关键词: 倾斜长短桩, 模型试验, 砂土地层, 基坑开挖, 围护结构位移, 桩身弯矩

Abstract: Inclined piles can improve the horizontal bearing capacity of row piles. The longshortpiles can reduce the pile length of part of the supporting pile according to the pile moment distribution and to completely use the supporting pile bearing capacity. The combination of these two forms the inclined longshortpiles. To study the deformation force characteristics of inclined longshort combined piles as foundation pit retaining structures, the influence of inclined long pile inclination angle and long and short piles ratio are analyzed using conventional indoor sand model test. The test results show the following: (1) Compared with long piles with equivalent lengths, the inclined longshortpiles can effectively control the deformation and pile moment when the total pile length is reduced. (2) When the inclined pile inclination angle ranges from 0° to 20°, the support effect increases with an increase in inclination angle. (3) The pile moment of the inclined longshortpiles decreases with an increase in inclination angle, and the decrease of moment below the excavation surface is much greater. (4) The bending moment of longshortpiles above the excavation surface is similar, and that below the excavation surface of long piles is considerably larger than that of short piles. (5) The higher the proportion of short piles, the weaker is the support effect and the larger is the bending moment of piles.

Key words: inclined longshortpiles; model test, sandy soil strata, foundation pit excavation, retaining structure displacement, pile bending moment