Technology And Engineering Application Of Long Span Composite Of Vierendeel Sandwich Plates Structure

This thesis takes the second stage aeration tank of Harbin wenchang sewage treatment plant project as the engineering example, studies the application of the prestress technology on super-long rectangular pool. Through the internal force analysis and structural design of super-long rectangular tank'wall, this thesis studies the construction technology of prestressed reinforcement, and researches on the applicability and feasibility of prestress technology on water tank structural design. Main research contents are as follows:(1) Through the study of the application of unbonded prestress technology on the super-long structure, the key problems in the design of super-long water tank are discussed. For super-long tank structure, on the premise of satisfying the ultimate limit state, the key point is satisfying the serviceability limit state, which just is the requirement of impermeability. The design key point of water tank structure is on the control of the crack width, and prestress technology just can make up the defect of common reinforced concrete, and then the requirement of crack control is satisfied.(2) The construction technology of unbonded prestressed reinforcement is studied. On the rectangular tank the unbonded prestressed reinforcement is divided into two kinds of the horizontal and vertical direction. For horizontal prestressed reinforcement the tension at two ends is used, and tension in batches is adopted. For vertical prestressed reinforcement the tension on one end is used and the tension is adopted on the top of tank'wall. The tension at two ends simultaneously in horizontal direction can guarantee that the forcing of tank'wall is Symmetrical and uniform.(3) The numerical simulation of forcing of the super-long tank structure is carried on. Two load cases are defined. One is the situation of full water in the tank and no temperature stress; the other is the situation of full water in the tank considering temperature stress. Two kinds of model are built and compared, through which, the active role of walkway plate on the top of wall in resisting the water pressure is studied. Because the top end of the tank'wall is simple support, the larger temperature stress will generate in the wall, and the setup of walkway plate must be combined with the local climatic conditions.(4) The model of that the top of long wall is free and the top of short wall is simple support is studied emphatically. In this model, the moment distribution in the wall presents fluctuation phenomenon, and the maximum moment doesn't generate in the wall temperature stress acts, but generates in the adjacent wall, which provides the reference for engineering design.