Pseudo-static Test Of Round Tulou With Damage In Service

Fujian Tulou is located in the southeast coastal areas of earthquake,wind and rain,under the influence of the environment and human factors,it has suffered heavy damage,and even part of the extinction.This paper mainly studies the pseudo-static test of circular walls with different damages in circular earth buildings,and provides some references for the seismic reinforcement of circular earth building walls.Based on the field investigation of the earth building,this paper summarizes the damage characteristics of the outer wall of the circular earth building,partial damage characteristic wall is selected for the pseudo static test,then through the finite element simulation,the effect of different damage on the seismic performance of the wall of the circular earth building is compared and analyzed.The main research work of the thesis is summarized as follows:(1)Conduct field surveys on circular earth buildings to statistically measure and analyze the damage characteristics of circular earth building walls.Four kinds of representative damage cracks were selected: horizontal construction joints,vertical dry shrinkage joints,window seams and combined joints.(2)Based on the integrity of the soil building,the C5 concrete was used instead of rammed earth to design a scale model of five circular soil buildings with different damage cracks,and a pseudo-static test was conducted.The vertical loads and low-cycle repeated horizontal loads were applied to the specimens to study the characteristics of the hysteresis curves and skeleton curves of the walls under the earthquake load,as well as the horizontal bearing capacity,deformation capacity,and stiffness degradation performance of the walls.Through the experimental comparison,the propagation of different damage cracks and the ultimate failure mode of the wall are observed;The effects of different damage fractures on the mechanical behavior of the wall are analyzed;point out major damage cracks that affect the seismic performance of the wall.The test results show that when the annular wall of the earth building is finally destroyed,horizontal cracks penetrate through the push-pull surface,and vertical cracks and window angle oblique cracks extend to the foot of the wall.Among the different prefabricated cracks,horizontal construction joints have the greatest impact on the seismic performance of circular soil building walls,followed by vertical cracks.(3)Two test specimens were selected to perform finite element simulation,using C5 concrete and rammed earth to simulate.Through C5 concrete simulation and comparative test results,the failure modes and seismic performance of circular soil buildings under different damage cracks are consistent with those of the simulation,and the validity of the simulation is verified.Through the simulation of rammed earth,the failure mode of the wall was observed,and the necessity of C5 concrete instead of rammed earth test was obtained.Analysis of comparative test results to further verify that the concrete model test results are applicable to rammed earth wall of Tulou.