Construction Schedule Research Articles

Analysis of Design Change Mechanism in Apartment Housing Projects Using Association Rule Mining (ARM) Model

Apartment housing occupies the highest proportion of the domestic construction market and significantly influences the flow of the real estate market. Frequent design changes and reconstruction in new apartment housing projects lead to an increase in construction cost and schedule, and a decline in design and construction quality, which is an important issue affecting the quality of use for occupants. The causal relationship of design changes and error in new apartment building projects has not been previously identified. Accordingly, design changes management activities in the construction phase using reactive manner are a critical risk that causes the productivity of the project to deteriorate. In this study, a complex and non-linear causal relationship between the design change factors was investigated using the association rule mining technique (ARM), a type of data mining technique. In particular, the associated relationship between design change factors that can be changed according to conditions that significantly affect the productivity and performance of projects, such as a contractor’s ranking in the field, contract price which means the project size, and contractor selection methods, was identified. The association rule between the design changes at the construction phase derived in this research can be used as a guide to identify and minimize the risk of design changes in advance.

A solution for the rational dispatching of concrete transport vehicles

The amount of concrete needed in the construction of projects is enormous. The concrete dispatching in construction is, however, chaotic and causes grievous waste due to the tight construction schedule, heavy tasks, and improper transport vehicle dispatching by the constructor. This paper proposes a more realistic objective function in the vehicle dispatching algorithm and offers a solution to the rational dispatching of concrete transport vehicles. The analysis of the calculation example validates the feasibility of the built model, which provides more appropriate dispatching and more balanced distribution, meets the needs of the worksite and mixing station to the greatest extent and improves the level of project refinement and process management. Therefore, the model is worth promoting in future practice.

Experimental study of a new assembled integral concrete–steel open-web sandwich plate composite bridge

This study introduces a new type of bridge structure—the assembled integral concrete–steel open-web sandwich plate composite bridge (COSPB), which is composed of a concrete slab,steel Vierendeel beams (SVBs, with top chords, bottom chords and shear keys), and studs (used for connecting SVBs and concrete slab). The bi-directional SVBs form a spatial steel grid structure, which can be used as the formwork for concrete slab casting, and divided into prefabricated units to allow on-site assembly after prefabrication in factory, leading to the reduction of on-site construction workload and the acceleration of the construction schedule. To understand the flexural behavior of this kind of structure, a static experiment was conducted on a 10-m-span full-scale test specimen with simply supported boundaries to investigate the deflection, strain distribution, and failure mode. The test results showed that there was still a large safety reserve for the flexural capacity of the section after the bottom chord of the steel–concrete composite Vierendeel beam (SCVB) began to yield. The ratio of the ultimate load to the yield load was 1.56. No concrete crushing and large area cracking were observed during loading, and the structure had good ductility. The ultimate flexural capacity of the SCVB was analyzed by the method of cross-sectional analysis, and the results were in good agreement with the test results. Finally, based on the test results, the ultimate flexural capacity and stiffness of the bridge were discussed using the Chinese Highway Bridge Design Code.

Investment Risk Analysis of Jakarta - Cikampek II Selatan Toll Road

The availability of infrastructure is important in supporting economic activities. The toll road is one of the infrastructures that have undergone extensive development over the past five years. It benefits the Indonesian community by shortening travel time and increasing economic growth. Toll road development is a long-term investment that requires very large costs and a long payback period. Potential risks could hinder the development of toll roads and would delay the payback period further. Due to the delay in the construction schedule, there is an estimation difference between the beginning financial feasibility in 2017 and the adjustment in 2022, when the toll road is currently under construction. Financial feasibility analysis is not complete without risk analysis. Thus, investment risk analysis has to be done. The results showed a payback period of 9.65 years, a discounted payback period of 19.41 years, an NPV of IDR 4,759,916 Trillion, and an IRR of 11.63% is greater than 10.65%, the cost of capital. Since all the results exceed the acceptance criteria, this toll road project is feasible, although it is calculated using the latest adjustment assumptions. However, from the comparison result, the adjusted has a lower IRR and discounted payback period compared to the beginning (12.32% and 18 years). Using sensitivity analysis, 3 sensitive variables are identified to impact NPV results greatly. According to the scenario analysis result, each of the scenario’s payback period, discounted payback period, NPV, and IRR is considered to be accepted. It showed that the toll road project is feasible in pessimistic, most likely, and optimistic scenarios. Based on the risk management result, there are 1 extreme risk, 2 high risks, 5 moderate risks, and 1 low risk. A risk mitigation plan helps reduce each potential risk's probability or impact.

RS-SVM Machine Learning Approach Driven by Case Data for Selecting Urban Drainage Network Restoration Scheme

ABSTRACT Urban drainage pipe network is the backbone of urban drainage, flood control and water pollution prevention, and is also an essential symbol to measure the level of urban modernization. A large number of underground drainage pipe networks in aged urban areas have been laid for a long time and have reached or practically reached the service age. The repair of drainage pipe networks has attracted extensive attention from all walks of life. Since the Ministry of ecological environment and the national development and Reform Commission jointly issued the action plan for the Yangtze River Protection and restoration in 2019, various provinces in the Yangtze River Basin, such as Anhui, Jiangxi and Hunan, have extensively carried out PPP projects for urban pipeline restoration, in order to improve the quality and efficiency of sewage treatment. Based on the management practice of urban pipe network restoration project in Wuhu City, Anhui Province, this paper analyzes the problems of lengthy construction period and repeated operation caused by the mismatch between the design schedule of the restoration scheme and the construction schedule of the pipe network restoration in the existing project management mode, and proposes a model of urban drainage pipe network restoration scheme selection based on the improved support vector machine. The validity and feasibility of the model are analyzed and verified by collecting the data in the project practice. The research results show that the model has a favorable effect on the selection of urban drainage pipeline restoration schemes, and its accuracy can reach 90%. The research results can provide method guidance and technical support for the rapid decision-making of urban drainage pipeline restoration projects.

Exiting the elephant: hearing the participant voice in qualitative data collection

ABSTRACT Data collection in qualitative research is intended to capture the participant experience in relation to defined phenomena. Whilst attention is given to the different ways of gathering qualitative data, the presence of the researcher is a common feature. However, the researcher does not hold an inert position in the data collection process and may influence the type and level of data obtained. This paper highlights and explores the issue of researcher presence by suggesting a strategy to distance the researcher from the data collection frame via self-governing focus groups. Developed in a study examining vocational student experience in further education, a data collection method is proposed which aims to reduce the influencing factor of the researcher. A self-administered structured question schedule replaces the interviewer to promote authentic access to the participant voice in an environment which is familiar, comfortable and safe. Consideration is given to the construction of the question schedule and recording procedure which aims to stimulate inclusive and unhindered contributions, as well as maintaining the research focus. The analysis of contributions indicates that by standing back, the researcher can see authentic customary social processes which reveal a meaning of the phenomena for the participants.

Wind Design of Composite Plate Shear Walls/Concrete Filled (SpeedCore) Systems

Composite steel plate shear walls/concrete filled (C-PSW/CF), also known as the SpeedCore system, are a composite solution for the design of mid- to high-rise buildings. A C-PSW/CF system consists of steel plates (web and flange plates) and an infill concrete core. The composite interaction between steel plates and concrete core is developed by either tie bars or tie bars and shear studs. Generally, in low- to mid-rise buildings (less than 15 stories), planar (uncoupled) C-PSW/CF are adequate for resisting lateral loading and deformations. Coupled C-PSW/CF become more prevalent in mid- to high-rise buildings when increased lateral stiffness is desirable. The steel parts of a SpeedCore system (steel plates, tie bars, and shear studs) are prefabricated in the shop and then transported to the site for assembly and erection. The erected empty steel module serves as falsework and formwork during construction and concrete casting, which reduces construction schedule considerably. This is a major advantage of SpeedCore systems, especially when compared with conventional reinforced concrete core systems. This paper presents the wind (nonseismic) design requirements and procedures for planar uncoupled and coupled C-PSW/CF systems. It includes a design example of a 15-story building located in Chicago, Illinois, using both uncoupled and coupled systems.

Process Pattern Recognition for Building Information Models:A Case Study

Background: The fourth dimension of building information modeling (BIM) plays a significant role in construction planning by linking the construction schedule to the existing building information model. However, a difficulty may arise concerning the ease with which a link can be made and modified. Pattern-based techniques that search for recurring processes can help eliminate this drawback by producing predefined process templates. Methods: This paper critically examines the applicability of generating pre-defined process templates for BIM-based schedules using process pattern recognition techniques to reduce the effort of defining the construction schedules and integrating the templates into the BIM data. The technique estimates the level of recurrence of certain tasks within a schedule by applying several metrics. A real-life construction schedule from a housing project in the State of Kuwait was decomposed into numerous sub-schedules based on a set criterion to estimate the level of recurrence, the sub-schedules were compared based on structural and contextual similarities. Results and Discussion: The generated process templates produced demonstrated that the approach is ideal for projects with repetitive processes and that by utilizing the templates, linking building elements to tasks in 4D modeling can be greatly facilitated, thereby reducing the planning time. Conclusion: This study corroborates the results of previous literature, which found that the improvement in the efficiency of construction planning could be achieved by applying reusable process templates. The generated templates should enable the idea of storing the process templates in data banks for detecting undesired regularities in previous schedules in preparation for future use.

Performance of Composite Plate Shear Walls/Concrete Filled (C-PSW/CF) Under Fire Loading: A Numerical Investigation

Concrete-Filled Composite Plate Shear Walls (C-PSW/CF), also known as SpeedCore walls, are being increasingly used in commercial buildings due to the benefits of modularization and expedited construction schedules. This paper numerically investigates the behavior of C-PSW/CF subjected to combined gravity and fire loading. 3D non-linear inelastic finite element models of C-PSW/CF were developed and benchmarked to existing experimental data. The benchmarked models were used to understand the thermal and structural behavior of the walls under uniform fire loading, and to evaluate the effect of different parameters on the response of C-PSW/CF to combined gravity and fire loading. The parameters considered in the study were boundary conditions, wall slenderness ratio, wall thickness, axial load ratio, concrete strength, steel plate slenderness, steel reinforcement ratio, and tie bar spacing. Fire loading led to high surface (steel plate) temperatures, the evolution of non-linear thermal gradients through the cross-section, and progressive degradation of the material properties. The walls expanded longitudinally due to the thermal loads. The degradation in material properties resulted in local buckling of the steel plates between the tie bars. Continued fire exposure led to crushing/global instability failure of walls under gravity loads. The time to failure of the walls reduced considerably with a reduction in rotational fixity at the boundary conditions, reduction in wall thickness, and an increase in the wall slenderness. The steel plate slenderness of the walls should be limited to 1.2√Es/Fy to improve the time to failure of the walls. The results from this study will form a basis for the development of recommendations to estimate the fire-resistance rating and the compressive strength of the walls at elevated temperatures.

Construction Schedule Management System for Large-Scale Construction Projects Based on Multisensor Network.

As an important task of construction project management, construction schedule management is related to the realization of project period, cost, quality, and other objectives. However, in actual construction, problems such as difficulties in plan implementation and management are often encountered, and schedule delays often occur. Moreover, with the increase in the scale and complexity of modern buildings, the management of construction schedules has brought about larger issues and higher requirements have been put forward for the management level of the construction schedule. The traditional timetable management and scheduling is not highly relevant to the project entity. There is no entity change, the project information loss is serious, the tracking and control of the construction timetable is not in place, there is fine management, and the construction timetable management cannot meet the needs of modern construction. In order to ensure the smooth implementation of projects and objectives, it is urgent to explore new management ideas and methods to promote the smooth progress of construction process management. BIM technology has the advantages of visibility, simulation, adjustment, optimization, and advanced data integration, which helps to make up for the shortcomings of previous schedule management and improve the level of construction schedule management. Based on the research situation of large-scale construction project monitoring system and the analysis of information fusion technology, this paper proposes a large-scale construction project monitoring system scheme based on multisensor network information fusion. Through the investigation of the monitoring content, the composition of the multisensor network is determined. This paper is applicable to large-scale construction projects. Through the research and design of hardware modules, software modules, and fusion algorithms, the data acquisition, transmission, calculation, and display functions of the monitoring system based on multisensor network information fusion are realized, which can effectively monitor the entire process of large-scale construction projects.

The efficient generation of 4D BIM construction schedules: A case study of the Nanterre 2 CESI project in France

Building Information Modelling (BIM) can be defined as a set of tools, processes and technologies that are enabled by a digital multi-dimensional representation of the physical and functional characteristics of a built asset. The ‘fourth’ dimension (4D BIM) incorporates time-related project information in the 3D model to simulate and optimise the project construction process. To achieve this, the 3D objects within the aggregated design model must be linked with each activity in the construction schedule. However, the levels of maturity and expertise in using BIM amongst the project participants still varies considerably. This generates collaboration problems within the project and adds further obstacles to the ability to derive full benefits from BIM. Ideally, 4D BIM can be automatically generated, but in reality, because the 3D and 4D models are created separately and at different stages of the project, this is not currently possible, and the process requires considerable manual effort. The research reported in this paper was prompted by the construction of a new training and research building: the Nanterre 2 CESI building in France. It proposes an efficient approach that minimises the effort of creating 4D BIM construction schedules. The CESI four-phase process aims to help project participants to fully exploit the potential of 4D BIM and enables: 1) a clear expression of the 4D BIM objectives; 2) the identification of information requirements and relevant workflows to achieve these objectives; 3) the implementation of a project schedule; and 4) BIM model production to suit the 4D BIM use case. Although the CESI approach was developed in the context of the French contracting system, the observations and conclusions of this study are intended to be generally applicable.

A Bayesian-driven Monte Carlo approach for managing construction schedule risks of infrastructures under uncertainty

The construction of infrastructures has often been challenged by construction delays, which are disruptive and expensive. As the construction of infrastructures is more complex and riskier under uncertainty, the construction schedule risks are becoming more interconnected and occurring in a chain of cascading events in practice. However, past research typically ignored the interdependency between sequence of risk occurrence (e.g., chronological and causal relationships). This research aims to close this gap through developing a novel approach based on Bayesian-driven Monte Carlo (BDMC) simulation for managing these interdependent construction schedule risks of infrastructures under uncertainty. This approach integrates hybrid data processing and analytics methods to (1) construct Bayesian network for identifying risks and risk interdependencies (i.e., causal relationships), (2) conduct risk inference and construction duration prediction involving both of chronological and causal relationships between risks, and (3) identify critical and sensitive risks and provide the most appropriate strategy for risk mitigation. The approach firstly pre-processes the data from risks and risk interdependencies to construct the risk network. It further constructs the Bayesian network using deep-first search (DFS), adapted maximum-weight spanning tree (A-MWST) algorithms and leaky-MAX model. Then the approach is developed for risk mapping based on BDMC simulation and for risk mitigation based on sensitivity and scenario analysis. Finally, a real infrastructure project is selected as the case study to verify this developed approach. Compared to conventional methods, the results show that the developed approach can provide more accurate schedule prediction with least 0.166% error ratio through incorporating interdependent risks into schedule prediction. It is also more informative through proposing effective risk mitigation strategies for delay avoidance and uncertainty reduction, and more convenient in data acquisition and processing when developing a Bayesian network through the developed hybrid data transformation approach converting the risk network into Bayesian network. This research contributes a new way to understand and analyse the interdependencies of risks and their impacts on construction schedule. The developed approach can be beneficial to managing construction schedule risks of infrastructures under uncertainty.

A pre-assessment and pollution prevention tool for indoor volatile organic compound simulations during the interior design stage

Volatile organic compounds (VOCs) are common indoor pollutants that can deteriorate indoor air quality. The pre-assessment of VOC concentrations aimed at pollution prevention during the interior design stage is effective in terms of time and expense for VOC control, as required by engineering applications. In this study, we introduce the concept, framework, and mathematical models of a pre-assessment and pollution prevention tool for VOC simulations. This tool considers multiple emissions sources and sinks, the interior construction schedule for the building materials, internal and external airflows, and air cleaning. The emissions/adsorption patterns from building materials were numerically coupled with the combined effects of the thermal environment, ventilation, indoor VOC concentrations, and emissions/adsorption from other materials at each time step, thereby improving the accuracy of the tool in engineering applications. The proposed tool was applied in an office building with multiple rooms and building materials to illustrate the simulation procedures and validate its effectiveness at VOC preventive control. The main emissions sources were determined and the selection of building materials was modified based on the simulation results. Field measurements were performed and the measured data were compared with the simulation results after construction completion. Differences between the simulated and measured results were predominantly within 0.02 mg/m3. The normalized mean square error was 0.11 and the mean relative standard deviation was 16.9%. This method can be used for indoor VOC concentration estimations, source contribution analysis, interior design scheme optimization, and ventilation rate requirement estimation, among other applications.

In-situ methods for the TBM dismantling in a long-distance and deep-buried tunnel: Case study of Xinjiang water conveyance tunnel

With the rapid development of traffic, water conservancy and energy exploitation, more and more tunnels are excavated by tunnel boring machines (TBMs) in the world. Some of these tunnels trend to be long-distance and deep-buried. Given the construction schedule and cost for a project, two or more TBMs are frequently used at the same time in the project. In these projects, the TBMs have to be dismantled in the tunnel after the expected tunnelling work is finished. The dismantling method determines the construction schedule, cost, and the residual value of the TBM. Thus, it is critically important to provide the proper in-situ methods for the TBM dismantling in long-distance and deep-buried tunnel. In the present study, potential in-situ methods for the TBM dismantling are studied based on a water conveyance project in Xinjiang province, Northwest China. Firstly, the engineering background about the project is briefly presented. Then the potential in-situ methods for the TBM dismantling are illustrated. These methods are provided for the main engine disassembling and the subsequent supporting system disassembling. The factors that affect the selection of the dismantling method are discussed. All the methods for the TBM dismantling are comprehensively compared. Finally, the optimal in-situ method (“dismantling + burying” method) is recommended for the Xinjiang water conveyance project. With the increasing use of multiple TBMs in long-distance and deep-buried tunnel construction, the experiences accumulated and lessons learned from this TBM-excavated tunnel can provide good references for similar projects.

MITIGATION OF ADDITIONAL OVERDESIGN IN PORTLAND CEMENT CONCRETE BY OPTIMIZING THE CEMENTITIOUS MATERIALS CONTENT

More cement does not necessarily make better concrete or expedite construction schedules. In contrast, concrete with lower cementitious content can reach sufficient strength on time to avoid construction delays and last longer. Standard specifications require concrete overdesign (OD) for decades, but studies assessing the actual OD magnitudes are rare. This experimental study aimed to identify the required cementitious materials content (RCC) to meet the OD based on 958 compressive strength tests (σ) representing 8200 m3 of ready-mixed concrete for threshold buildings. The actual OD in commercial concrete appears to be 7 to 21% higher than required. The cementitious materials content should be reduced between 6 and 17% so that concrete can reach the required compressive strength (f’cr) without cement overconsumption. The additional overdesign (AOD) increased significantly as the specified compressive strength (f’c) increased, indicating that concrete producers can be more cautious when the f’cr is higher. Further research is needed to expand the range of cementitious contents and applications.

Time-space modelling of construction

A successful construction project respect the construction time and the estimated costs. Such a smooth construction process ensure effective scheduling. A good time construction plan can be a daunting task for a construction contractor. The article deals with time scheduling of line construction in TILOS software. The result is an analysis of scheduling in this software. The advantages and disadvantages of working of modelling a time-distance graph are described. For better control, it is very advantageous to have a well-processed schedule, which will be to the building model by various logical links connected. Thanks to this compound, it is possible to model the building of construction in the shortest possible time and as smoothly as possible. In conclusion, it is stated, that a well-crafted time construction plan can point to possible construction collisions. An updated time-distance graph processed in a software environment can reveal construction risks and the needed rescheduling in a timely manner. Therefore, it is possible to meet the scheduled construction time and estimated costs.

Tools of 4D modeling of construction projects

The 4D BIM model links the construction schedule and the 3D construction model. The 4D model makes possible to visualize how the construction and its structures in the construction site would look like at any point in time by simulation the construction process. The article provides basic information about BIM technology and 4D modeling. Various levels of tools for creating 4D models are presented in the core of the article. The analysis of selected software from the point of view of their conformity with requirements for creation and for usage of 4D models in construction practice is processed.

A Heuristic for the Two-Echelon Multi-Period Multi-Product Location–Inventory Problem with Partial Facility Closing and Reopening

In this paper, the two-echelon multi-period multi-product location–inventory problem with partial facility closing and reopening is studied. For each product and period, plants serve warehouses, which serve consolidation hubs, which service customers with independent, normally distributed demands. The schedule of construction, temporary partial closing, and reopening of modular capacities of facilities, the continuous-review inventory control policies at warehouses, the allocation of customer demands to hubs, and the allocation of hubs to warehouses are determined. The service levels for stockout at warehouses during lead time and the violation of warehouse and hub capacities are explicitly considered. The proposed mixed-integer non-linear program minimizes the weighted summation of the number of different facilities and logistical costs, so that the number of different facilities can be controlled. Since the proposed model is np-hard, the multi-start construction and tabu search improvement heuristic (MS-CTSIH) with two improvement strategies and the modified MS-CTSIH incorporating both strategies are proposed. The experiment shows that the two improvement strategies appear non-dominated, and the modified MS-CTSIH yields the best results. The comparison of the modified MS-CTSIH and a commercial solver on a small instance shows the efficiency and effectiveness of the modified MS-CTSIH. The sensitivity analyses of problem parameters are performed on a large instance.

Understanding GIS in visualization and evaluation of construction schedule

Economically successful available scheduling tools such as Primavera and Microsoft Project fail to provide information about the geographical aspects of a construction project. A methodology using geographical information systems (GIS) is developed to represent the geographical aspects of the construction progress graphically by accompanying and linking it with the construction schedule. The spatial or geographical aspects are illustrated by the 3D model developed in AutoCAD and the construction schedule is generated via MS Excel sheets and linking it to ArcVIEW. Spatial and scheduling information are linked together into the GIS environment (ArcGIS) With a GIS, we can identify and analyze the land features, climate, boundaries, population, resources, and many other things about places that interest you. In the past, you needed to use paper maps, globes, and a variety of hard-copy data sources to perform these analyses. The main purpose of the research is to discover a simple and perceptive way of assigning the essential project information from a constructional CAD model to scheduling software and streamlining sequencing and organizing project activities. In achieving this goal, one of the most exhausting and time-consuming steps in producing a construction project schedule will be removed. By the end of this project, we will be able to understand the GIS system, and how to visualize it while scheduling the project and its uses. Keywords- Geographical Information System, spatial information, scheduling, visualization

Automatic generation of BIM-based construction schedule: combining an ontology constraint rule and a genetic algorithm

PurposeThe purpose of this study is to automatically generate a construction schedule by extracting data from the BIM (Building Information Modeling) model and combining an ontology constraint rule and a genetic algorithm (GA).Design/methodology/approachThis study developed a feasible multi-phase framework to generate the construction schedule automatically through extracting information from the BIM, utilizing the ontology constraint rule to demonstrate the relationships between all the components and finally using the GA to generate the construction schedule.FindingsTo present the functionality of the framework, a prototype case is adopted to show the whole procedure, and the results show that the scheme designed in this study can quickly generate the schedule and ensure that it can satisfy the requirements of logical constraints and time parameter constraints.Practical implicationsA proper utilization of conceptual framework can contribute to the automatic generation of construction schedules and significantly reduce manual errors in the Architectural, Engineering, and Construction (AEC) industry. Moreover, a scheme of BIM-based ontology and GA for construction schedule generation may reduce additional manual work and improve schedule management performance.Social implicationsThe hybrid approach combines the ontology constraint rule and GA proposed in this study, and it is an effective attempt to generate the construction schedule, which provides a direct indicator for the schedule control of the project.Originality/valueIn this study, the data application process of the BIM model is divided into four modules: extraction, processing, optimization, and output. The key technologies including secondary development, ontology theory, and GA are introduced to develop a multi-phase framework for the automatic generation of the construction schedule and to realize the schedule prediction under logical constraints and duration interference.