Kinematical analysis of highway tunnel collapse using nonlinear failure criterion简

For different kinds of rocks, the collapse range of tunnel was studied in the previously published literature. However, some tunnels were buried in soils, and test data showed that the strength envelopes of the soils followed power-law failure criterion. In this work, deep buried highway tunnel with large section was taken as objective, and the basic expressions of collapse shape and region were deduced for the highway tunnels in soils, based on kinematical approach and power-law failure criterion. In order to see the effectiveness of the proposed expressions, the solutions presented in this work agree well with previous results if the nonlinear failure criterion is reduced to a linear Mohr-Coulomb failure criterion. The present results are compared with practical projects and tunnel design code. The numerical results show that the height and width of tunnel collapse are greatly affected by the nonlinear criterion for the tunnel in soil.     

工程管理专业人才培养体系探讨

人才培养是一项系统工程,需要从系统的角度合理设计人才培养的各个环节和要素。文章从培养目标的科学定位、培养内容的合理设计、培养条件的设置、培养管理协调优化,以及人才培养评价机制的建立等方面全方位地构建了工程管理专业人才培养体系,从而促使工程管理专业达到培养高素质工程管理人才的目的。     

嵌岩桩极限承载力的非线性分析

本文根据桩土之间的相互作用，采用邓肯－张模型对土、基岩进行非线性有限元分析，计算出桩、土的内力、变形以及承载力、理论计算结果与实测情况比较接近。同时据实测结果，对照规范提出建议。     

考虑孔隙水压力效应和非线性破坏准则的 浅埋地下洞室支护力上限分析

由于孔隙水压力的作用,位于饱和土体中地下结构的力学和变形特征与完全干燥土体中的结构有很大不同。根据浅埋地下洞室的非线性破坏特征构建了一个新的曲线形破坏机制,并将孔隙水压力做的功率作为一个外力功率引入极限分析上限定理的虚功率方程中,推导了孔隙水压力作用下饱和土体中浅埋洞室支护力和速度间断线上限解的解析表达式。利用变分原理,对此支护力的上限解进行了优化计算,得到了支护力的最优上限解,并对单一影响参数变化下的支护力随埋深变化规律和洞室顶部塌落面的形状进行了研究。研究结果表明：孔隙水压力对饱和土体中浅埋洞室的支护力和塌落面均有重大影响;支护力和塌落面都随孔隙水压力系数的增大而增大。     

基于非线性破坏准则和强度折减法的浅埋隧道安全系数上限解

隧道工程中常用的安全系数是一种评估隧道稳定性的有效指标。为了研究非线性破坏准则下浅埋隧道的稳定性,基于已有的直线型多块体破坏机制,采用切线法将非线性破坏准则引入上限定理的能耗计算,结合强度折减法,构建了极限状态下隧道安全系数的目标函数。采用序列二次优化迭代法对此目标函数进行优化,得到了浅埋隧道整体安全系数的上限解,并对不同参数作用下浅埋隧道安全系数的变化规律进行了研究。研究结果表明:非线性系数m对隧道安全系数和极限状态下隧道破坏面的影响十分显著。当其他参数一定时,安全系数随非线性系数m的增大而减小。极限状态下隧道破坏面随m的增大向外扩展,潜在破坏范围增大。     

Hazard development mechanism and deformation estimation of water solution mining area

1 INTRODUCTION Water solution mining-based mineral deposit belongs to the ancient landlocked evaporation of salt lake mineral deposits. The salty mineral products of mining area, such as verde salt, rock salt, glauberite, etc., mainly exist in the salty rock segment that is formed by the third sulphate sediment of group of new ditch. This rock segment consists of mudstone, anhydrite-included calcium Glauber’s salt rock, calcium Glauber’s salt rock of mudstone quality, verde salt and roc…     

小净距隧道施工方法优化研究

以河源洞小净距隧道为工程背景,通过模拟研究比较不同施工方法下的塑性区、位移、应力情况.研究结果表明:侧壁导坑法施工中对围岩开挖次数较多,围岩受到的扰动较大,塑性区范围比台阶法大;在相同的开挖次数下,CRD(中隔墙)法施工产生的塑性区范围又大于侧壁导坑法.对于围岩条件较差的情况,控制位移是施工中应该注意的一项重要工作,侧壁导坑法施工对于控制位移的增量有明显优越性,所以在软弱地层可以优先考虑采用.     

荷载变形关系求解无缝线路轨道稳定性

无缝线路是一种新型轨道结构,是轨道结构现代化的标志。无缝线路稳定性分析是无缝线路的理论基础和关键技术。国内外都非常重视无缝线路的稳定性问题,并进行了大量的试验和理论研究。运用“荷载-变形”关系进行了无缝线路轨道稳定性分析,并推导出钢轨温度力计算公式。输入不同的轨道变形波长,通过优化理论找出最小的钢轨温度力。将此模型的计算结果与不等波长无缝线路轨道稳定性计算方法所得结果进行了对比,两者较为接近,误差不超过2.07%。从而证明此方法的正确性。     

小净距隧道群掌子面间距数值分析研究

当多隧道并行且属于超小净距隧道群时,如何控制掌子面距离成为保证施工安全同时不耽误工期的一项内容.研究结果表明,掌子面之间距离越大,各隧道特别是处于最后施工并位于中间位置的二号隧道位移、应力逐渐减小,但当掌子面距离增大至一定程度时,变化就很小.综合分析,掌子面距离控制在2倍洞径较为合理.     

Slope stability analysis considering joined influences of nonlinearity and dilation

The soil masses of slopes were assumed to follow a nonlinear failure criterion and a nonassociated flow rule. The stability factors of slopes were calculated using vertical slice method based on limit analysis. The potential sliding mass was divided into a series of vertical slices as well as the traditional slice technique. Equating the external work rate to the internal energy dissipation, the optimum solutions to stability factors were determined by the nonlinear programming algorithm. From the numerical results, it is found that the present solutions agree well with previous results when the nonlinear criterion reduces to the linear criterion, and the nonassociated flow rule reduces to the associated flow rule. The stability factors decrease by 39.7% with nonlinear parameter varying from 1.0 to 3.0. Dilation and nonlinearity have significant effects on the slope stability factors. Foundation item: Project (200550) supported by the Foundation for the Author of National Excellent Doctoral Dissertation of China; Project (200631878557) supported by West Traffic of Science and Technology of China