Automatic data processing system for integrated cost and schedule control of excavation works in NATM tunnels

A type-based system is widely used for cost and schedule control in the NATM (New Austrian Tunnelling Method) tunnel. This study raises several limitations of the type-based system: a broad level of control, a distributed approach to cost and schedule data, ad hoc management, and difficulty in deriving meaningful data. Integrated cost and schedule control promises a myriad of benefits on both information flow and construction management. Nevertheless, the integrated approach still seems to be a long way from common use in the construction industry because it requires considerable overhead effort to acquire, track, and analyze the integrated data. The objective of this study is to propose a new method to automate the required processes for implementing cost and schedule integration. We propose an operational-level automatic data processing system for cost and schedule integration. The proposed system consists of a real-time location system for detecting equipment locations, a wireless mesh network for transmitting the location signals to a field office, and a prototype model for transforming the signals to cost and schedule data. Technical feasibility is analyzed through a pilot project. The study offers a new approach to facilitating sensor technologies for cost and schedule integration

Development of an advanced composite system form for constructability improvement through a Design for Six Sigma process

System form is widely used when constructing concrete buildings and structures because it has high productivity and good concrete casting quality compared with traditional hand-set form. However, from a worker’s perspective, system form is still very harsh to handle because of its heavy weight, noise generation, and use of releasing agent, and it also attenuates the productivity of system formwork. Therefore, this study proposes the use of an advanced composite material-based concrete form for workers using a Design for Six Sigma (DFSS) process to improve constructability of system formwork. User requirements are systematically reflected in the technical characteristics of concrete form, and innovative principles are scientifically organized through the DFSS process that mainly consists of quality function deployment and theory of creative problem-solving methods. The proposed composite form showed improved performance in deriving high-quality formwork and worker-friendly working conditions compared with previous system forms. Additionally, this study demonstrated how the DFSS will be a valuable tool for technology development and systematic decision-making in building construction

Economic Analysis of USN-Based Data Acquisition Systems in Tall Building Construction

The successful construction of tall buildings requires effective construction management based on various quantitative data. The recent development of ubiquitous sensor networks (USNs) enables massive amounts of data to be collected in real-time. However, the application of USN-based data acquisition systems to repetitive tasks on typical floors of tall buildings can be inefficient, because this may involve the repetitive reinstallation of sensors and the repositioning of data loggers and routers to enable continuous data transfer. To minimize this cumbersome work, a modified data acquisition method using reusable sensor nodes and mobile devices can be a useful solution. This study analyzes the economic aspects of the USN-based systems for concrete temperature monitoring by using the activity-based costing technique. The case study shows that the modified system can reduce the process cost by about 19%. It can also reduce the resource input time of management by about 55%, freeing up time for other management activities. Moreover, the cost benefits should scale up as projects increasingly require more measurement and monitoring. This study should facilitate the application of USN-based information management systems, particularly for tall building construction

Detailed Activity-Based Earthwork Scheduling Model to Aid during the Planning Stage of Road Construction

Earthwork scheduling (during the planning phase of road construction) is an important task that directly affects the cost and time of a project. However, the current scheduling methods are not performed at a detailed level and carry forward gaps from the actual schedule in the construction stage, causing problems, including time delays and additional costs, during the construction stage and thereby leading to the modification and supplementation of existing plans. Many studies related to scheduling have focused on process optimization or automation; therefore, the gaps between the planning and construction stages have not been studied well. These gaps must be determined in advance to solve the fundamental problem of earthwork scheduling in road construction. Therefore, this study proposes a detailed activity-based scheduling model for earthwork at the planning stage to minimize the gap between the planned schedule and the actual process at the construction stage. The proposed model comprises a detailed activity-based database of earthwork in road construction (DADER), which enables the subdivision of the existing earthwork schedule plan, and a dynamic programming (DP) procedure, which enables the combination of activities. The earthwork schedule at the case site, planned for only three activities, is subdivided using DADER into 36 activities. Additionally, the DP procedure is used to derive a combination of activity alternatives that minimizes the cost among the conditions that satisfied the input target duration. The model is verified through an expert survey using a 7-point Likert scale. Results show that the model has cost efficiency (4.19), onsite applicability (4.70), and task efficiency (4.48). The findings indicate that performing scheduling during the planning stage of earthwork projects can help reduce additional work caused by the gap between the site and the plan. This study will help improve the productivity of road construction projects by providing correct process optimization and automation research data

Simulation Model for Productivity Analysis of External Insulated Precast Concrete Wall System

External Insulation Finishing System (EIFS) is recognized as a suitable method for attaining energy efficiency of buildings. However, conventional EIFS is not actively applied to building construction due to additional time and cost compared with interior insulation method. Therefore, as an alternative that can contribute to active utilization of the external insulation system, this study proposes an External Insulated Precast Concrete (PC) Wall System and its simulation for performing productivity analysis. Results of this study are as follows: (1) an external insulated PC-Wall system is developed of which its insulation performance is above 40% higher than that of the conventional EIFS; (2) performance of the developed system satisfied American Standards for Testing of Materials (ASTM) and American Architectural Manufacturers Association (AAMA) standards; (3) applicability of the developed system is verified via test-bed with construction time lapsing about 40 min for each PC-Wall; and (4) CYCLONE modeling methodology is employed to perform productivity analysis of the developed system compared with conventional EIFS

Building Component Detection on Unstructured 3D Indoor Point Clouds Using RANSAC-Based Region Growing

With the advancement of light detection and ranging (LiDAR) technology, the mobile laser scanner (MLS) has been regarded as an important technology to collect geometric representations of the indoor environment. In particular, methods for detecting indoor objects from indoor point cloud data (PCD) captured through MLS have thus far been developed based on the trajectory of MLS. However, the existing methods have a limitation on applying to an indoor environment where the building components made by concrete impede obtaining the information of trajectory. Thus, this study aims to propose a building component detection algorithm for MLS-based indoor PCD without trajectory using random sample consensus (RANSAC)-based region growth. The proposed algorithm used the RANSAC and region growing to overcome the low accuracy and uniformity of MLS caused by the movement of LiDAR. This study ensures over 90% precision, recall, and proper segmentation rate of building component detection by testing the algorithm using the indoor PCD. The result of the case study shows that the proposed algorithm opens the possibility of accurately detecting interior objects from indoor PCD without trajectory information of MLS

Simultaneous Localization and Mapping Algorithm for Topological Maps with Dynamics

A simultaneous localisation and mapping (SLAM) algorithm for topological maps is proposed. Especially, this algorithm deals with a semi-permanent dynamics induced by door opening and closing. To deal with the semi-permanent dynamics, nodes are classified into two types. One is an invariant node that is free from the dynamics, and the other is a variant node that is not affected by door opening and closing. Two different approaches are used at the same time: a quasi-static SLAM for the invariant nodes and a dynamic SLAM for the variant nodes. A gross shape of the given environment is represented by the quasi-static SLAM algorithm, and a detailed shape of the environment is revealed via the dynamic SLAM. Experimental results validate that the proposed algorithm produces a topologically consistent map under the semi-permanent dynamics.X1147sciescopu

Exploring research trends and network characteristics in construction automation and robotics based on keyword network analysis

Over the past decades, automation and robotics have been widely adopted in the construction industry as a promising solution for troubleshooting issues. This field is highly interdisciplinary and rapidly changing, and new concepts and ideas are being actively introduced in association with the existing ones. To reveal new insights, the evolution of knowledge in this field needs to be characterized by identifying important knowledge elements and research trends from published data. This study investigated research trends and network characteristics in the field of construction automation and robotics by using a keyword network analysis based on published articles. We analyzed the structure of the keyword network and identified major research topics and their relationships. Notable findings of the research characteristics are as follows. 1) Popular research themes with a set of closely connected keywords continue to be selected and contribute to the evolution of the network. 2) As an interdisciplinary research area, popular keywords that actively interact with other keywords also bridge different clusters of related research concepts. This study could provide useful insights and a better understanding of the knowledge structure and research trends as well as information on future directions in the construction automation and robotics field

Assessment of Delay Factors for Structural Frameworks in Free-form Tall Buildings Using the FMEA

Abstract There are many factors in a common building project that are not relevant for free-form tall building projects, for example, the free-form planes or various shapes of buildings. Among the many risks present in particular in structural frameworks, the risk of delays is an important one and has a considerable effect on the entire project performance. Generally, a delay causes a decrease in constructability and an increase in cost, so eventually the productibility of the structural framework would decrease. Delay management of structural frameworks in free-form tall buildings is currently performed by project managers based on personal experience and intuition. This nonsystematic management results from the lack of data that are essential for the planning construction process reflected in the particular considerations of the free-form tall building. This study identified the delay factors that can occur in the structural framework of free-form tall building projects and analyzed priorities for delay management. First, the scope of free-form tall buildings was identified, and particular considerations for the structural framework in their construction were determined, such as plane, elevation, floor height, and structure. Delay factors for each category were recognized through interviews with experts with experience in such projects. To prioritize the delay factors, the occurrence and severity of each factor were surveyed. A risk priority number was calculated from the survey results, and the priority was analyzed. The results of this study could serve as preliminary data for the planning construction process of structural frameworks in free-form tall buildings