• Journal of the Korea Institute of Construction Safety
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• v.6 no.1
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• pp.7-11
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• 2024

Pump car is an equipment that transports concrete products as needed to the place where they are poured. In order to pour a large amount of concrete in a short period of time, using a pump car is the most efficient in terms of economic efficiency and quality control. However, recently, many casualties have occurred due to boom damage during concrete pouring, so this study suggests that improvements are needed in the equipment manufacturing stage, inspection standards for old equipment, and equipment rental system. The reason is that, as a result of the finite element analysis of the pump car, the significant stress acting at the second stage of the boom and the maximum stress at the top of the boom were found to be 895.39 MPa, and M.S. Since it was evaluated the lowest at 0.04, the need for reinforcement was recognized. And it was confirmed that the 2nd stage boom was the most stressful and vulnerable part of the 1st to 5th stage booms. Therefore, it is necessary to increase the thickness and rigidity of members at the design and manufacturing stage, and to reinforce the steel plates of currently used equipment. In addition, it is urgent to establish a system that makes non-destructive testing mandatory for all general construction machinery and holds inspection agencies responsible for missing boom defects during non-destructive testing and regular inspections.

• Journal of the Korea Institute of Construction Safety
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• v.1 no.1
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• pp.47-56
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• 2018

In this paper, we analyze various cases of accidents caused by vehicle-mounted MEWPs(mobile elevated work platforms) which are most widely used for the high position level works, review the safety improvement measures for each of them, and propose basic data for the revision of related laws. The accidents by MEWPs were caused by the high level of works, which lead to fatal personnel accidents, so the measures for safety must be thoroughly carried out and the obligatory regulations by the related laws must be strictly observed. In this paper, we classify the cases of accidents at the workshop as 4 representative types and propose measures and remedies for them. According to the current regulations, it is possible to prepare for the accidents such as the wire rope breakage by switching to the all-chain drive method which does not have a daily use time limit instead of the wire rope drive method which is widely used at present. Also, it is suggested to add the daily use timetable to the nameplate attachment duty item according to the driving class.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.12
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• pp.1901-1907
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• 2010

A hydraulic cylinder is a primary component of an excavator and is used for activating attachments such as boom, arm, and bucket. Generally, the cylinder is prone to structural problems such as buckling and fatigue failure caused by cyclic high pressure. Therefore, the safety margin for fatigue, yield, and buckling during the design lifetime should be evaluated at the durability-design stage. The durability design includes basic and detailed stages. In the basic design, the principal dimensions of the rod and tube are determined by considering the working force, speed, and range with respect to yield and buckling. In the detailed design, the dimensions of the rod notch, welds, tube end, gland, orifice, and cushion ring are determined by considering the fatigue safety. We present and discuss the overall procedure for durability design and the related analysis techniques.