The Static Load Test Of Steel Strand Anchor Pile And Numerical Analysis

This thesis which is focused on the optimizing of tensile member of anchor pile which is made of steel strand is relying on the third phase of the project of Greenland Center in Urumqi.The data that were collected from static load test of single anchor pile and numerical simulation in field experiment are used to draw Q-s curve,s-lgt curve and Pile axial force curve,calculate transmission of axial force and pile shaft resistance and analyze single pile load-sedimentation curve,axial force curve and the character of carrying capacity.The main results are as follow:(1)The method,static load test of anchor pile,is optimized,and the tension component of anchor pile is designed with steel strand.The practice shows that anchorage device can decrease the duration of installation,and the tensile yield strength of strands is much stronger than the tensile yield strength of steel,which results in that the number of using material are less than steel.Thus,it reducing the engineering cost heavily.Additionally,the reaction force component,using steel strand as this part,is easy to make every steel wire forced evenly.(2)Q-s curve which is a slow-change type is got by the test,static load test of single anchor pile,in field experiment.With the increasing of load,the sedimentation of pile block is increasing gradually.Until to the maximum load,test piles,SZ03 and SZ04,are not destroyed,and the final sedimentations of both test piles are 18.60 mm and 21.54 mm,respectively.It can be seen by the pile body axial force curve and end resistance curve that axial force is decreased from the pile top to bottom.Under the force of load,the resistance of the first two phases is almost 0,and the curve of the end resistance shows an inflection point at the seventh level of load.After that,the end resistance is increased dramatically.The results show that with the increase of pile top load,the axial force of the pile is decreased slowly from the pile top to the pile end,and the friction resistance of the pile side soil layer is increased gradually from top to bottom.As for the pile end resistance,it is almost zero at the beginning,but it is increased slowly.Side friction resistance and end resistance are not synchronized to play.(3)The Q-s curve of SZ03 test pile is simulated by ABAQUS finite element,and the curve is slow-change type.With the increasing load on the top of the pile,the settlement of pile block is increased linearly.The final settlement is 21.18 mm which is close to the test data.So,this method is workable.The pile-soil displacement of clouds,stress of clouds and stress and strain of pile of clouds can be gained base on this model.Clouds show that there is a large relative displacement between the upper part of the pile and the soil layer,and there is a small relative displacement between the lower part of the pile and the soil layer.Pile compression is decreased gradually from its top to its bottom,and the amount of compression at the bottom almost close to 0.The stress and strain of the pile are decreased gradually from its top to its bottom,and the stress which comes from soil layer is small.