Shaking Table Test And Numerical Simulation Analysis On The Strengthening Performance Of Free-standing Stone Cave Dwelling

Cave dwelling is a typical traditional house with great regional characteristics in the Loess Plateau in northwestern China.It is also the oldest form of residence,which is widely distributed in Shanxi,Shaanxi,Gansu,Henan and Ningxia provinces.So far,a considerable number of people still live in caves in the vast rural areas of the Loess Plateau.Due to natural disasters such as frequent earthquakes in recent years,a large number of caves have been damaged to varying degrees,which severely endangered the lives and property safety of local residents.In addition,the current national implementation of targeted poverty alleviation and earthquake resistance reconstruction of rural houses in high-intensity areas.The major strategy urgently needs to carry out seismic reinforcement research on the stone cave dwelling with wide distribution,large living volume and poor seismic resistance.At present,most of the research on cave dwellings is still limited to the physical and mechanical properties of materials,static and dynamic finite element analysis,and the theoretical and experimental research on seismic reinforcement is relatively few,especially for the seismic reinforcement of free-standing caves dwellings.The simulated earthquake test research is still blank.To this end,the research group carried out the shaking table test of the free-standing stone cave dwelling in the early stage to study its seismic performance.Based on this,this article will further explore and study the seismic strengthening performance of the free-standing stone cave dwelling.Reinforcement technology such as reinforced mortar belt was used to reinforce the seismic-damaged model of a free-standing stone cave dwelling with a scale ratio of 1:4.El Centro Array #9 wave,LA-Hollywood Stor FF wave and artificial wave input tests,to observe its destruction process and destruction form,to study its dynamic characteristics and dynamic response laws,and to analyze its torsional effect and energy consumption under earthquake action ability.The experimental research results show that: with the increase of the peak acceleration of the input seismic wave,the natural frequency and stiffness of the model structure decrease,the damping ratio and the energy consumption of the structure gradually increase,and the acceleration amplification factor generally shows a downward trend;the difference in lateral stiffness of the structure and the spectral characteristics between seismic waves has a great influence on the dynamic response of the model.For the acceleration response,the LA-Hollywood Stor FF wave is the largest in the X direction(wide direction)but in the Y direction(depth direction),the response caused by El Centro Array #9 wave is the largest.The kiln face side arch coupon is greater than the back wall side arch coupon,and the middle hole arch coupon is greater than the side hole arch coupon.For the displacement response,the relative displacement value of the middle arch foot is always greater than the side arch foot,or even greater than the side arch peak;After an earthquake with an acceleration of 1.0 g(rarely exceeding 8 degrees),the natural frequency of the model in the X and Y directions respectively decreased by21.8% and 25.5%,and the X direction of the top,dome and arch foot of the structure is known to the maximum side the shift angles reached 1/48,1/224 and 1/145,and the torsion angle reached 1/208.The local damage of the structure was serious,but the overall collapse trend did not appear,indicating that the method proposed in this article the effect is significant,reinforced stone cave dwelling structure has a good shock resistance.On the basis of the experiment,the finite element software ABAQUS was used to establish an earthquake-reinforced free-standing stone cave dwelling model,which was subjected to dynamic response and earthquake damage analysis,and the numerical simulation calculation results were compared with the test results.The results are in good agreement,which verifies the feasibility of the program for the seismic analysis of the free-standing stone cave dwelling seismic strengthening model.