考虑沉积及应力水平的软土非线性沉降预测和临界点分析  

Nonlinear Settlement Prediction and Analysis of Critical Point for Soft Soil Considering Sedimentation and Stress Level

作　　者：李娟燕 耿大新[2] 金超奇 丁海滨 管凌霄 LI Juan-yan;GENG Da-xin;JIN Chao-qi;DING Hai-bin;GUAN Ling-xiao(Jiangxi Vocational Transportation College of Communications,Nanchang 330200,China;School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang 330013,China)

机构地区：[1]江西交通职业技术学院,南昌市330200 [2]华东交通大学土木建筑学院,南昌市330013

出　　处：《公路》2025年第4期26-35,共10页Highway

基　　金：国家重点研发计划资助项目,项目编号2023YFC3009400。

摘　　要：综合考虑了土体的结构性、有效应力和沉积作用等非线性因素,基于单对数统一模型,推导了土体压缩模量和沉降预测的非线性计算方法,并结合工程案例与其他预测模型进行对比验证。结合宁波软土地区上百份地勘固结试验,基于该模型针对饱和软土(淤泥质土及黏性土)展开分析,确定了土体非线性触发的临界条件,即有效应力和沉积作用非线性触发的临界条件。除此之外,探究了土体的自重应力、压缩模量及沉降的演化规律。结果表明:自重应力和压缩模量随深度呈非线性变化,当计算深度大于10 m时,需要开始考虑土体应力水平的非线性行为;淤泥质土的埋深大于48~50 m或层厚大于6~10 m的情况下,以及黏性土埋深大于44~46 m或层厚大于13 m的情况下,还需要进一步考虑沉积作用的非线性行为;当附加应力较小时,压缩模量主要受前期固结应力的影响,随着附加应力的不断增加,附加应力对压缩模量的影响也不断变大。Considering the nonlinear factors such as soil structure,effective stress and sedimentation,the nonlinear calculation method of soil compression modulus and settlement prediction is derived based on the single logarithmic unified model.The reliability of the model is verified by engineering examples,and the evolution law of soil self-weight stress,compression modulus and settlement is explored.Based on this model and combined with hundreds of geological exploration and consolidation tests in Ningbo area,the critical conditions for nonlinear triggering of saturated soft soil(silty soil and cohesive soila)re determined,that is,the critical conditions for nonlinear triggering of effective stress and sedimentation.The results show that the self-weight stress and compression modulus change nonlinear with depth.When the depth is greater than 1o m,the nonlinear behavior of soil stress level should be considered.When the buried depth of silt is greater than 48~50 m or the layer thickness is greater than 6~10 m,and the buried depth of clay is greater than 44~46 m or the layer thickness is greater than 13m,the nonlinear behavior of sedimentation should be further considered.When the additional stress is small,the compressive modulus is mainly affected by the pre-consolidation stress.With the increasing of the additional'stress,the influence of the additional stress on the compressive modulus is also increasing.

关 键 词：地基沉降 单对数统一模型 应力历史 沉积作用 非线性 土体沉降 

分 类 号：U419.8[交通运输工程—道路与铁道工程] TU447[建筑科学—岩土工程]