碎石桩复合地基若干问题的理论分析

由桩-土侧向变形及竖向变形协调条件，基于弹性理论导出了桩及桩周土的应力-应变关系、桩体材料屈服时桩-土应力比的计算式．推出了桩周土处于极限平衡状态下，碎石桩极限承载力计算式．指出了用碎石桩加固软土地基效果比较明显．但用碎石桩来加固土的变形模量大于8MPa的地基，加固效果十分有限．最后，通过工程实例，将计算结果与实验结果作了对比．

THEORETICAL ANALYSIS OF SOME PROBLEMS ABOUT THE COMPOSITE FOUNDATION OF GRAVEL PILES

In this paper, the relationship between the stress-strain of the piles and the soil nearby based on the horizontai and verticai deformations between them is de-rived under the linear elastic conditions. The formula of the pile-soil stress ratio at the yield point of the pile is obtained. Meantime the ultimate bearing capacity of the gravel piles is derived under the ultimate equilibrium state. It is shown that the reinforcement by the gravel piles in the weak ground is significant. But for the ground deformation modulus over 8 MPa, the reinforcement is not significant. At last the results in this paper are compared with the test in an engineering example.