Chang-Yeon Cho

SIMULATION METHOD OF CONSTRUCTION HOIST OPERATING PLAN FOR HIGH RISE BUILDINGS CONSIDERING LIFTING HEIGHTS AND LOADS

Lifting indicates vertical transfer of construction resources. In high-rise building, efficient plan and management on lifting of resources are ess ential because of enormous impact on schedule, and amount of resources and data. In part icular, a hoist—one of main lifting equipment for workers and construction materials—may have direct influence on overall project schedule depending on its number, location and operation method. To ensure efficient construction, it is critical to have an optimal hoi st operating plan. Engineers depend on various empirical methods, which have been optimized through numerous feedbacks from construction projects. Therefore, it is necessary t o optimize hoist plan and management based on both engineers’ experiences and simulation based on actual data on lifting load and height. This paper describes a simulation method to provide data to an experienced engineer for accurate decision-making.

An Algorithm for Hoisting Time Calculation in Super-tall Building Construction

An installation of the construction lift has a few limitations by many constrains and these have influences on labor productivity, that can be changed by vertical-transportation management. In the super-tall building construction, a management of construction lift operation is one of the most important factor, but existing methodologies depend on skilled practitioners` experiences. And it is true that the expertise resulted by the experiences does not transfer to the next generation. This study is a part of lifting-management simulation development which aims at the optimal construction lift management. A proposed algorithm is focus on lifting time calculation considering an acceleration capability. This research evaluates the result accuracy using comparative analysis on simulation result and field measuring time.

Basic Study of Smart Robotic Construction Lift For Increasing Resource Lifting Efficiency in High-Rise Building Construction

Most high-rise buildings are erected in downtown areas, where on-site storage space for construction materials is typically insufficient due to limited spaces. Just-In-Time (or JIT) concept has been adopted so that necessary stock materials and storage spaces can be reduced; for high-rise buildings, however, transporting materials vertically using lifts still poses significant efficiency because its efficiency drops exponentially as the building height grows. Most of current efforts to counter this problem mainly focus on developing smart tower cranes, whereas lift has gathered less attention in this respect. This research aims to develop a robotic lift capable of autonomous operations at night time, based on the intelligent lift development toolkit which was previously developed by the authors. It is now in a preliminary study phase. This study proposes a concept model of the robotic lift system and its operation plans, utilizing several technologies such as an optimized material dispatch algorithm and ubiquitous sensor networks (USNs). The proposed system can be relayed to the horizontal transportation robots located in each floor to move the lifted materials to their destinations. The outcome from this study will contribute to the improvement of the overall efficiency of the high-rise building construction logistics and space constraints of the construction site. It is also expected that the mechanical performance of the existing lift system can be benefited from this research. When overall system development, including optimized operation planning model and monitoring subsystem, is finished, it will contribute to innovation of the construction technology.

A Development of 3D Image Data Merging Module for Intelligent Excavation System

This research is a part of Intelligent Excavation System (IES) Development Project which aims the autonomous excavator for earthwork. The developed module focuses on measuring real-time productivity for Task Planning System(TPS) of the IES. This module merges 3D data obtained using two different 3D imaging systems : The 3D laser scanner ; and the stereo vision system. Real-time productivity of IES is calculated automatically. Once point cloud data is acquired by the 3D scanner, it is converted into mesh surface. Some post processing such as mesh optimization (reduce slenderness) and noise filtering are performed. Point cloud data is also acquired by the stereo vision, which is installed on the top of the cabin of the IES. Teo different 3D surface data are merged by the automatic fitting and smoothing algorithm. Excavated earth volume changes are recognized during the merging process. This research evaluates the performance of the merging algorithm using the real data from the civil earthwork site.

An Optimatl Algorithm of The Multi-Lifting Operation for Super-Tall Building

The operation and management plan for a lift, an important factor determining work productivity on a highrise building construction site, has long been considered to be less significant than those for a tower crane, which has resulted in a lack of studies of systematic operation planning for lift. Due to various restrictions on high-rise construction sites, only a small number of lifts can be installed. The restrictions on the installation of lifts have a great influence on labor productivity by floor, which can be changed by the management of the vertical movement of the lifts. Improving the work efficiency of lifts at a construction site is evaluated as an essential management factor to improve labor efficiency on each floor; on the other hand, the efficient management of such lifts is dependent on experienced workers. Considering this, as part of a simulation development for the work efficiency of lifts, one of the major factors in a high-rise building construction, this research aims to develop an algorithm to predict and operate the optimal lift operation time, when two or more lifts are simultaneously operated, based on the work efficiency time calculation algorithm, and to present the optimal operation expectation of the lift in a quantitative way. In the future, the algorithm developed in this research will be equipped in a module to predict and evaluate the work efficiency of a lift in an intelligent work efficiency management system.

Prediction Model for Hoisting Time Using Luffing-Type Crane for High-Rise Building Construction

Hoisting planning for systematic and efficient vertical transportation is one of the key factors for successful completion in high-rise building construction. However, despite this importance, minimal research has been carried out for predicting hoist time, which is a key player in hoisting planning. Therefore, this study proposed a prediction model for vertical hoisting time using a luffing-type crane. From the results, validation of the model showed the potentiality to apply the actual prediction of hoisting time of a luffing-type crane after additional research.

A Study on Development of the Automated Vertical Controllable Pilot-Type Equipment for PHC Piles

This research is intended to develop a pilot type of automated pile verticality control equipment for PHC piles and motivated by a desire to address problems inherent in as-is verticality control exercise during pile driving. The paper provides understanding of the current verticality control methods and associated problems, design and manufacturing of the automated equipment pilot type, its testing and discussions of the results.