Study On Stress Path Test For Foundation Excavation And Deformation Analysis By Finite Element Method

The retaining and protection of foundation excavation engineering isa kind of special and temporary engineering, lts defomation andstabilization come from analytic theories of slope, and develope as thetheories develop. From all the deformation and stability influencingfactors of foundation pit, the distribute of the esrth pressure is the mostimportant. The settle of esrthpressure is depend on the selection of thesoil index. Through engineering experience accumulate and summarize bymany years, people have put forward various esrth pressure calculationmethods. The ture earth pressure by monitoring is different fromcalculational earth perssure by thses methods, and it also different fromclassic earth pressure of Coulomb and Rankine. With the development ofthe calculator, people put forward finite element method to analysis thedefomation and stabilization of the foundation pit. As soil isviscidity-elastic-plastic material, and its deformation and mechanicsindex are also influencing by stress path, various analysis havedifference result.The paper with the deformation and stabilization of foundation pitas mian line, and found the unloading constructive model by triaxialcompression, K₀ consolidation and lateral unloading test. It also analysethe defomation and stabilization of the foundation pit through settingup finite element analyse model by sofeware of ANSYS, and elaboratefoundation pit defomation influence that cause by ture stress path. Allof this are using to guide foundation pit design and construction.Hereby, this paper do some research about foundation excavation asfollows.1. By using TSZ-2 serieses full-automatic triaxial apparatus, wesimulate the ture stress path of the soil that behind supporting structurein foundation excavation, and get the mechanics index of soil underunloading condition. The index is using to contrast with the index thatgetting by triaxial compression test. All work is to analyse the influenceof soil shear strength by different stress path.2. According to triaxial unloading test curve and imitating the founding method of Duncan-Chang model, we have deduced the undoadingconstruct model.3. With triaxial unloading test result, we found the finite elementanalyse model by sofeware of ANSYS, and study the deformation of supportingstructure that under different activities when foundation excavation. Theresult of model analysis is contrasted with the spot monitor data.