Application of Simulation in Construction Processes King Saud University Engineering College Civil...

Application of Simulation in Construction

Processes

King Saud UniversityEngineering College

Civil Engineering Department

-CE 613-Planning and Modeling of Construction

Presented by Dr. Khalid Al-Ghtani

Application of Simulation in Construction Processes

Outline

Assignment- Earthmoving simulation by using Cyclone

Simulation Model for some construction process

Simulation Software used in Construction

Introduction

Introduction

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•Construction process is different from other engineering process because it is discrete and difficult to control the input.

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•Many factors affect the productivity from weather, skills of labor, management of the work and other factor.

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•In order to determine the productivity and time of construction process, many methods are used such as historical data, charts, tables and other methods. Simulation is one of the accurate methods that are used in this matter.


Much software was developed in the purpose of simulation. The application of simulation was applied first in the field of manufactory because of it has continues process. Then it started to applied in construction field with some modification.


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•First was that the simulation languages that are developed designed for the process interaction paradigms. •So that

languages suitable for manufactory not construction process.

•Some construction-oriented simulators such as CYCLONE, RESQUE, COOPS, and STROBOSCOPE, etc, are developed in order to address this issue.

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•Second, construction process needs to concept of activities similar to CPM.

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•Finally, because the previous systems are based on system not language, some difficulties are faced in order to model some complex construction process.

There are three major constrains that limit from spreading the use of simulation in construction field.


Cyclone STROBOSCOPE Java

SimEarth Believe Network

Five simulation systems that used in construction will be discussed which are

Cyclone

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•CYCLONE is one of the software that is designed to construction process. It stands for CYCLic Operations NEtwork.

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•The definition of Cyclone is explained in Purdue University web site which is “It is a modeling technique that allows the graphical representation and simulation of discrete systems that deals with deterministic or stochastic variables.” (Purdue University)

Cyclone

• Basically Cyclone convert abstracts reality of construction process into graphical representation by dividing the process into discrete pieces or work task and by representing how these interact.

• The cyclone graphical elements are represented in Table1 • Description of each of these components is shown in

Function column. • There are rules for the logical that govern the relation

between these elements.

Cyclone

Table 1 Cyclone Elements (source: Purdue University)

Cyclone

Table 1 Cyclone Elements (source: Purdue University)

CycloneIn the web-sit tutorial explain the procedure to define the Network model and Modeling construction process, which are:

Define work task composing a processEstablish logical relationship between the work tasksWork task use resources and require time to be

completed, this fact is accounted into the model by supposing that entities flow thorough the network, are delayed by work tasks, wait for processing, etc. When they are served (or used) by each work task they continue flowing through the network.

Cyclone

The procedure for Modeling Construction Processes is:

Define resources Identify work tasks in the process (work tasks

with which resources are involved)

Determine the logic of the processing of resources

Build a model of the process

Cyclone

In Cyclone software, the user needs 3 basic graphical elements each with a specific meaning and models a specific happening

1. ACTIVE STATE: Models a work task, and is represented in graphical notation as a SQUARE

2. IDLE STATE: Models a entity waiting for processing, and is represented in graphical notation as a CIRCLE

3. FLOW DIRECTION: Models where resources flow after being processed. It is represented by a directional ARC (arrow)

Cyclone

A flow unit traverses a CYCLONE network with the following effects:

Waits in QUEUE nodes for processing Initiates (or signal) the processing of a work task Generate other entities where they traverse a QUEUE-

GEN node Get consolidated with other flow units when they pass a

CONSOLIDATE Function Register productions where they pass a function

COUNTER

Cyclone

Modeling by using CYCLONE depends on the user how to present the construction process. Sometime the user uses the entities to measure the outcome materials rather than use the equipment or labor. MicroCYCLONE does not distinguish between entities, so up to the user to collect the statistical data and use proper logic of the process. To learn more about this software, visit the Cyclone Tutorial web-site on Prude University (Purdue University).

STOPSCOPE

• STROBOSCOPE is stands on STate and ResOurce Based Simulation of COnstruction ProcEsses.

• It is developed by Ioannou and Martinez (Ioannou, Martinez, 1996).

• The feature of this system over CYCLONE is that it is based on Object Oriented language.

• Also, it is include a cost as a factor to compare different resources number in simulation.

• There are some application of these model represented by Ioannou and Martinez (Ioannou, Martinez, 1996).

Simulation using Java

• Sawhney, Deshpande, and Mund used Java language as tools for simulation.

• They described a prototype component-based architecture for construction simulation (Sawhney, Deshpande, and Mund, 2000).

• The JavaBeans technology is based on Java and provides a means of creating and using Java classes as software components.

Java offers several features that are ideally suited to the implementation of advanced discrete-event simulation architectures and reusable simulation software components. Java based simulation results in creation of objects.


• JavaBeans provide the functionality of the CYCLONE modeling element were developed.

• Figure 1 show the JavaBeans developed for the CYCLONE modeling elements.

• Also, Table 2 show the key properties associated with the CYCLONE JavaBeans (Sawhney, Deshpande, and Mund, 2000).


Figure 1 JavaBeans for

the CYCLONE Modeling Elements (Source: Sawhney,

Deshpande, and Mund,

2000)


Table 2: Properties of the CYCLONE Beans (Source: Sawhney, Deshpande, and Mund, 2000)

JAVABEAN PROPERTY

JCycloneQueue Capacity

JCycloneNormal Service Time

JCycloneCon No. of Entities

JCycloneGen No. of Entities

JCycloneCount No. to Count

JCycloneCombi Service Time, Priority

SimEarth simulation system

• SimEarth simulation system was developed by Marzouk and Moselhi, which integrate fuzzy clustering and computer simulation, in order to model earthmoving operations utilizing object-oriented features and discrete event simulation.

• The main purpose of Fuzzy clustering is to provide realistic estimates of haulers’ travel time in order to get accurate simulation results (Marzouk and Moselhi, 2001). o Figure 2 illustrates the system componentso Figure 3 shows the screen of the software.


Figure 2: SimEarth: Components and Data Flow (Source: Marzouk and Moselhi, 2001)


Figure 3: Haul Trip Screen Menu (Source: Marzouk and Moselhi, 2001).

Belief Networks for Construction

• This system is combination between the simulation and improvement the resource performance in order to get a high productivity.

• So the system consists from two parts which are simulation part and belief network part.

• The function of simulation model is to describe the construction processes and their components.

• Also, the function of simulation model is to determine the effect that changes in resource configuration have on the model performance.

• The function of other part, belief network, is to provide diagnostic analysis of the performance and recommendations for changes to the model.

• Such as modifications are selecting alternative resources and resources quantities (McCabe, 1998).


• The main feature of this system is the automation improvement of resource performance.so,

• this method is focus on using the factor of resource performance rather using objective of lower cost or shorter time.

• the concept of this method that ultimate efficient of resource will lead to get the best combination between shorter duration and lower cost.

• the approach is repetitive, and will provide the modeler with results even if user-defined constraints related to performance limits are not met (McCabe, 1998).


• This system use Visual Basic as integrated software for MSBN Microsoft Belief Network Version 1.001, the belief network modeling and evaluation environment used for the prototype, AweSim Version 2.0 by Pritsker CorporationÓ (Pritsker, O'Reilly & LaVal 1997),

• the simulation language that are used, and Microsoft Access, relational database that are used to store the input resource assignment and corresponding output of each simulation run (McCabe, 1998).


There are many Model was developed to represent the construction process to use it in simulation. The following is some of these models with its references for more detail.

Bridge Damp Earthmoving

Figure 4 and Figuer 5 represents the process of earthmoving in bridge project. The following statement is from the case study that described in Ioannou and Martinez paper (Ioannou and Martinez, 1996).



“The existing bridge cannot support heavy trucks and the contractor must provide one or more new temporary low cost bridge(s) for his trucks to cross the river.

There are two types of temporary bridges to choose from. A Type I bridge costs $95,000 and can hold only one truck at a time. Moreover, trucks must pass very slowly (it takes 1.75 minutes to cross over). A Type II bridge costs $165,000 and can hold up to six trucks at the same time. Because the bridge is narrow, however, these trucks must be traveling in the same direction, separated at least 0.30 minutes from each other. The time to cross a Type II bridge is also 1.75 minutes.



The earthmoving contractor must determine the type and number of bridges that gives the lowest project cost and the corresponding total cost and time to complete the project.

Based on the contractor’s past experience with one-way bridges, it appears that the best crossing policy is to let all trucks going in one direction cross the bridge without reversing the flow of traffic for as long as there is a queue. When no more trucks need to cross the bridge in the current direction and the bridge is clear, the trucks in the other direction are allowed to cross in the same manner.


Figure 4: Cyclone Network for Dam Construction Simulation Model (Source: Ioannou and Martinez, 1996).


Figure 5: Earthmoving Layout for Dam Construction (PROOF Animation) (Source: Ioannou and Martinez, 1996).


Steel Erection Model

Slaughter and Eraso use also the simulation technique in purpose of assisting the operational and economic impacts of technological innovations. They described the process of steel erection and the potential benefits and costs of eight specific erection innovations, and any changes that may be required in material, equipment, or process to use them. The objective of using simulation method to prove the significant improve of the use of some technical innovations of steel erection. (Slaughter, Eraso, 1997)


Steel Erection Model

On the other paper, Sawhney, Mund, and Marble illustrate a Petri Net based hierarchical and modular modeling and analysis technique that can be used for simulation of complex construction processes. The objective of this paper is to show up the advanced features of Petri Nets and their utilization in the modeling and analysis of a structural steel erection process (Sawhney and Mund and Marble 1999). The following Model is represented in their paper. Figure 6 illustrates the element of Petri Nets. Figure 7 illustrates the main erection steel model. Figure 8, 9, and 10 are subpart from Figure 7 which gives more details of the process.


Figure 6: Modeling Elements of Classical Petri Nets (Source: Sawhney and Mund and Marble 1999)


Figure 7: Petri Net Main Model of Steel Erection Process (Source: Sawhney and Mund and Marble 1999).


Figure 8: Erection Tasks Sub-Model (Source: Sawhney and Mund and Marble 1999).

Figure 9: Crane Moving Sub-Model (Source: Sawhney and Mund and Marble 1999).


Figure 10: Detailing Tasks Sub-Model (Source: Sawhney and Mund and Marble, 1999).


Bridge Process Simulation Model

The CYCLONE network for this case is shown in Fig. 11.

Rene A. Yamin-Lopez developed a model to simulate the construction process of bridge. When examining the construction of the bridge, set of main cycles were identified and these are described as follows:

Deck box welding cycle. Wing assembly cycle. Pylon cycle.Install deck box.Install cables.


Figure 11: Alamillo Bridge Construction Network - CASE 1 (Source: Yamin-Lopez, retrieved April, 12th, 2003)


• In order to demonstrate the methodology of simulation, the following is a case study of earthmoving is used to estimate the duration for this activity.

• This case study is used by Ioannou and Martinez (Ioannou and Martinez, 1996).They use this case by using STROBOSCOPE.

• Repeat this case study again by using UM-Cyclone tools to perform the simulation analysis.

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EXAMPLE

Given the following information on a shovel/truck operation, (a) calculate the number of trucks theoretically required and the production of this combination; (b) calculate the expected production if two trucks are removed from the fleet.– Shovel production at 100% efficiency =371 BCY/h

(283 BCM/h)– Job efficiency=0.75– Truck capacity =15.3 BCM– Truck cycle time, excluding loading = 0.5 h

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Determining the Number of Haul Units Needed

• Loading time, however, should be calculated by the use of Equation 4-14 or 4-15.

– Load time = Haul unit capacity / Loader production at 100% efficiency (4-14)

– Load time =Number of bucket loads × Excavator cycle time (4-15)

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• The number of trucks theoretically required to keep a loader fully occupied and thus obtain the full production of the loader may be calculated by the use of Equation 4-16.– Number of haulers required (N) = Haul unit

cycle time / load time (4-16)

CE 417 King Saud University 44


• The expected production in this situation may be calculated by the use of Equation 4-17.

• In performing this calculation, use the precise value of N, not its integer value.

– Expected production =Actual number of units / N = Excavator production (4-17)• (no. units less than N)

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EXAMPLE

Solution

(a) Load time = 15.3/283 = 0.054 h (Eq 4-14)

Truck cycle time =0.5 + 0.054 =0.554 h

Number of trucks required = 0.554/0.054

= 10.3 = 11 (Eq 4-16)

Expected production = 283 × 0.75= 212 BCM/h

CE 417 King Saud University 46

EXAMPLE

(b) With nine trucks available,Expected production = 9/10.3 × 212 = 186 BCM/h

(Eq 4-17)

Cyclone Network for Dam Construction Simulation Model (Source: Ioannou and Martinez, 1996)


Input Data of Case study

• “An earthmoving contractor needs to move 200,000 m3 of soil for the construction of a dam.

• Soil will be loaded at the borrow area using two types of heavy loaders.

• The soil is loaded into two types of heavy trucks that travel to the dam embankment, dump, and return empty.

• The density of the loose soil moved is 1690 kg/m3. • A total of 3 loaders and 11 trucks will be used on this job. • Tables 3 and 4 show the number and characteristics of

the loaders and trucks by type and model.


Input Data of Case study

• What is the time required to move 200,000 m3 of soil for the construction of a dam based on 3 loader and 11 trucks (Assuming 7 hours/day)?

• Use cyclone software


Table 3: Loader Data (Source: Ioannou and Martinez, 1996)


Table 4 : Truck Data (Source: Ioannou and Martinez, 1996)

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