【摘要】 为满足既有砌体结构对底部大空间的需求，在将砌体结构改造为底框结构时，双梁托换技术应用广泛。文章结合工程实例对托换梁结构在底层砖混墙拆除后的力学性能进行了现场试验研究，现场测试了托换梁及夹心墙变形、托换梁钢筋和混凝土的应变数据。结果表明：一层砖混墙体拆除后在自重作用下托换梁跨中挠度较小，托换梁与夹心墙粘结性能良好；托换梁跨中正弯矩截面和支座负弯矩截面受拉钢筋应变和应力非常小；采用双托梁加肩梁的技术能够有效将二层以上的荷载传递至托换梁，且具有较高的安全性和较大的安全储备。更多还原

【Abstract】 In the masonry structure, due to the demand of large space at the ground floor, the masonry structure is transformed into the bottom frame structure, and the double beam underpinning technology is widely used. In this paper, the design of underpinning beam structure is experimented, and the deformation of underpinning beam, sandwich wall, reinforcement strain and concrete strain data of underpinning beam are tested in the field. The results show that the deflection in the middle span of the beam is small after the first layer of brick wall is removed, and the bond between the beam and the sandwich wall is good. The strain and stress of the tensile reinforcement of the positive bending moment section and the negative bending moment section are very small. The results show that the technology of double beam underpinning with shoulder beam can effectively transfer the load to the underpinning beam and has high safety and large safety reserve in engineering application.更多还原