集料含水率对混凝土配合比的影响

集料含水率对于混凝土水胶比波动有十分重要的影响,砂石料中水含量变化将会影响设计配合比在施工中的实现。文章对苏通大桥集料的含水率进行测定,研究典型天气条件下含水量分布和变化情况,提出调整不同天气条件下砂石料含水率方法。     

劲性水泥土搅拌连续墙在天津地铁改建工程中的应用

劲性水泥土搅拌连续墙(SMW)作为排桩和板墙式围护结构的一种,以其适用性强、围护成本相对较低、施工周期短而倍受关注。天津市地铁1号线工程西北角—西南角既有区间隧道改建工程的围护结构施工中采用了该技术,并取得了良好的效果。     

铁路货车新型Leila转向架

介绍了铁路货车新型Leila转向架的结构,以及优良的性能.     

南京地铁车辆合成闸瓦技术方案探讨

分析了国内外铁路车辆应用的合成闸瓦技术,并对地铁车辆使用的合成闸瓦特点进行探讨.提出研究聚合物基复合摩阻材料的地铁车辆合成闸瓦初步技术方案,重点解决适用于地铁车辆制动工况的关键技术,包括耐热高聚物的改性和应用研究、增强材料的应用研究和设计材料结构与性能,并对合成闸瓦的生产工艺进行初步探讨.     

基于UG二次开发的DTS名义值测量

文章主要介绍基于UG二次开发的DTS名义值测量,本系统基于西门子的先进CAD设计平台NX之上开发的系统。以NX11和Visual Studio 2010作为运行和开发平台的,C、C++为开发语言,使用Block UI Styler为界面设计工具,NXOpen则提供了开发所需的应用程序包(API)。系统可以通过获取整车FVML(Finish Vehicle Measurement Location)文件包含的信息,通过用户选择文档中对应的零件特征,实现自动测量数模名义值及对应截面,并与FVML定义的数值进行对比。     

桥墩防撞装置碰撞动力学分析

运用非线性有限元基本理论，采用国际上广泛使用的大型结构分析程序LS-DYNA，建立了船舶和桥墩防护装置的三维有限元计算模型，分析了防护装置碰撞特点、船首及构件的损伤和吸能特性，得出了主要吸能结构吸能比例，碰撞力曲线的非线性特点，船体和防撞装置外板是主要的吸能结构等结论．     

Analysis on the Characteristics and Development Trends of the Support Technology of High Ground Stress Tunnels in China北大核心CSCD

Combining the present situation and development trend of different tunnel support technologies at home and abroad, this paper analyzes the problems of rockburst in hard rock tunnels and large deformation in soft rock tunnels caused by high ground stress. It is concluded that: 1) regarding the rockburst problem, the current support technology is mainly influenced by the rock burst mechanism which is dominated by static factors, and so the used support components are generally of smaller deformation performance and "passive support" properties; 2) as the rockburst is the result of dynamic-static stress coupling, and only the anchor bolt has the "active support" attribute in the current "shotcrete+anchor bolt+wire net" support system, so the best support system should have the two functions of active support and energy release in terms of the rockburst problem, and the key focus of the research and development is anchorage members; 3) there are three main support types for large deformation in soft rock tunnels, e.g. the heavy support, layered support and yielding support. Among them, the heavy support system in underground cavern with large deformation is easy to induce excessive surrounding rock pressure, and so the applicable conditions are limited. The layered support system is still not the best choice due to its immature theoretical study, difficult determination of the thickness value and the installation time of each support layer and the interference to construction progress. With the characteristics of timely support and yielding while supporting, the yielding support system can give full play to the performance values of surrounding rocks and supporting materials, and make both of them reach the optimal state, so it is the best choice for supporting the soft rock tunnels with large deformations. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

Numerical Simulation of Advanced Geological Forecasting Based on Multi- Source Seismic Interferometry北大核心CSCD

For existing advanced geological forecasting, the forecast distance is short and the test frequency is high, increasing test and construction risks. Since various methods have different requirements for the test environ-ment, preparation work can be tedious and result in a long construction time thereby affecting normal construction.A new advanced geological forecast technique based on multi-source seismic interferometry for tunnels is proposed.This technique uses the blast at one end of tunnel as a centrum and receives the signal at the other end of the tun-nel, therefore allowing advanced geological forecasting of the unexcavated tunnel part by relative processing and im-aging. A numerical simulation of this kind of geological forecasting using the finite difference method to simulate two kinds of unfavorable geological bodies (karst and a fault) predicted them accurately and verified the effective-ness and accuracy of this geological forecasting method. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

Experimental Study on Mechanical Behaviors of Prefabricated Column-Base Joint with Grouted Sleeves Connecting Longitudinal Reinforcements in Tunnels北大核心CSCD

In recent years, large shield tunnels with internal double-decked lanes have been developing rapidly in the field of highway tunnels, and prefabricated elements are increasingly adopted in internal structure. Based on the columns-base joint in Zhuguanglu tunnel, which is under construction, 2 full-scale specimens are designed for the quasi-static test, one specimen is connected with grout sleeve splicing and the other is cast in place. The test results show that: the bearing capacity of specimen with grout sleeve splicing is equal to that of cast-in-situ specimen, but its ductility and energy dissipation capacity are worse than that of the cast-in-situ specimen. And for the specimen with grout sleeve splicing, there exists crack concentration on the area above the sleeve. The crack width is too larger in this area. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.