The Study Of Bearing Performance And Laboratory Model Test On The Inclined Loaded Piles Located Near Slopes

Since the resource of usable lands gets to reduce considerably in modern urban civilization and communication construction, the high-rise buildings, bridges and transmission tower etc. have to be directly constructed on the top of the slopes. The piles are used to both reinforce the slope near the construction and carry the superstructure-induced loading and the additional lateral loading, such as violent winds and earthquakes. The bearing performance of the piles and the mechanism of slope-soil-pile interaction become much more complex than general stabilizing piles against landslide or simplex inclined-loading piles. For the inclined loading piles located on the top of the slopes, the slope-pile interaction mechanism, load transfer laws and bearing performance have yet not been clarified until now, the conventional calculation method and analysis theory for piles are already not fit for the present application. Combined with the Natural Science Fund of Liaoning Province, the computation method for pile performance and the laboratory model test for pile bearing mechanism are systematically investigated. It will be theoretically important and practically significance to examine the mechanism of piles in both stabilizing the slope and carrying the inclined loads and to discover the interaction effect of piles-soil-slope. The details on the paper are listed as follows:(1) Based on comprehensive analysis and evaluation of the research work on pile under assembled loads at home and abroad, the pile can be divided into three characteristic segment from the mechanism behavior: the free segment, the loaded segment and the anchored segment. Then, the factors such as P-Δeffect, landslide-thrust of a slope, subgrade coefficient, friction resistance of pile shaft and dead load of pile are considered and the differential equations of the characteristic segments of the pile are obtained. Power progression solution for single pile is derived using "m" method. Horizontal displacement of pile is assumed to have a longitudinally ten times power function, and then a corresponding computer program using MATLAB is developed to solve the displacement, bending moment, shear force and lateral soil pressure acting on the inclined loaded piles. Moreover, the computation method is again applied to the inclined loaded piles in layered soils slopes. A case is used to check the reasonableniss of the solution.(2) To understand fully the bearing performance for the inclined loaded piles on the top of the slopes, a series of laboratory model tests are carried out. Silty slope is chosen, and the large model tank and inclined loading devices are designed. In the model test, rigid concrete short piles are used, 11 contrasting model tests including the different angle of slopes, inclination of loading, horizontal distances from the pile to the crest of the slope, the embedment length of the piles are performed to measure the displacement, bending moment of pile shaft, latera earth pressure acting on the piles. Based on the above detailed investigation, the distribution laws on the internal force and lateral earth pressure are substantially found.(3) According to the measured results on the 11 model tests, the curves on the horizontal displacements versus inclined loads, lateral earth pressure versus horizontal displacements are drawn, and the distribution on the bending moments, lateral earth pressure acting on the piles, horizontal displacements along the pile length under different inclined loads are also made. Through the comparative analysis, the bearing deformation mechanism, load transfer laws and working performance for the inclined loaded piles located on the top of the slopes are obtained, and also the deformation of the slopes. Then, the difference of performance for the inclined loaded piles located on the horizontal ground and on the top of the slopes is also found. Moreover, the potential distribution types on the P-Y curves and the simplified unified P-Y curves are also given according to the comprehensive analysis on the latera earth pressure and horizontal displacements of pile shaft. The above research results will have a significant effect on the revision of the related codes and the improvement of the engineering design...