桩承式路堤土拱效应分析的改进有限元模型  

Modified Finite-element Model to Analyze Soil Arching Effect in Piled Embankments

作　　者：杨庆年[1] 郑俊杰[2] 程科[2] 吕东杰[1] YANG Qing-nian ZHENG Jun-jie CHENG Ke LV Dong-jie(School of Civil Engineering, Nanyang Institute of Technology, Nanyang 473004, China School of Civil Engineering and Mechanics, Huazhong University of Science and Technology, Wuhan 430074, China)

机构地区：[1]南阳理工学院土木工程学院,河南南阳473004 [2]华中科技大学土木工程与力学学院,湖北武汉430074

出　　处：《土木工程与管理学报》2017年第4期19-23,38,共6页Journal of Civil Engineering and Management

基　　金：国家自然科学基金(51278216);河南省科技攻关计划项目(152102310223)

摘　　要：土拱效应在桩承式路堤中的桩土荷载分担方面具有重要作用。本文提出了一个改进的三维有限元模型来模拟土拱效应。该模型利用不同刚度的弹簧来模拟桩与桩间土,不需建立桩与土体模型,提高了计算效率。结合现场试验及其他学者提出的理论证明了模型的有效性。通过改变路堤分布荷载以及路堤填料的内摩擦角进行对比试验,数值分析结果表明,土拱存在最大、最小两个临界拱高,且不同位置的桩间土体受土拱效应影响不同。等沉面高度与土拱最大拱高并不完全一致,土拱效应的产生滞后于沉降差。在不同路堤填土内摩擦角情况下,路堤填土的应力及沉降分布基本不变,随着路堤填土内摩擦角的增大,路堤沉降有效减小。研究结果可为工程设计人员提供有益的参考。Soil arching effect plays a significant role in load distribution between the pile and subsoil. This paper proposes a modified 3D finite-element model to analyze the soil arching effect. The pile and subsoil are replaced by springs with various stiffness values. The proposed 3D model is simply implemented without pile and subsoil generation, thereby improving efficiency. Furthermore, the reasonability of the numerical model is verified by a field test and conclusions of other scholars. The contrast tests are created by changing the load and fraction angle of the embankment fill. It is found that the critical maximum and minimum heights of the soil arch can also be obtained. Subsoil of various regions are influenced by the soil arching effect in different degree. The height of the equal settlement plane is inconsistent with that of the critical arch height, so soil arching occurs after differential settlement. The stress and settlement distribution are not influenced by the friction angle. With the increase in friction angle of the embankment fill, the settlement decreases efficiently. The conclusions could be a beneficial reference for the designers.

关 键 词：土拱效应 应力分布 临界拱高 沉降差 内摩擦角 

分 类 号：U416.12[交通运输工程—道路与铁道工程]