide rooms for
vegetation on the wall and slope surface. This method took advantage
of in-situ soil to cut down the construction time and cost, and greatly
reduced the use of concrete. Moreover, geomat (ACEMat™) and
gabion were incorporated in the green landscape building, to serve as
a medium for vegetation and erosion control and shape the outline of
the landscape. Various trees and shrubs were planted to further
beautify and enrich the appearance of the park.
Geosynthetic product applications play a major role in building the park, and
significantly contribute to the concrete reduction and environmental
friendliness demand of the Maple Garden project; and the use of in-situ
materials and geosynthetic products brings convenience to the construction
and brings down the cost at the same time. Reshaping by the ecological
engineering methods, the project has successfully converted a problematic
ground opening to an attractive and environmentally-friendly scenic site. It not
only provides a recreational place for the general public, but also serves as an
urban drainage regulator in case of flood. Moreover, the vegetation planted
throughout the garden has increased the city’s green coverage by 28,000m²,
and contributed to lowering the urban heat island effect. This creative thought
and construction of turning a problem into an achievement has gained many
awards and recognitions from the construction and geosynthetic industries in
Taiwan. And it further wins the 2013 FIABCI Prix d’Excellence Award in the
Public Infrastructures/Amenities Category at the 65th FIABCI World Congress
(2014), Luxemburg. Started as a remedy and ends up with glory, the Maple
Garden project is beyond construction, it is in fact a meaningful and
remarkable art.
Furthermore, a detention pond of 200,000m³ was to be constructed and
connected to the city drainage for regulation of flood. In order to merge with
the landscape naturally, geomembrane, soil bag, and gabion were used to
construct an ecological detention pond to fulfill this demand. A restaurant with
a circular design front was built at the inner corner, merging with the
reinforced wall and facing the pond; an artistic exhibition center was built at
the entrance of the park beside the Taiwan Boulevard; these building
structures not only enhanced the function of the park, but also added some
elements of civilization and culture to the atmosphere. Walkways were
constructed with different methods at different sections in the park. Crushed
aggregate, timber, and wood chips were used in permeable pavements
beside the pond. The perimeter sidewalk built around the pond was about
388m. All these artificial, but natural, settings built up the beauty and spirit of
the Maple Garden.
A creative, exciting, and feasible idea was proposed to solve all
concerns with given constraints and conditions. The idea was to make
use of such landform to build a multifunctional park below ground
level; serving the functions of flood detention, exhibition, recreation,
park, and regulation of air quality of the city.
Environmentally-friendliness and concrete reduction were the main
foci of the landscape engineering concept for the project. This idea
was adopted by the Taichung City Government, and hence the land
was re-planned accordingly.
The Maple Garden project is the first and only recreational park below
ground level in Taiwan. It is a local landmark on the busy Taiwan
Boulevard in Taichung City. With a land area of 30,000m², it was the
proposed site for the Taichung International Expo Center; however, for
some reasons the project was ceased and cancelled after excavation.
As a result, a huge and dangerous boomerang-shaped ground
opening, with a depth of about 20m, was left on site. The opening was
seriously affecting the city’s appearance, threatening citizen’s safety,
and limiting the usage of the land, landform-wise and budget-wise.
The local government was under the pressure of the general public.
Something had to be done in a short time and within the budget.
www.geoace.com sales@geoace.com
ACE Geosynthetics
Note: The information provided herein is accurate to the best knowledge of the company and is given out in good faith. All the information contained is intended as a general guide only to use of such products and we do not accept liability for any loss or damage however arising, which results directly or indirectly from use of such information. ACE Geosynthetics has a policy of continuous development thus information and product specification may change without notice.
2016/08