Erperimental Study On Load-bearing Characteristics Of Sand Foundation Affected By Ground Water Level Changes

Water source heat pump technology is a kind of air-condition technology, which uses the energy store in water as cold and heat source to conversion. Water source heat pump can be classified into ground source heat pump and water-loop heat pump. Drawing water and recharge are two important processes of water source heat pump system, in process of system operation, underground water level declines and ascends along with pumping and injection, in this condition, it is necessary to analyze and assess geotechnical engineering problems arising from the change of ground water level.The purpose of this paper, by means of indoor model experiment, theoretical analysis and numerical simulation method, to test engineering property variation behavior of sandy soil foundation caused by the change of underground water level, in view of the above goal, this paper makes following jobs:1.This paper Carried out indoor model experiment, use data of collecting soil pressure sensor and water pressure sensor,make static load test on the conditions of natural water content and saturated water content, analysis the character of foundation affected by change of water level, draw some conclusions, such as friction angle decrease with the increase of water content,The load eigenvalue of sand foundation in saturated case is less than that in natural water content; foundation will have small settlement with decline of the water level.2.Looking for theoretical explanation base on conclusions of indoor test, analyze the causes of various phenomena, provide the theoretical support.3.Select the suitable parameter and constitutive model, simulate indoor test by the Finite Difference Method software,FLAC3D, compare results of simulation and experiment, analyze its law, obtain some conclusions, such as simulate dense sand by FLAC3D , in the condition of natural water content, its can identical with test data; in the condition of saturated water content, the results of numerical analysis are identical with indoor test data between 0 to 900kpa, when load reach 900kPa and continue to upload, appear large deviation, now it can compensate for this error by fitting formulae;then in process of artificial recharge and pumping pressure dense, the influence of pore water pressure affected by mechanical process is very small, it's can be ignored.The result of this paper will provide helpful guidance and advice for further development of the promotion work of water source heat pump.