中文摘要：

利用有限元分析软件ANSYS建立长短桩复合地基数值模型,探索了垫层厚度变化对长短桩复合地基中长桩与短桩中角桩、边桩和中桩的沉降和应力特性的影响,得出如下结论：随着垫层厚度的增大,长桩桩体沉降也随之减小,短桩各桩体的沉降最大沉降值都出现在垫层厚度为0.15 m时,并且在各种情况下短桩各桩体的沉降基本一致;长桩各桩体的应力值随着垫层厚度的增大随之降低,但变化越来越不明显,尤其是厚度在0.3 m～1.0 m之间,基本没有变化。通过实际工程结合数值模型分析结果表明,垫层厚度的最经济值应该取0.3 m～0.6 m之间。

英文摘要：

By using the finite element analysis software ANSYS to establish the numerical model of long-short-pile composite foundation,the influence of cushion thickness variation on the settlement and stress characteristics of the corner pile,side pile and center pile in long-short-pile composite foundation is researched here in detail.The analysis results show that with the cushion thickness increasing,the settlement of long pile also decreases,when the cushion thickness is 0.15 m,the maximum settlement of short pile appears,and in various cases,the settlement values of short pile are general in agreement;With the cushion thickness increasing,the stress value of long pile decreases,but the change is less and less obvious,especially when the thickness is from 0.3 m to 1.0 m,there is no change.Combined practical engineering with numerical model analysis,it is shown that the most economic value of cushion thickness should be between 0.3 m to 0.6 m.