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

With the development of the economic society, more and more old buildings can not meet the requirements of current production and livings, so reinforcing the old buildings, one important part of which is transformation of large space at the bottom of the masonry structures, is paid increasing attention to. And underpinning technology plays an important role in the reinforcement. The choose to underpinning technology directly related to the overall appearance and normal use of the reinforced buildings. In addition, underpinning technology also plays an important role in many other fields about construction work.Given the important of underpinning technology, there is great practical significance in its study. After summarizing previous research on the underpinning technology, we propose a new underpinning technology., using steel-masonry composite beam as underpinning beam. The technology is wrapping angle iron outside of the top of the original brick walls and connecting angle to each other with steel batten plates and bolts. Simultaneously reinforcing upper wall makes the structure work together in order to improve the performance of the overall force. Compared with the traditional underpinning technology, the new underpinning technology with easy construction, low cost, and many own advantages lays the foundation for its application.By the four sets of static test specimens, we get the load-strain curves, load-deflection curves, cracking load, ultimate load and other performances of the specimens. This paper also studies the mechanical behavior and failure mechanism of underpinning structure under the vertical loads, and simultaneously explore the role of different factors on the structural bearing capacity and engineering properties. The results show that, underpinning structure, forming the wall beam structure, is conducive to full interaction between the various parts; simultaneously, the upper reinforced wall, which damages first in the loading process, is still weak compared with lower underpinning beam. Final destruction of Models is local compression failure of the wall-beam structure, and it is premature destruction of the upper wall that makes the bottom underpinning beam fail to give full play to its loading capacity. Completion of test fills in the gaps of the technology in the field of experimental and theoretical studies effectively, and provides guidance on promotion and application of engineering practice for this underpinning technology.