Study On Lateral Load Field Test And Force Character Of Single Pile And Group Pile In Deep Soft Soil

Pile foundation is widely used in modern construction projects,especially in the The pile foundation is widely used in the construction of the foundation bearing capacity of poor area.In soft soil area,the late construction has an impact on the pile formation been built,which become passive pile.In the process of construction in deep soft soil area of coastal,disturbance of soil around pile causes the large deformation of the pile,and even leads to devastating damage.Therefore,carrying out the study of field test of passive pile and its force characteristics is of great significance in engineering,can reliably guide engineering construction,and put forward reasonable suggestions.In this paper,combined with the Fuzhou port railway line engineering construction,through on-site lateral pile load test of bored single pile and pile group of force character,rock socketed single pile soil mutual interaction theory analysis and numerical simulation to study passive pile mechanical properties and deformation rules,the main contents are as follows:(1)Carrying out field test,thought vertical and horizontal static load test of single pile analysis the load on pile top in the relationship between the transmission mode and the load of the pile body and deformation;From single pile and two pile cap structure side grading loading test,we calculated the relationship of loading distance and the internal force of pile,the relationship of loading distance and displacement of pile,and the relationship of loading height and the internal force of pile and relationship of loading height and displacement of the pile;Research shows that the smaller distance and the greater height,internal force and displacement of the pile is bigger.Comparing with single pile and two pile cap structure of pile under lateral loading force with the availability of two horizontal displacement of pile cap structure is significantly less than the single pile structure and get barrier effect of pile to pile front,and make relevant discussion.(2)From vertical and horizontal aspects,relationships of pile-soil and pile-rock interaction of embedded rock pile and analysis method are introduced,detailed introduces the embedded rock pile's relationship interaction of pile-rock.Quoting model of "three stages"and correcting the formula derivation of pile shaft force and lateral friction resistance in order to obtain a more precise conclusion.And discussing of rock socketed depth from the horizontal load.(3)Using finite difference software FLAC3D numerical simulation of single pile and pile cap site test conditions,analysis the displacement field of soil around the pile under lateral load and analysis the relation of pile axial force,bending moment and displacement and load respectively,contrast test and numerical simulation results.Analysing the similarities and differences about them..(4)According to the actual situation of the Ke Men port bridge,establishing of pile group(four pile)model numerical analysis,obtaining the index of the pile body variation performance under the classification of lateral load;combining with stress traits of single pile and two pile in the corresponding conditions,comparing the similarities and differences between the two,verifying the front pile of back row pile "sheltering effect.It is found that the cap with four piles bearing performance is better than that of single pile and two pile,to provide guidance in the post construction.(5)Under lateral load,contrasting high cap and the lower cap by the relationship between bending moment,axial force and pile body deformation discussing the pile of restriction effect of the high and low pile cap;Analysising the force characters of the front row of the pile and the rear pile under lateral load b,and putting forward some suggestions for the selection of the pile cap.