Experimental Study On The Stress-strain Full Curve Of Tulou Rammed Soil Under Monotonic Loading

As a precious historical and cultural heritage,Fujian Tulou has a long history,with distinctive architectural characteristics and cultural style.However,the complete earth buildings are on the decrease,and this historical treasure is being destroyed by time.China has implemented protective measures for earth buildings since 1996.Obviously,protecting this historical and cultural heritage is very important.The performance of rammed soil material has a great influence on the strength and deformation of the structure,but the research on the mechanical properties of Fujian earth building rammed soil material is almost blank,so the research on the mechanical properties of rammed soil material is particularly important.Based on the stress-strain curve of rammed earth material,this dissertation conducts a comprehensive study of the mechanical properties of rammed earth material.The main work done is as follows:(1)Sampling directly on the wall of the abandoned earth building in the Gaobei Tulou Group in Yongding,using a rock cutter to make a 100 mm ×100 mm ×200 mm prism test block,and performing uniaxial compression tests under strain loading such as displacement control.The measured stress-strain curve is carried out to obtain a series of mechanical characteristic coefficients that reflect the strength and deformation of the rammed soil material,such as prism strength,elastic modulus,Poisson’s ratio,and so on.When making the test block,observe the rammed surface and divide the test block into two types of test blocks that are parallel and perpendicular to the rammed surface.Based on the test results,compare the mechanical characteristics of the rammed soil material in two directions,determined that the rammed earth material is an anisotropic material.The test results provided reliable material basis for the structural analysis and calculation of Fujian Tulou.(2)Following the undisturbed soil test,the crushed rammed earth material was used to refer to the ramming process of the actual earth building,and two different prisms of the same specification were remade.Similarly,the measured stress-strain curve is obtained through uniaxial compression test,and physical quantities such as prism strength,elastic modulus and Poisson’s ratio are further obtained.Compared with the test results of undisturbed soil,and consider that the remolded soil is the new earth rammed earth material,analyze the difference between the mechanical properties of the new earth rammed earth material and the rammed earth material after hundreds of years.(3)With reference to the research method of uniaxial constitutive relationship of concrete,combined with experimental measured data,uniaxial constitutive models of four test blocks were obtained by nonlinear fitting.