【作者】 王丙兴；

【导师】 姜忻良；

【作者基本信息】 天津大学 ， 结构工程， 2012， 博士

【摘要】 在软土上填筑路基往往会发生较大的沉降不均匀沉降及边坡失稳ˊ影响着高速公路行车安全及舒适度本文应用反演理论ABAQUS有限元分析软件对软土路基沉降进行预测ˊ并引入非概率可靠度理论用来评价沉降预测值的可靠性同时对软基边坡失稳进行可靠性研究主要研究工作如下1考虑软土结构性损伤对沉降变形的影响ˊ应用反分析理论对软土路基沉降进行了预测2利用ABAQUS有限元分析软件ˊ计算并分析软土路基沉降ˊ应用非概率可靠性研究方法对软土路基沉降可靠度进行分析ˊ计算沉降的可靠度指标ˊ从而为软土路基沉降提供一种有效地分析方法3应用盲数测度理论对某高速全路段的路基力学性能指标参数进行了分析ˊ计算出了基于盲数测度理论确定的参数代表值区间ˊ并与ǎ岩土工程勘察规范规定的参数确定方法相比较ˊ验证了其合理性4应用基于区间分析可靠度模型对软土路基沉降进行可靠度分析ˊ并与实际工程相结合ˊ从而验证了非概率可靠性模型在路基沉降可靠度分析中的可行性并通过参数变化的对比分析ˊ确定了沉降可靠性指标对不同参数的敏感性5采用Mohr-Coulomb屈服准则ˊ将可靠度理论与有限元强度折减法计算出的中值安全系数进行耦合ˊ在考虑了土体的弹塑性本构关系和塑性应变对安全系数的影响情况下ˊ分析了土体强度在折减下的塑性应变与位移的变化关系ˊ提出根据塑性应变或位移的突变(陡增)判断土质滑坡稳定性失效的方法更多还原

【Abstract】 Soft Ground subsidence differential settlement and slope instability affected the traffic safety and comfortable of Expressway. We forecast the settlement of soft ground used the back analysis method and ABAQUS finite element software, the introduction of non-probabilistic reliability theory to evaluate the reliability of predictions; Simultaneity we study the reliability of slope instability;the main works are as follows:1 Forecasting the settlement of soft ground used the back analysis method considering structural damnification of soft soil.2 Calculating and analyzing the settlement of soft ground used ABAQUS finite element software, introducing the non-probabilistic reliability theory to evaluate the reliability of predictionsˊthus we find an new method of forecasting the settlement of soft ground.3 Using blind number theory to analyse the mechanical index of the soft ground, figuring out the Interval of parameter delegate, and comparing with the method calculating parameter based on <Specification for geotechnical investigation>, validating the rationality of the method.4 Using reliability model based on interval analysis to analyze reliability of soft soil subgrade settlement and combine with practical project. It proved that using non-probabilistic reliability model to analyze reliability is possible. Through the comparison of parameter change, it determined the sensitivity of settlement reliability index to different parameter.5 Using Mohr-Coulomb yield criterion, and coupling median safety factor based on reliability theory and finite element strength reduction method. Considering the effect to safety factors caused by elastic-plastic constitutive relation of soil and plastic strain, this paper analyze the soil strength plastic strain and displacement under the reduction condition, and proposed a method to judge soil slope stability failure based on plastic strain and displacement mutation.更多还原