The Safety Supervision Research of Construction about Foundation Design and Installation and Removal of Tower Crane
|School||South China University of Technology|
|Course||Architecture and Civil Engineering|
|Keywords||tower cranes (tower crane) foundation design installation and removal (the demolition) construction safety supervision|
In recent years, by the rapid development of high-rise building construction, major high-rise tower is widely used in the main construction as vertical transport machinery. As the foundation design of tower crane and the installation and removal of special construction involves structural load value, groundwork and foundation, reinforced concrete structure, steel structure, high-rise structures, construction machinery, construction management, equipment testing, project supervision, and many other professions, whose technical content is high, installation and removal process is more complex, and there will be seriously social impact and economic consequences if security incidents happened. For the current security issues of tower crane, this paper analyzed the causes of tower crane accidents with some cases, and summarized the hidden problems and solutions of tower crane accidents.Firstly, during the foundation design, the main problem is that there are deviations in parameter values when calculate the load M、、,which the tower crane passes to the top surface of foundation, for instance, the basic wind pressure , wind vibration coefficientFv Fhw0βz, shape factor and wind pressure equivalent highly variable coefficient is not considered combining the location of the project, there are some bias or error in calculations, causing the level of load calculation errors. In addition, there will be bias calculating load if the parameter used is not based on the type of tower crane. On the other hand, the lack of the tower crane foundation geological survey report, the foundation bearing capacity values reference data adjacent to the project, but also to bring the security of the foundation design bias. usuz FhfakFoundation area selection of tower crane should consider site conditions, geological conditions, load size, building planes, construction, construction cost and construction safety and other factors comprehensively. The reality is that the using unit or tower crane installed units often do not consider the above factors, select the form the basis blindly, leading to a waste and conservative foundation design, or the fact that anti-overturning stability, foundation bearing capacity or anti-punching can not meet the requirements, which is a security risk. In the process of specific foundation design, for the different foundation types, based security index system is not exactly the same. According to the author’s experience in the review of the tower crane foundation, the basis of the current large number of tower crane safety indicators confusion, lack of uniform standards.For the above situation, this paper presents a relatively complete system of the tower crane foundation design system, details the parameters of tower crane, load calculations, foundation bearing capacity calculations, foundation reinforcement cross-section calculation, basic punching checking, basic stability against overturning checking formulas and allowable values of indicators, with a concise, focused and guidance to facilitate the use of tower crane units and supervision of institutions in program design and review of tower crane, there is a reference to the calculation of indicators.Second, the tower crane installation and removal, the security issues highlighted in the unit without the demolition of tower crane tower crane safety and demolition qualifications, no induction of trained special operations personnel, no tower crane installation and removal program, the phenomenon of higher risk operations, a large number of accidents occurred in the tower crane installation, jacking and removal process. In view of this administration, this paper pointed out that the law enforcement inspection system set up special equipment, to increase removal of the tower crane business intelligence review and set up a tower crane safety and the demolition companies demolition program project filing system, the demolition of no special construction tower crane demolition of tower crane safety program units for punishment and notification. While strengthening the demolition of tower crane safety and special operations units in the training of staff posts and dynamic sampling personnel transaction conditions to ensure the installation and removal operations personnel trained in special operations staff posts, from human resources to ensure the installation and dismantling of tower crane safety operations .Third, in the special equipment information management, tower crane, the current tower on the market yet to establish a local file filing system, leading to the factory after a tower crane and construction site into the rental market follow-up information can not be tracked, such as tower crane extended active duty, breach repair , illegal modification, such as the old charge of new information security risks can not be recorded, and these risks lead to tower crane accidents are the direct cause. In view of this, the paper pointed out that the special equipment supervision and management departments should establish a filing system files tower, tower crane into the market straight after recording all the information. Special equipment supervision and management departments should regularly checks the site tower crane used in the information file, the file was created for non-unit tower ownership impose severe penalties, by the tower crane tower crane ownership units go through the file for the record!Fourth, the tower crane use and maintenance, there is induction of non-special operations personnel to act as drivers, rigging, and signal work, illegal work, illegal command, illegal use, great security risk. To reverse this situation, this paper proposes to strengthen the tower crane use special operations unit staff induction training and examination, appointment of special operations personnel are not complete units of tower crane use of economic sanctions or administrative notification, order the suspension rectification.Fifth, in the tower crane construction safety supervision, the current widespread use of unit supervisors submit the tower crane foundation design and installation and removal of construction plan review, qualitative language to describe a mere formality, especially for the lack of the tower crane foundation design quantitative calculation basis. This shows the ability of supervision of professional engineers need to improve on the other hand, the lack of a system supervising engineer of the tower crane construction safety supervision guidance document. In this paper, the implementation of the status quo of the construction of tower crane safety expert verification system supervision program, after five or more singular expert verification of the program can use the unit reported to the supervision by the unit approval. Meanwhile, this paper aims to complete construction of a system of tower crane safety supervision guidance documents, supervision of projects to increase business training, guidance rules to follow to carry out the supervising engineer of construction tower crane safety program review.Based on the analysis of the five issues and case studies demonstrating above, the conclusions and recommendations of the subject researched are summarized. Through the practice and empirical analysis by project supervision, the subject researched show its main benefits: Firstly, the cost-effectiveness. To avoid the tower crane collapsed, folded arms, falling objects, etc. which will lead to serious injuries and deaths accidents, according to three people per accident casualties, 420,000 Yuan per person for medical expenses and compensation for pension calculation, saving 3×42 = 126 million Yuan, and maintenance costs of tower itself, about 50,000 Yuan, namely, the direct costs of security incidents, about 131 million Yuan, is to avoid. During the investigation of accidents, the site also lay-off, each man-day cost about 100 Yuan; a tower crane impact steel benders, carpenters, concrete workers by 50 per day, the loss of work stoppage is 50×100 = 5000 Yuan; tower crane rental fee for each class is about 1,000 Yuan. The daily lay-off fees and tower crane rental fee of 6,000 Yuan, according to which only 50 and a tower crane is considered, and the work stoppage caused schedule delays caused by loss of management fees and penalties is not considered.Secondly, in the social effect. To avoid the tower crane accidents, safeguard people life and property safety, is conducive to family happiness and social harmony.