Elastic-plastic Analysis On Stress And Deformation Of Building Rectification With Under Excavation Method

Tilting of building is a thorny engineering problem.Inclined buildings not only affect normal use functions,even cause collapse in serious cases.The development of building rectification technology provides solutions and methods for this problem.The building rectification of underexcavation technology is widely used due to its economics,safety and convenient construction.Therefore,this article focuses on the study of the underexcavation correction method.The hole spacing is an important factor that affects the safety and construction period of the building rectification project,and the determination of the hole spacing is closely related to the development of the plastic zone of the soil around the holes.In order to determine the distance between the excavation holes in the building rectification project quickly and accurately,the analytical method and finite element simulation are adopted to study the development of the plastic zone of the soil around the holes.The similarities and differences of the radius of the plastic zone around the hole with a single hole and the porous case are explored.Firstly,the analytical and numerical solutions of the plastic radius of the hole with respect to single hole are obtained using plastic mechanics and finite element methods respectively.It is found that the Rubine’s analytical solution is more closer to the numerical simulation solution.Secondly,the plastic zone is studied with respect to multiple holes.The hole spacing is defined as the critical hole spacing S when the plastic zone around the hole is tangential,and half of this hole spacing S is taken as the radius of the plastic zone around the hole.The radius of the porous plastic zone is about 1.3 times of the single-hole plastic zone with comparisons.Further,the factors affecting the development of the plastic zone are considered.The two main factors of soil parameters and upper load are mainly analyzed.Two typical soil types,silty and clay,are selected to consider the influence of the randomness of the soil,and the upper load is considered with respect to the bearing capacity.The relationship between the ratio p(standard load value)of the upper load to the bearing capacity of the foundation and the ratio n of the plastic zone radius to the hole diameter(p-n curve)is obtained,and the value of the hole space can be estimated through this curve.Finally,the research results are applied to three building rectification of horizontal underexcavation engineering projects.The suggested values of the hole spacing are quite close to the actual used values of the projects,this can provide a reference for the determination of the hole space in building rectification project.