Construction Process Simulation Research Articles

Development of a CityGML Application Domain Extension for Simulating the Building Construction Process

Virtual 3D city models can be stored and exchanged in the CityGML open data model. When dynamic phenomena in 3D cities are represented with a CityGML application domain extension (ADE), the objects in CityGML are often used as static background, and it is difficult to represent the evolutionary process of the objects themselves. Although a construction process model in building information modeling (BIM) is available, it cannot efficiently and accurately simulate the building construction process at the city level. Accordingly, employing the arrow diagramming method, we developed a CityGML ADE to represent this process. We extended the hierarchy of the model and proposed the process levels of detail model. Subsequently, we explored a mechanism to associate the construction process and building objects as well as the mechanism to automate construction process transitions. Experiments indicated that the building construction process ADE (BCPADE) could adequately express the characteristics of this process. Compared with the building construction process model in the architecture, engineering, and construction field, BCPADE removes redundant information, i.e., that unrelated to a 3D city. It can adequately express building construction processes at multiple spatiotemporal scales and accurately convey building object behavior during building evolution, such as adding, removal, merging, and change. Such characteristics enable BCPADE to render efficient and accurate simulations of the building construction process at the city level.

Study on support time in double-shield TBM tunnel based on self-compacting concrete backfilling material

Double-shield tunnel boring machine (TBM) typically supports surrounding rock structures using precast lining segments, pea-gravel backfilling and grouting, which can provide full play for the self-bearing capacity of surrounding rock. However, the risk of TBM jamming is increased by a lack of timely support. We propose a support method using self-compacting concrete backfilling material (SCCBM) instead of pea-gravel backfilling and grouting. In this paper, based on simulations of a TBM construction process, the support time and mechanical properties of the SCCBM are analysed. The deformation characteristics of surrounding rock are simulated using the viscoplastic creep model based on the internal variable thermodynamics theory. Creep parameters are obtained through the inversion analysis of displacement data collected at a construction site. The age-hardening process of SCCBM is simulated using the Mohr–Coulomb criterion, whose mechanical parameters change over time. Surrounding rock deformation, support system stress, yield region, surrounding rock stability, and the effects of the age-hardening rate of SCCBM are analysed. Additionally, the optimal supporting time is determined by comprehensively analysing surrounding rock deformation and supporting system stress. Overall, backfilling SCCBM with an optimal supporting time can not only reduce the deformation of surrounding rock and risk of TBM jamming, but also enhance the stability of surrounding rock.

Lean production theory-based simulation of modular construction processes

Abstract One way to encourage adoption of prefabrication and off-site manufacturing (OSM) techniques, such as modular construction, is to improve the efficiency of site operations, which makes the technology more attractive to non-adopters. Lean principles have been widely applied to improve the productivity and efficiency of construction operations, while simulation augments Lean theory by allowing its benefits and issues to be analyzed quantitatively before actual implementation. Thus, this study aims to conduct a detailed simulation study of modular construction operations, otherwise known as Prefabricated Prefinished Volumetric Construction (PPVC) in Singapore. In contrast with existing research, which are frequently focused on the barriers and drivers to the adoption of prefabrication, this study will provide and evaluate recommendations to improve modular construction efficiency through application of Lean concepts. A detailed baseline (As-Is) simulation model of an ongoing PPVC project case study was first developed. Lean Construction principles were then applied to the baseline simulation model. Key Lean Construction principles and concepts implemented includes Total Quality Management, E-Kanban based Just-In-Time deliveries, cross training and the use of construction robotics. Lean (To-Be) simulation models were developed based on the Lean Construction principles. The outputs from the baseline and Lean models were compared to assess the impact of the proposed improvements. The findings demonstrated that through the application of Lean concepts, reductions in cycle time and process time, and increases in process efficiency and labor productivity can be achieved. The case study also provides a detailed description of the simulation approach, which is a useful reference for future application of simulation in offsite construction research.

Construction Process Simulation and In Situ Monitoring of Dendritic Structure on Nanjing Niushou Mountain

For complex structures, where there are great differences between the structural form in the construction process and the design forming state, mechanical analysis of the construction process is required. The dendritic structure on Nanjing Niushou Mountain is taken as an engineering case study, with a narrow construction space, weak construction platform, and difficulty in setting the equipment in the site. A new construction method, self‐balancing elevating scheme, is introduced according to the special condition of the construction field. The lifting frame and the connection joint between the trunk and the branch employed in the self‐balancing elevating scheme are optimized according to the structure’s behavior. A construction monitoring scheme was adopted in this project to ensure construction safety. The maximum cable force and deformation occurred at the beginning of the lifting. The construction process simulation was conducted by space structure design software 3D3S. The analysis results were well consistent with the in situ construction monitoring results. The analysis results show that the self‐balancing elevating scheme could satisfy the construction requirement on the special construction condition and provide reference on future practical application.

BIM in Precast Construction: A Case Study of Highrise Residential Building

The study objectives are to analyze BIM application in the project practice and evaluate different implementation influence during the construction period. Building Information Modelling (BIM) combines various building information data in the model. It has a series of characteristics of visualization, coordination, simulation, optimization, and others. For the whole life cycle of building, BIM has prominent advantages in project management and operation management. The main research method is the case study for this paper. The case Forest City project reported BIM application on a typical high-rise condominium project in Malaysia. Two precast residential buildings executed the BIM tool for construction management. The participants tried to use the entire construction process simulation. They intend to obtain the best management method to improve their work efficiency and reduce project cost. From the Forest City project case study, the designers and engineers provided various precast components 3D presentation. It reduced rework through BIM clash detection. Main-con QS took off this project quantity accurately through the BIM platform. BIM technology helped relevant participants to improve work efficiency. The research implications are displayed a useful technology for precast construction management, such as BIM 3D/4D/5D functions.

The BIM-enabled geotechnical information management of a construction project

For the convenience of collaborative design, virtual construction, construction process simulation and management, Building Information Modeling (BIM) is becoming an important tool in civil engineering. The current BIM team seems to neglect the geotechnical aspect of the model, which can result in costly mistakes, especially when the project is infrastructure based. The barrier between the BIM team and the geotechnical data provider is the difficulty in extracting and assimilating data from the archived geotechnical data, which is mainly in the form of geotechnical investigation reports and geological sections. Furthermore, the geotechnical data exposed from the construction can not be linked to the original data conveniently to correct the interpretated errors in the geotechnical data, and the monitoring data cannot be combined with the original geotechnical data to find the development trend of the monitoring variables. All of this indicates that current management strategy of geotechnical data should be improved upon. Therefore, a management strategy that focuses on the full life cycle management of geotechnical data together with the BIM model to improve the accuracy of decision making in the design, construction, operation and management stages of a construction project is particularly important. In this paper, we put forward a management strategy of geotechnical data that can help to integrate geotechnical information into the BIM of a construction project in order to realize the full life cycle management of geotechnical information. In this strategy, the geotechnical data from the geotechnical investigation is archived in the form of a centralized geotechnical database and an informative geotechnical model. The centralized geotechnical database is targeted to manage the factual data, base data, result data, and metadata. The informative geotechnical model can facilitate the geotechnical being used in the three-dimensional visualization environment where the collaborative design and virtual construction are accomplished. We discuss the specific workflow of building a centralized geotechnical database and an informative geotechnical model. Finally, we use the management of the geotechnical data in a hydropower station for experimental studies to verify the proposed management strategy. The result shows that it is advantageous to manage the geotechnical data in the proposed management strategy for the BIM of a construction project.

Feedback Design of Temperature Control Measures for Concrete Dams based on Real-Time Temperature Monitoring and Construction Process Simulation

Crack prevention is a significant issue in the construction process of concrete dams. The vast majority of concrete cracks are related to temperature variations, and hence, temperature control is a primary method used to prevent cracks. This paper presents a new integrated concept, named Feedback Design (FD) of temperature control measures, which incorporates real-time temperature monitoring, temperature field simulation and construction process simulation in a large system to optimize a temperature control scheme for concrete dams. We used a fiber-optic Distributed Temperature Sensing (DTS) system to monitor the temperature variation process of typical dam monoliths in real time. By incorporating a genetic algorithm, neural network algorithm, and finite element theory, we proposed an intelligent inversion method to obtain thermal parameters of concrete dams based on the temperature monitoring data. Meanwhile, we built a simulation model of a concrete dam’s construction process based on a cycling network technique to obtain accurate construction environmental parameters. Finally, we simulated the temperature field of a typical dam monolith based on initial temperature control measures, inversion thermal parameters, and accurate construction environmental parameters. Temperature variance lines of typical points in the model obtained from the finite element method (FEM) accord well with the measured values obtained from the DTS system. We applied the FD approach to the Xiluodu arch dam located in southwest China to forecast the temperature fields and optimize the temperature control scheme of the dam blocks planned for pouring. The FD approach has been proven reliable and efficacious.

An integrated simulation and optimization approach for reducing CO2 emissions from on-site construction process in cold regions

Carbon dioxide (CO2) reduction has obtained worldwide attention due to the global warming effects and the mitigating means such as carbon tax. Among the CO2 emission sources, construction and building related activities consume a considerable amount of energy and produce a significant volume of greenhouse gases (GHGs). This paper proposes an integrated simulation and optimization approach to reducing CO2 emissions from the on-site construction process, which consists of three main steps: (i) construction process simulation, (ii) CO2 emission quantification, and (iii) labour allocation optimization. The construction process is simulated utilizing a discrete-event simulation (DES) platform, Simphony.NET, in order to quantify and analyze the amount of CO2 emissions produced by the construction process. Based on the simulation model, the crew sizes for labour-intensive activities are analyzed and optimized with respect to CO2 emissions, with a genetic algorithm (GA) employed as the method of optimization. The integrated simulation and optimization approach is capable of reducing CO2 emission through (i) the choice of the start-date of the construction, and (ii) labour allocation optimization. A case study in Edmonton, Canada, is used to demonstrate the effectiveness and applicability of the developed approach. Results indicate that the total measured CO2 emissions from on-site construction can be reduced by 21.7% in winter by optimizing labour allocation. This research thus proposes a generic methodology by which to measure and reduce CO2 emissions produced from construction process through labour allocation.

The Possibility of Using Neural Networks in Data Analysis Connected with Observation in the Construction Process Simulation

The subject of the article is to present the possibility of applying artificial neural network in analysis of observational data on the issue of simulation concrete supplies in construction industry. Neural networks allows a quick and efficient way to model phenomena at different levels of complexity. They can be used both in processes of well and poorly structured problems, knowledge of which is limited. The advantages of neural networks were transferred to the possibilities of defining probability distributions of individual tasks in cyclical building processes.The article presents the problem of concrete supplies for construction site, its elements and parameters which describe the process. The use of simulation in decision-making system was also demonstrated. One of the stages of creating simulation models is the adoption and verification of probability distributions that describe the elements of the system. In order to learn and predict the characteristics of probability distributions neural networks were used, that enable in the efficient and effective manner the implementation of further stages of simulation modeling. The article presents the results of applying the neural network and approach that enables their use.

Construction Stage Mechanical Performance Analysis of Long-Span Continuous Rigid Frame Bridge

Accurate simulation of construction process of continuous rigid frame bridge is a foundation to make a bridge built accurately. Based on the suit iteration method, this paper used MIDAS to built a 3D finite elements model, the internal force and deformation results of each construction stage was obtained. This study provided a good theoretical reference for the control of long-span continuous rigid frame bridge construction..

Evaluation of queuing systems for knowledge-based simulation of construction processes

Abstract During the course of a construction project, there are many situations in which formation of waiting lines or queues is inevitable. The effect of resource delays in queues on the overall project completion time and cost has motivated researchers to employ simulation for analysis of queuing systems in order to identify the best operational strategies to reduce the time wasted in queues. Providing proper and timely input data with high spatial and temporal accuracy for queuing systems simulation enhances the reliability of decisions made based upon the simulation output. Hence, the presented paper describes a methodology for collecting and mining of spatio-temporal data corresponding to the interactions of queue entities to extract computer interpretable knowledge for simulation input modeling. The developed framework was validated using empirical datasets collected from a series of experiments. The extracted relevant knowledge from the queuing system entities was used to update corresponding simulation models.

Research on Simulation and Analysis of Tensioning Process of Suspender for Combinative Bridge with V-Type Pier Continuous Rigid Frame and Arch

The combinative bridge with V-type rigid frame continuous concrete beams and concrete filled steel arch bridge is a hyperstatic structure at internal and external, the construction process is complex, the structure is occurring system transformation with construction process. The tensioning process of hangers has a direct impact on the force of suspender final bridge and the stress state of the structure. The influence of deformation and stress of structure are studied with one-step tensioning and multi-step tensioning, Based on finite element simulation of construction process for the combinative structure with V-type rigid frame and arch of Nianchu River Bridge. The tensioning construction process of suspenders is forward on considering the actual situation of the bridge.

Discrete-Event Simulation versus Constrained Graphic Modelling of Construction Processes

Effective construction project planning and control requires the development of a model of the project’s construction processes. The Critical Path Method (CPM) is the most popular project modelling method in construction since it is relatively simple to use and reasonably versatile in terms of the range of processes it can represent. Several other modelling techniques have been developed over the years, each with their own advantages and disadvantages. Linear scheduling, for example, has been designed to provide highly insightful visual representations of a construction process, but unfortunately is largely incapable of representing non-repetitive construction work. Discrete-event simulation is generally agreed to be the most versatile of all modelling methods, but it lacks the simplicity in use of CPM and so has not been widely adopted in construction. A new graphical constraint-based method of modelling construction processes, Foresight, has been developed with the goal of offering the simplicity in use of CPM, the visual insight of linear scheduling, and the versatility of simulation. Earlier work has demonstrated the modelling versatility of Foresight. As part of a continuing study, this paper focuses on a comparison of the Foresight approach with discrete-event construction simulation methods, specifically Stroboscope (a derivative of CYCLONE). Foresight is shown to outperform Stroboscope in terms of the simplicity of the resultant models for a series of case studies involving a number of variants of an earthmoving operation and of a sewer tunnelling operation. A qualitative comparison of the two approaches also highlights the superior visual insight provided by Foresight over conventional simulation, an attribute essential to both the effective verification and optimization of a model.

Study of the stability of tunnel construction based on double-heading advance construction method

The deformation and significant settlement of surrounding rock often occur during tunnel construction with the condition of abundant water and weak cementing sand. In order to study the construction method and stability under such soft stratum, this article takes Taoshuping tunnel as the engineering background and puts forward a new tunnel construction method—double-heading advance construction method by comparing the advantages and disadvantages of various traditional construction schemes. The numerical simulation of tunnel construction process using this method is carried out to illustrate the rationality and feasibility of the method. The conclusions are drawn by comparing the numerical simulation results with the field monitoring data analysis. The numerical simulation results show that the maximum settlement value caused by excavation construction is in the parts 5 and 6 of the upper half-section and the part 7 of the central section. The settlement values of parts 5, 6, and 7 accounted for 32.4%, 24.3%, and 18.9% of the total settlement values, respectively. So, the supporting measures for double-heading advance excavation construction of these three parts should be strengthened properly. The stress of the right hance changes greatly before and after the demolition of temporary support. The maximum positive value of stress is 23 kPa and the maximum negative value of stress is −32 kPa. Therefore, the length of temporary bracing should be strictly controlled during construction and the monitoring of the right hance area should be strengthened. Furthermore, it is necessary to strengthen the supporting measures and monitoring in the right spandrel area as the surrounding rock pressure in the right spandrel area is higher than the left spandrel area. The optimum excavation height of the upper half-section in Taoshuping tunnel is determined to be 5.4 m and the reasonable excavation distance between parts 1 and 5 is determined to be 25–30 m by parameter optimization. Finally, the variation law of numerical simulation and field monitoring results is consistent, which shows that the double-heading advance construction method has a better effect on the stability control of surrounding rock, and the rationality and feasibility of this method are validated effectively. Therefore, the double-heading advance method is suitable for tunnel construction in the sand stratum with rich water and weak cementation, and the successful implementation of this method in Taoshuping tunnel also provides a reference for subsequent tunnel construction in the sand stratum with rich water and weak cementation.

Study of Permanent Thermal Insulation for Arch Dam in Cold Region

For virtue of small volume and fast speed of construction, arch dam is the most suitable dam type in cold region, where construction period is relatively short each year. Low average value and large amplitude of atmospheric temperature make temperature stress distribution of arch affect directly by thickness of permanent insulation material as while as the time of thermal insulation. Extreme climate lead to stricter external insulation requirement for cold region arch than these in common district, however, thermal insulation will increase the burden of artificial cooling and extend the construction period. Therefore, it is complicated and critical for arch dam crack prevention to study on permanent thermal insulation. In view of this, finite element method was applied for simulation of construction processes of a practical project in cold region. Influence of permanent thermal insulation layer thickness and selection of insulation time is analyzed, in order to provide basis for permanent thermal insulation optimization.

Modeling of combined thermal and mechanical action in roller compacted concrete dam by three-dimensional finite element method

A combined thermal and mechanical action in roller compacted concrete (RCC) dam analysis is carried out using a three-dimensional finite element method. In this work a numerical procedure for the simulation of construction process and service life of RCC dams is presented. It takes into account the more relevant features of the behavior of concrete such as hydration, ageing and creep. A viscoelastic model, including ageing effects and thermal dependent properties is adopted for the concrete. The different isothermal temperature influence on creep and elastic modulus is taken into account by the maturity concept, and the influence of the change of temperature on creep is considered by introducing a transient thermal creep term. Crack index is used to assess the risk of occurrence of crack either at short or long term. This study demonstrates that, the increase of the elastic modulus has been accelerated due to the high temperature of hydration at the initial stage, and consequently stresses are increased.

Monitoring Analysis of Tunnel Construction in a New Subway Line Down-Through an Existed Line

For a practical engineering in which the tunnel of Subway Line No.7 between Guangqumen outside Station and Shuangjing station is down through Shuangjing Station of existed Subway Line No.10, numerical simulations of construction process of the tunnel have been investigated by FLAC 3D software and compared with site monitoring data. The sedimentation curves of the earth's surface along the cross-sectional and longitudinal direction are obtained, which show that all results including numerical simulation and site monitoring are accord with the data from the Peck formula. At the same time according to numerical computation, some relations between width and depth of excavating a tunnel are discussed. All these have important significant to theoretical research and engineer practice of subway construction.

Finite Element Analysis of Composite Soil-Nail Retaining Structure in Foundation Pit Engineering

Base on general three dimension nonlinear numerical simulation software, mechanism of composite soil-nail retaining structures in foundation-pit engineering are analyzed in this paper. Research contents include construction process simulation of excavation by steps, soil nailing installation and panel manufacture etc. Tension distribution range of soil layer, bottom heaving in the pit and axial force distribution along nail etc. are analyzed through the comparison of mechanical characteristics between computational results and field test data in the case of micro pile composite soil-nail support engineering. The action mechanism and working performance of composite soil-nail retaining support are also systematically studied and theoretical basis can be provided in optimal design, popularization and application.

Optimization Simulations of Support System by Composite Soil-Nail Retaining Structure

Mechanism of composite pre-reinforced micro pile soil-nail and pure soil-nail retaining structure in foundation-pit engineering are analyzed in this paper through general three dimension nonlinear numerical simulation software. Research contents include whole construction process simulation of construction such as excavation by steps, piles and soil-nail installation and panel manufacture etc. By the comparison of mechanical characteristics between the pure soil-nail and composite soil-nail retaining structures in the same slope engineering example, differences of tension distribution range of soil layer, deformation features, mechanical characteristics of support and axial force distribution along nails etc. are analyzed. Research results are verified by in-site projects and measured data. The action mechanism and working performance of composite soil-nail retaining support are also systematically studied and theoretical basis can be provided in the similar application.

Brood comb construction by the stingless bees Tetragonula hockingsi and Tetragonula carbonaria

Tetragonula hockingsi and T. carbonaria are two closely related species of Australian stingless bees. The primary species-specific character is the architecture of the brood comb. The brood comb of T. hockingsi is an open lattice comprising clumps of about ten cells that are connected by vertical pillars. In contrast, in T. carbonaria the brood comb is a compact spiral in which all brood cells (except on the margins) are connected by their walls to adjacent cells at the same height. We made detailed observations of the cell construction process in two colonies of each species. From these observations we formed a species-specific hypothesis about the algorithm followed by the bees during cell construction. The two algorithms allowed us to make predictions about the locations of new cells. Both T. hockingsi and T. carbonaria share a preference for constructing new brood cells in the clefts formed by two or three adjacent existing brood cells, but there are differences in detail for other components of the building process. The fundamental difference in the cell construction process of the two species is that for T. hockingsi, when a cluster of cells contains ten cells, the next cell added to the cluster is offset upwards by half a cell length, or, less often, a vertical pillar rather than a new cell is constructed. In T. carbonaria, cell construction is continuous at the comb margin so that there are no gaps between cells. Furthermore, it seems that T. hockingsi only makes use of local knowledge of the brood comb when deciding to place new brood cells, whereas T. carbonaria could make some building decisions based on knowledge of the total structure. We translated the species-specific algorithms into agent-based lattice swarm computer simulations of the cell construction process for the two species. These simulations produced representations of brood combs that are similar to those seen in vivo, suggesting that our biological rules are realistic.