Experimental Study On Behavior Of Steel-Concrete Composite Structure In Masonry Structure Underpinning

With the development of the social economy and the continuous improvement of people’s living standards, people work, live and living needs are undergoing tremendous changes, people requires the use of the function of the building has changed a lot, and some of the old buildings often due to long years of construction, housing and into the deep bay are relatively small, it is difficult to meet the people’s requirements for the use of building space, so the actual project often requires transformation of existing buildings. Solve this problem, there are two common methods:demolition and reconstruction and underpinning transformation. Demolition and reconstruction is necessary to face the problem of time, technology and finance and other aspects, will produce large amounts of construction waste on the environment caused by pollution. Compared with the demolition and reconstruction, underpinning the transformation of a small pollution, short duration, saving resources and investment, etc, it became the most effective means to solve this problem.Steel-concrete composite beam structure as an underpinning, this underpinning technology can be the first construction the composite beam, and then remove the lower part of the wall, without the support of the upper structure of the construction, the construction is simple, safe and reliable construction short duration, and the composite beam bearing capacity. Compared with the traditional underpinning technology, it has obvious advantage.Through the three experiments on the steel-concrete composite structure, we got the failure characteristics of the specimen, the load-strain curve, the load-deflection curves and ultimate load of specimens and other properties. The test results showed that:the specimen during the loading process, the upper concrete is in compression, the lower channel is in tension, concrete and channel can work well together, under load, the upper part of the specimen are ultimately crushed concrete, component damage, damage in the form of composite beam flexural failure; brickwork in the channel beams are crushed, indicating the holder of the coming bear the pressure of the channel to prevent premature buckling failure.The steel-concrete composite beam can be calculated as the composite structure.