Technical Research On Safety Assessment Of Existing Building Tower Cranes

With the rapid development of construction industry, tower crane, as special equipment for vertical transport commonly used in high-rise buildings and construction, is being used more and more widely. Meanwhile, all kinds of accidents occur more and more often with the increasing number of tower cranes being used. Safety assessment aims at the system security in practice, conducting qualitative analysis and quantitative calculation on risk factors in the system, the possibility of accidents as well as the loss and damage degree, so as to provide scientific basis for the safety of the evaluated system and formulating basic precaution and protection. Therefore, carrying out the study of safety assessment of tower crane is of great theoretical significance and engineering value.With cooperation with Liaoning Academy of Safety Science, on the basis of existing research, FMEA analysis table of general tower crane is established, FMEA analysis of tower crane is completed, and all the failure modes and failure reasons of general rotary tower crane are obtained. With reference to risk-based inspection (RBI) technology and combination with the structure characteristics of tower crane as well as traditional examination standards, a safety evaluation system based on RBI technology of tower crane in service is established. It gives the method of qualitative analysis on risk for tower crane parts, formulates the evaluation criteria of the possibility and consequence of failure, and completes the qualitative risk assessment of 50 parts of general rotary tower crane; it also establishes the quantitative calculation model of risks for tower crane parts, presents the computing method of the actual failure probability, sets up the evaluation standard of relevant correction factor, improves the quantitative evaluation method of failure consequence, and provides a standardized and programmed evaluation procedures and criteria for quantitative calculation of risk. According to the theoretical study of safety assessment of tower crane, based on VB platform and ACCESS database, safety assessment software system of tower crane is programmed. With this software, technical personnel can automatically complete the risk assessment of all parts of a tower crane, save the corresponding information, and output assessment report according to user’s needs.This paper presents safety assessment of tower crane in service, formulates qualitative and quantitative evaluation criteria of risk from crane parts, programs safety assessment system software and provides reference value for safety assessment and accident prevention of tower crane.