Research On Instability Mechanism And Reinforcement Technology Of Rammed Earthen Architecture Site In Arid Area Of Northwest China

The earthen architecture site is the historical relics of the ancient buildings that are left by ancient human activities.The land remains in the northwest arid area of China are more concentrated,especially the rammed earthen architecture site.In the long-term natural environment and external force,rammed soil due to pull and crack,shear and crack,crack extension gradually through,commonly showing as collapse,instability and other forms of damage.The paper counts and analyzes the structural diseases of a large number of the ancient city Gaochang,and points out that the rammed earth ruins of arid area can be divided into five kinds of failure modes as tangled collapse,cracked collapse,mixed collapse,wall overturned,the collapse of the coupons,its impact factors,instability and disaster mechanism were studied.In order to control the tensile and shear stress,the method of unsteady reinforcement is discussed.Through the field investigation and the mechanism of instability,the paper puts forward the common destabilizing form,and discusses its mechanism and protection method by numerical simulation.The main contents of the paper are as follows:(1)Under the action of self-weight and external force,the destruction of earthen architecture site is controlled by tensile stress and shear stress.Its instability form is Expressed as five kinds,erosion collapse,cracking collapse,mixed collapse,wall overturning and coupon collapse.(2)Taking the large site of the ancient city Gaochang as a sample,the position and size of each site of instability are analyzed in detail,and the range of size change is obtained.(3)For different instability phenomenon,The effects of factors such as depth,crack length,crack location,wall thickness and wall height on the instability mechanism were studied by numerical simulation method.(4)Combined with the influence of each size on the instability mechanism,the occurrence conditions and reference dimensions of the mechanism such as the lateral cracking,the top cracking,the crack at the bottom of the crack and the cutting of the floating area are given.(5)Under the different failure mechanism,the soil structure is strengthened by controlling the maximum tensile stress,improving the shear strength and improving the boundary condition,and the reinforcement effect is compared with the corresponding damage mechanism.