Experimental Study on Mechanical Properties of Laminated Bamboo Board Rubber Isolation Bearing for Rural Buildings

Abstract

A new type of isolation bearing with advantages of low carbon, low cost and light weight is designed for rural buildings by using reinforced and recombined bamboo board instead of steel plates. First, the compression shear static load test of the reinforced composite bamboo board is carried out. The results show that: When the pure pressure is 20 MPa, the through cracks begin to appear along the grain direction of the bamboo board; When the pressure bearing capacity is 5 MPa and the shear bearing capacity is 3 MPa, there are a few cracks in the transverse direction, but they still have integrity. Then, taking a double story rural building in Wenchuan County, Sichuan Province as an example, a new type of bearing is used to design the base isolation scheme, and the quasi-static test was carried out. The results show that: (1) During the small earthquake, the bamboo board is not cracked, and the support remains intact. The shear stiffness in the longitudinal direction is about 30% higher than that in the transverse direction, and the equivalent damping ratio in the longitudinal and transverse directions is about 5%; (2) During the medium earthquake, a few cracks appear in the bamboo board, but the support is still intact. The stiffness along the grain direction is reduced by about 20%, but the damping ratio remains unchanged, and the mechanical properties along the grain direction are not affected; (3) During a large earthquake, there are many cracks in the bamboo board, but the bearing can still effectively bear the load. The stiffness in the longitudinal direction is further reduced by about 13%, and the transverse direction is basically unchanged. The damping ratio in the longitudinal and transverse directions is increased to 8–10% respectively. Therefore, the new isolation bearing is feasible.