膨胀岩巷道膨胀失稳破坏过程分析及注浆支护参数确定

膨胀岩是一种亲水的、且会产生显著变形的工程岩体．注浆是控制此类岩体巷道变形的主要工程措施，选择合理的注浆参数成为此类岩体工程支护成功的关键因素．对膨胀岩工程巷道失稳破坏过程进行了分析．在确定膨胀岩膨胀应变与膨胀应力、吸水量关系的基础上，研究了具有简化膨胀模型的圆形膨胀岩巷道的注浆效果，得出了各主要注浆参数的计算公式．     

松散破碎围岩锚注在返修巷道中的研究应用

通过对锚注支护机理的阐述,研究锚注支护修复巷道的可行性。结合丁集矿典型返修巷道变形与破坏形式特征,设计该返修巷道锚注支护方案,并完成了现场监测分析与评价。实践表明,该技术是解决深井高应力软岩返修巷道支护的有效途径,具有较高的推广应用价值。     

视频检测技术在城市隧道中的应用

视频检测技术是目前城市隧道新的交通数据检测手段之一。介绍了视频检测技术的工作原理和特性,并针对杭州新城隧道工程实例阐述了视频检测的主要构成部分、隧道内车辆统计和定位、事件管理、车辆拥挤控制和实时监视的应用,使得城市隧道管理部门能够在极短的时间内作出响应并采取必要措施,确保城市隧道交通安全及畅通,为城市隧道智能交通管理提供了新的技术手段。     

厦门海底隧道围岩-支护系统相互作用时效数值分析

考虑厦门海底隧道F4风化囊区段岩体的流变作用,采用有限元软件ANSYS对围岩-支护系统相互作用的时效特征作了数值分析.分析中主要计及支护时间和支护厚度这两个因素,分别得到不同支护时间和不同支护厚度下围岩与衬砌的应力、变形及其时间效应.为厦门海底隧道合理选择支护厚度和支护设置时间提供参考.     

The effect of surroundings with different separation distances on surface pressures on low-rise buildings

Very large roof suctions on low-rise buildings occur for isolated buildings during both full-scale experiments and wind tunnel tests performed by many investigators. This paper investigates the sensitivity of these high suctions to the presence of multiple surrounding building configurations. This study uses the Wind Engineering Research Field Laboratory (WERFL) building studied during the CSU/TTU Cooperative Program in Wind Engineering as a basic building shape. A model of the WERFL structure was constructed to a 1:50 scale and instrumented with multiple pressure ports. Pressure taps on the 1:50 scale building model were connected to two 48-channel PSI transducer units. A large number of “dummy” models of similar dimensions were constructed to represent surrounding buildings. These model buildings were arranged in various symmetric configurations with different separation distances, and placed in the Industrial Wind Tunnel of the Wind Engineering and Fluids Laboratory, Colorado State University. Measurements include mean, RMS and peak pressures, street canyon velocity profiles and laser-sheet flow visualizations. Shelter effects produced by the surrounding buildings on the central instrumented building were found to be significant, such that flow patterns are displaced and mean and peak induced loads are significantly different from the isolated building base case. The surface pressures of master WERFL model inside the urban street canyons were determined by the prognostic model FLUENT using the four differences closure approximation and FDS, large eddy simulations methodology. Calculations are compared against fluid modeling from wind-tunnel test.     

DYNAMICS OF SEDIMENT-ASSOCIATED METALS IN A HIGHLY URBANISED CATCHMENT: BRADFORD, WEST YORKSHIRE

Urban watercourses are potential hazards because of their rapid flow changes, poor water quality and contaminated sediments. This study is a preliminary field investigation into fine sediment-associated metal contamination and its transport dynamics in a highly urbanised catchment in West Yorkshire, UK. Spatial and temporal changes in the concentration of channel-bed sediment-associated metals are investigated, and the fluxes of selected suspended sediment-associated metals, during an extreme high flow event, are determined. Channel-bed sediments were more contaminated at the most heavily urbanised sites. Data suggest that contaminated bed sediments could accumulate and possibly become increasingly contaminated between high-flow events, prior to being flushed from the system. Fluxes of contaminated suspended sediments were very high at the peak of the high flow event. The spatial and temporal dynamics of contaminated fine sediment which were identified in this study could inform planners with regard to future monitoring strategies.     

盾构壁后注浆体变形及压力消散特性试验研究

壁后注浆是盾构施工的关键工序.壁后注浆体的变形及力学性质变化直接影响到土体的应力释放、地层位移及作用在管片上的土压力大小.利用自制壁后注浆单元体模型试验装置,研究不同的注浆压力、注浆材料及围岩土质条件对注浆体变形及注浆压力消散的影响规律.较高的注浆压力有利于减小围岩的应力释放量,加快浆体排水速率.在砂性土地层中,浆体变形和浆体压力消散较粘性地层快,说明土质条件对地层位移和围岩应力释放影响较大.     

砂层中地铁暗挖隧道施工技术研究

沈阳地铁青年大街站-怀远门站区间隧道主体结构全部位于中粗砂、砂砾层中,结构底板埋深23·5~17·5m,砂层由于其不稳定性、极强的透水性,对地铁暗挖施工提出了很高的要求。该文主要阐述地铁区间隧道的施工方法及砂层的加固处理措施,对沈阳地铁的暗挖施工技术提出相关的意见与建议。     

复杂型体悬挑屋盖风荷载风洞试验与数值模拟

基于Fluent 6.1软件平台,将Realizablek-ε模型与非平衡壁面函数搭配使用,对位于海岛强台风地区的某海洋文化中心屋盖风压分布进行了计算流体动力学(CFD)数值模拟,同时也对该建筑进行了风洞试验。模拟结果与风洞试验数据的对比显示数值模拟可较准确地反映实际风压。风洞试验和数值模拟均显示悬挑屋盖受到了很大的吸力,对屋盖结构极为不利,对此问题采取在屋盖悬挑部分开洞的减压措施,以改善屋盖悬挑部分的受风特性。对开洞后的建筑进行了CFD建模与计算,结果表明在屋面前缘开洞可有效降低屋盖悬挑部分的最大风压和所受的竖向升力,大大改善屋盖结构的受力状态。