Study On Calculation Methods Of Reinforcement Cage Hoisting Of Super-deep Diaphragm Wall

With the development of social productivity, there are more and more large deep foundation pit engineering.Technology of underground continuous wall is widely used in the underground structure construction, the use of diaphragm wall is the safest and most reliable form in supporting forms of deep foundation pit, and reinforcement cage hoisting, as one of the most important aspects of the wall construction technology, has very important influence in the construction of the underground continuous wall. With the promotion of ultra deep diaphragm wall technology, the wall reinforcing cage hoisting technology will be widely used.The usual method of reinforcing cage hoisting of deep diaphragm wall is “built in sections,hoisted in the case,split connection”, the method has high security, but its disadvantages are low efficiency, high cost, the welding quality can not guaranteed, and the perpendicularity is not easy to control after welding. In modern construction site, the approach of assembly disposable hoisting has been increasingly used basing on large and advanced lifting technology. The approach has good entirety, short construction period,high efficiency and low cost, but the assembly hoisting of reinforcement cage has its particularity because the reinforcement cage itself has big quality, long length, low stiffness and high local stress at the cage body lifting point. If the lifting point is not been reasonably set and the reinforcement measures dose not in place in the process of hoisting, the reinforcing cage may has big vertical deformation, it is the head and tail of the cage is lifted off the ground, but he middle of cage is still on the platform. Quality safety accident such as cage apart may happen if forcibly hoist the reinforcing cage. At the same time, the stress of the reinforcing cage in hoisting is big different form the stress in to the wall. Therefore, the corresponding hoisting analysis and design research is very necessary.Basing on the construction technology of the diaphragm wall and the existing related research, the paper analyze the mechanical performance of the diaphragm wall reinforcing cage to study the role of the longitudinal, transverse and diagonal web reinforcement bars though establishing the finite element model of the diaphragm wall reinforcing cage of a main center tower.At the same time, though deducing the formula of force in the hoisting point and wire rope in the condition of hoisting deviation may appeared in the process of reinforcing cage hoisting to study the effect of the deviation of hoisting.In addition, some optimization suggestions on the set of the web reinforcement of the reinforcing cage are given through establishing the finite element model of ladder and triangle abdominal frame and comparing the mechanical performance of the abdominal frame. Basing on the study of the mechanical performance of the diaphragm wall reinforcing cage to simplify the spatial structure to combination abdominal frame structure; Though analyzing the characteristics of the combination abdominal frame and choosing analysise model to simplify the combination abdominal frame to planar abdominal frame; In addition,though analyzing the characteristics of the planar abdominal frame and choosing analysise model to simplify the planar abdominal frame to one-dimensional truss structure.