【作者】 齐艳萍；

【导师】 何光春；

【作者基本信息】 重庆交通大学 ， 港口、海岸及近海工程， 2011， 硕士

【摘要】 本文系统阐述了嵌岩群桩的承载机理和群桩的沉降计算方法,结合纳溪沟码头工程,借助ABAQUS三维有限元数值模拟方法建立了嵌岩群桩的理想计算模型,对影响嵌岩群桩承载性能的因素:桩长、桩径、基岩强度、嵌岩深度等进行了深入的分析研究,得出以下结论:(1)在有限元数值模拟结果中,中心桩与角桩的桩顶沉降量以及桩顶水平位移差值较小,获知嵌岩群桩的群桩效应并不明显。(2)群桩在竖向荷载作用下,刚性承台与桩共同承担荷载,承台周边应力大于承台中部应力;荷载传到下部各桩上时,角桩桩顶荷载均比中心桩桩顶荷载大。(3)在同一荷载条件下,中心桩和角桩的桩径越大,桩顶沉降越小,沉降曲线趋于一定值;当桩径达到1.8m以后,桩径对桩顶沉降的影响减小,且中心桩与角桩的沉降差值逐渐减小为零。(4)嵌岩深度小于3D时,群桩沉降量和水平位移变化较大,嵌岩深度大于5D以后,群桩沉降和水平位移分别趋于一定值。增加嵌岩深度可以有效减少群桩桩基沉降量和水平位移,嵌岩深度超过5D时,再增加嵌岩深度对群桩稳定性没有明显的改善作用。更多还原

【Abstract】 It was stated the load-bearing mechanism and settlement calculation methods about rock-socketed pile group. Taking the wharf of Naxigou project and based on establishing the ideal calculation model on rock-socketed pile group by the means of 3-d finite element numerical simulation with ABAQUS, it was carried out the analysis on the influence factors of the bearing capacity of rock-socketed pile, those factors are pile length, pile diameter, the bedrock strength, rock-socketed depth, etc. The main conclusions as follows:(1) From the results of finite element numerical simulation, it can be obtained that the vertical settlement and horizontal displacement of central pile are respectively close to that of corner pile. It was shown that the efficiency of rock-socketed pile groups is not obvious.(2) The rigid cap-pile can supports vertical load joined with piles. The stress around the cap-pile is greater than that in the middle. The load bearing by the corner pile is more than that by the central pile.(3) Under the same load conditions, the more the diameter of both central and corner piles, the smaller the settlement of pile top, and in fall the settlement curve tended to a constant. When the pile diameter is to 1.8m, the influence was weakened. The settlement of both central pile and corner pile were zero gradually.(4) When the rock-socketed depth is less than 3D, the settlement and horizontal displacement of pile group are changed more; when the rock-socketed depth is more than 5D, the settlement and horizontal displacement of pile group respectively tend to constants. Increasing rock-socketed depth can effectively reduce settlement and horizontal displacement of pile group. If rock-socketed depth gets more than 5D, increasing rock-socketed depth will have no obvious improvement to stabilize pile group.更多还原