静载荷试验中压重平台引起的地表位移分析

Analysis of Ground Displacement Caused by Weights Platform in Static Loading Test

在基桩静载荷试验中,由于加载压重平台反力装置引起地表位移,使测得的桩顶沉降值不准确,进而影响基桩极限荷载的正确取值,因此,有必要对加载过程中压重平台引起的地表位移进行分析。为此,将精密水准仪量测系统引入到静载荷试验中。通过对现场试验资料分析,得出了地表位移的大小以及地表位移的规律。最后,应用有限元方法并结合现场试验资料分析了地表位移的影响因素:地表位移大小与土体的变形模量成反比例关系,与加载压力成正比例关系。

In pile foundation static load test,ground displacement may be caused by the weights platform of counterforce device during loading,leading to incorrect subsidence value of pile top obtained,moreover,the value of ultimate load of pile may not be selected correctly.Therefore,it was necessary to analyze the ground displacement caused by the weights platform during loading,then the precise level measuring system was introduced into the static load test.Through the analysis of the test data,the quantity and law of ground displacement was found out.At last,finite element method was used,with the field test data,the factors influencing the ground displacement were studied that the quantity of ground displacement has inversely proportional relationship with the deformation modulus of soil mass,and directly proportional relationship with the loading pressure.