(1 上海应用技术学院土木建筑与安全工程学院，上海 200235； 2 同济大学土木工程学院，上海 200092)
［摘要］将拉压模量不同的概念引入到桩筏基础柔度矩阵中，建立了桩筏基础简化分析模型，板单元采用基于广义协调元思想的厚薄板通用单元，解决了剪切闭锁现象；桩周土体的作用采用荷载传递法，能够考虑由于沉桩、土固结引起的有效应力变化以及桩的加载过程对荷载传递函数的影响。讨论了地基土拉压模量比对桩筏基础沉降、地基土分担比和筏板内力的影响规律。提出现有工程设计中，对于多层、小高层建筑筏板较薄的情况，不考虑拉压模量不同，会低估筏板的实际弯矩，存在安全隐患。
［关键词］桩筏基础；拉压模量；非线性共同作用；基底土反力；荷载分担比
Analysis on different modulus in tension and compression for piled rafts
Li Wei1, Zhu Cimian2(1 School of Construction and Safety Engineering, Shanghai Institute of Technology, Shanghai 200235, China;2 College of Civil Engineering, Tongji University, Shanghai 200092, China)
Abstract:Different modulus in tension and compression theory was embedded in pile foundation displacement field. A simple method was proposed for piled rafts. For solution of shear locking, the thin-thick plate element based on generalized confirming for raft was used. The soil behavior of response of individual piles nonlinearity was modeled using load-transfer function. The method was derived to simulate various factors, including effective stress changes due to pile installation and soil reconsolidation, and effects of pile loading. By examples, it further studied that the responses of foundation average settlement, foundation difference settlement, load bearing proportion, soil reaction distributing and raft internal force with the ratio of tensile modulus to compressive modulus. The calculated result indicates that the soil reaction on for medium tall building and multistory building, elastic solution tends to obtain a lower value, and internal force of raft is inexact.
Keywords:piled raft; modulus in tension and compression; nonlinear interaction; soil reaction; load bearing proportion
作者简介：李伟，博士，讲师，Emial:liwei1478@gmail.com。
参考文献
［1］POULOS H G, DAVIS E H. Pile foundation analysis and design［M］. New York: Wiley, 1980.
［2］龚晓南.油罐软粘土地基性状［D］.杭州：浙江大学，1984.
［3］王国光.拉压模量不同弹性理论解及桩基沉降计算［D］.杭州：浙江大学，2002.
［4］龙志飞，岑松.有限元法新论——原理·程序·进展［M］.北京：中国水利水电出版社，2001.