岩土工程下沉贯入数值模拟方法研究进展

岩土工程下沉贯入领域的数值分析,由于结构物贯入时网格变形过大而产生扭曲畸变等问题,常会造成收敛困难甚至计算结果失真.采用合适的数值方法分析此类问题颇具挑战性.本文系统介绍了近年来对于岩土下沉贯入数值模拟的研究现状和发展动态,对各种数值模拟方法的相关原理、主要特征以及优缺点进行简要的探讨.并简要介绍耦合的欧拉-拉格朗日(coupled Eulerian--Lagrangian,CEL)有限元法的基本原理,通过不排水条件下的条形基础贯入问题和砂土中桩的静压下沉示例分析,表明CEL有限元法在模拟岩土贯入问题时计算结果的准确性和较其他模拟方法的优势.文中所阐述的岩土贯入分析数值模拟方法可供从事岩土贯入分析的相关学者借鉴参考.     

防止温度应力下海底管线发生整体屈曲的工程措施研究

为减小油气输送难度和避免原油固化,石油、天然气通常在高温高压下输送.输送过程中的高温和高压导致海底管线中产生较大的附加应力,附加应力的不断累积造成管线发生整体屈曲.对于埋地的海底管线通常会产生竖向屈曲大变形而影响使用甚至破坏.因此,需对有可能产生整体屈曲的管线采取工程防护措施.结合我国海洋工程中管线常用的铺设及保护措施,对处于保护状态下管线由温度应力引起的整体屈曲特性进行理论分析和数值推导,对沟槽保护、沟槽掩埋保护以及压块保护措施的有效性进行了系统分析和对比.     

An FE analysis of reinforced subgrade under automobile loading

An FE analysis procedure was presented to predict the behavior of soil-geogrid interaction under automobile loading. The dynamic interactions between the transverse bars, the longitudinal ribs and the soil were simulated by a system consisting of nonlinear springs, dashpots and masses, to study the deformation properties of the reinforced soil. The equivalent stiffness and damping ratios could be determined with the shaking table. The dynamic responses of a reinforce subgrade were analyzed with the 3D finite element approach. This approach is programmed and applied to analyze the soil-geogrid interaction under dynamic loading. The comparative analysis of the response of the reinforced subgrade and that of the subgrade without reinforcement shows that the geogrid placed at the bottom of the base layer may effectively reduce the accumulative plastic deformation due to the cyclic automobile loading.     

用爆破挤淤法处理陆上软基

研究了爆破挤淤法在陆上应用的机理；基于土力学与爆炸力学的基本理论，得出了能反映布药参数与淤泥参数的用药量公式；结合现场试验，给出了陆上爆破挤淤法的施工工艺和检测方法，并就试验过程中出现的现象进行分析；检测结果表明，爆破挤淤技术可以满足特殊条件下软基处理要求。