桩基冻胀力三维问题的积分方程解法

利用叠加原理和弹性半空间的Ｍｉｎｄｌｉｎ公式，导出了计算桩基冻胀力三维问题的积分方程。用该积分方程可计算不可压缩和可压缩的桩基冻胀力，文末给出一算例，算例表明该理论结果和实测结果吻合良好     

混凝土结构裂缝修补技术

介绍使用环氧树脂胶液修补混凝土结构裂缝的施工要求及方法。     

营业线施工应增加有关概算费用的探讨

针对目前铁道部有关加强行车安全的文件与设计概算编制规定不协调的问题,笔者提出了自己的看法.     

Analysis on the Effects of Overloading on the Mechanical Properties of Tunnel Structures in the Silty Ground --A Case Study of Sutong River-crossing GIL Utility Tunnel北大核心CSCD

Based on the Sutong GIL utility tunnel project, which is constructed by the shield machine under the river, and as for the overloading problem at the river bank slope during operating period, the refined threedimensional finite element model was established to study the deformation and cracking characteristics of the tunnel segment structure under different forms of overloading. The evolution laws of section convergence, joint opening and structural stress were analyzed, and the structure damage mechanisms were revealed under conditions of large area loading and local loading. The surface-surcharge control standard was proposed. For the big diameter shield tunneling crossing the silty clay, the research results show that: (1) the deformation failure process is divided into three stages under large area loading condition, taking the design load and compressive yield of rebars inside haunch as the critical points respectively. The first stage is characterized by the elastic stress, the second stage is in plastic state with fracture, and the third stage is accelerating deformation and instability stage. The vertical convergence is 110.5 mm with no opening of joints when rebars are yielded; (2)the deformation failure process under local loading condition is also divided into elasticity, plasticity and instability stages, taking the design load and tensile yield of rebars outside haunch as the critical points respectively. The vertical convergence is 152.6 mm with joint opening of 4.36 mm; (3) the early-warning values of additional stress on the ground under conditions of large area loading and local loading are 110 kPa and 70 kPa respectively. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

汽车悬架球铰总成二维动态试验台开发

汽车悬架及转向球铰总成的可靠性直接影响汽车行驶的操控性、乘坐舒适性及安全性,其承受的载荷是由多方向脉动拉压和旋转等共同作用产生的复合作用载荷,因此,试验台的设计是近似模拟球铰的实际栽荷工况进行的二维动态试验,以使试验效果能更真实地反映球铰的使用可靠性.结果表明,研制的二维动态试验台能够达到设计要求,满足整车操控性能、乘座舒适性及行驶安全性,在产品的设计和质量保证上得到了验证.     

REPORT OF HLA DISTRIBUTION IN 2315 VOLUNTEER DONORS OF CHINESE BONE MARROW BANK FROM NORTHWEST CHINA

HumanLeukocyteAntigen(HLA)system, knownashumanmajorhistocompatibilitycomplex (MHC),playsakeyroleinantigenprocessing,im muneregulationandotheraspects.HLAisalsobeen calledastransplantingantigenasaccuratetypingof HLAonbothpatientanddonorcanincreasedramat i…     

低地板轻轫车辆车体连接铰强度分析

根据5节编组的100%低地板轻轨车辆连接铰型式和受力特点,建立了车体的静力平衡方程组,推导出了连接铰受力的解析表达式.采用EN 12663规范,使用有限元分析软件,校核了固定铰上铰的静强度和疲劳强度.