| With the rapid development of cross-sea bridge and offshore wind power projects,the application of pile foundation has moved from land to deep water field,which brings many challenges to engineers and technicians,among which the scour effect is a more prominent one.Scour is a natural phenomenon in which water flow and waves erode the soil around underwater structures.For the pile foundation bearing both vertical and horizontal loads,erosion may lead to the degradation of its bearing capacity,and even induce the collapse of the bridge superstructure,which will cause huge casualties and economic losses.Therefore,it is of great practical significance to study the influence of scour effect and vertical load on the horizontal bearing capacity of pile foundation.The main work is as follows:(1)Considering the influence of scour pit size,a series of horizontal static loading model tests of single pile were carried out in sand soil.The influence law of scour pit size on the internal force,deformation and p-y curve of pile was discussed.Meanwhile,PIV technique was introduced to analyze the development law of displacement field and positive strain field of soil around pile under scour condition.(2)A series of horizontal load model tests of single pile were carried out in sandy soil considering the vertical load and scour,and the influence of these two factors on the internal force and deformation characteristics of the pile was discussed.Meanwhile,the influence of these two factors on the deformation characteristics of the soil around the pile was analyzed based on PIV technique.(3)In theory,the vertical load of pile top and the horizontal displacement of pile will cause the change of vertical shear stress on pile side,which is expressed by the hyperbolic shear stress-displacement relationship.The additional vertical effective stress caused by the load at any depth of the pile side was calculated to consider the local scour effect.The two factors are coupled to the modified strain wedge model for horizontal load analysis of pile foundation,and an improved modified strain wedge method is proposed.The MATLAB program is edited based on the finite difference method,and the correctness of the method is verified by experiments.Figure[77] table[4] reference[73]... |
