| At present, cast-in-situ concrete electrical manhole is large number of applications in the domestic. Long construction period, environmental influence, takes up a lot of space and resource consumption, These factors make it more difficult to meet the needs of urban construction development. Prefabricated electrical manhole can use the land resources effective, alleviate the pressure of the urban space, overcome the disadvantages of the cast-in-place concrete work well. It have the advantages of rapid construction, little influence on environment and product quality is guaranteed. It can meet the requirements of structure and the permeability in various aspects. Prefabricated electrical manhole is the development tendency t of the modernization construction. Side panel and roof is the main components of the electrical manhole. To study the feasibility of the prefabricated electrical manhole, that experimental research and theoretical analysis was carried out on the plate is necessary. Modified on the basis of existing achievements, the embedded filler is decorated in the concrete slabs to reduce the weight of plate. That the mechanical properties experimental and destruction form has been studied for eccentric compression plate in combination with the actual stress state of the side panel and roof in underground.Considering the influence factors, such as the same conditions of the hollow ratio and eccentricity, reinforcement ratio and reinforcement way. Two piece of normal Reinforced concrete hollow slab and two pieces of ceramsite concrete hollow slab have been studied based on the eccentric compression test. Studying the mechanical performance, failure mechanism and analyzing influence of core module arrangement for bearing capacity. Using ANSYS software of finite element analyze reinforced concrete hollow slab and compared with the test results. The concrete solid slab is established under the same conditions. The impact effect of hollow ratio and mandrel continuous arrangement on the bearing capacity of the hollow plate is considered.The test results show that four pieces of hollow slab are large eccentric loading damage form, all of them have enough bearing capacity. Stress of rebar and crack forms are basically same, the changes of flexural deformation, the failure mode belongs to the ductile fracture, the bearing capacity and crack resistance of hollow slab with mandrel vertical arrangement is superior to the hollow slab with mandrel horizontal layou under the same condition of other parameters.Specification method is applied to calculate the bearing capacity of normal section of the reinforced concrete hollow slab. Test value is greater than the theoretical value. That hollow slab structure design can meet the specification requirements, it has adequate safety space.The results of the ANSYS analysis and the experimental are basically same. The hollow slabs are large eccentric loading damage, and the characteristic is ductile fracture. The finite element analysis results show that the bearing capacity, deflection, steel bar stress changes, fracture distribution and failure mode of the concrete solid slab and the Mandrel longitudinal decorate hollow slab is basically the same. Bearing capacity of hollow slab decrease when rate of the hollow increase. The reduction of Capacity is small when the hollow rate is not big. Cross rib of hollow slab with mandrel discontinuous layout is beneficial to bearing capacity. |
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