嵩厦220kV送电线路海上N9铁塔冲(钻)孔桩施工技术

论述嵩厦 2 2 0kV送电线路海上N9铁塔若干重要环节施工问题 ,对同类工程施工提出几点建议     

杭州地铁盾构施工中地表位移及变化规律研究

杭州地铁盾构施工多处在淤泥、淤泥质土等软土层中。在实测数据的基础上,分析了地铁盾构施工地表沉降在纵向和横向上的变化规律、沉降范围以及沉降槽宽度系数和最大沉降量与隧道埋深间的关系。分析结果表明,地表沉降根据沉降大小和盾构机头的位置在轴线方向上分三个阶段,即盾构机到达前0～40 m、到达后0～50 m和后盾构等三个阶段。以盾构机头为中心,地表沉降的纵向影响范围为前40 m、后50 m,横向上为左右两侧各20 m。盾构施工期间地表位移主要表现为沉降,但也有隆起,盾构到达后的20～50 m为沉降发生的主要阶段,后盾构阶段沉降稳定,但也存在部分回弹现象。沉降槽宽度系数随着埋深的增加影响范围增大,而地表最大沉降量则随着埋深的增加减小。文中得到的结论对于杭州等软土地区地铁盾构施工、监测和设计等具有一定的指导作用和理论意义。     

Surface settlement caused by twin-parallel shield tunnelling in sandy cobble strata

City metro tunnels are usually constructed as twin-parallel tunnels and their adjacent construction may lead to surface deformation, affecting the surface environment and the safety of the tunnels. Due to its strong dispersion, sandy cobble strata can be easily disturbed by shield tunneling. Based on the project of the Chengdu Metro Line 1, field and model tests were carried out to study the surface settlement caused by shield tunneling in sandy cobble strata by measuring surface settlement curves, ground loss ratios and construction influence zones. The discrete element method (DEM) was used to study the factors affecting the formation of ground arches in sandy cobble strata at the microscopic level. Results show that the shape of the surface settlement curve in sandy cobble strata is different from that in soft soil. The buried depth and clear spacing of the two tunnels had a significant impact on the formation of ground arches.     

盾构开挖顶推力对下平行隧道影响的数值分析

以滨海软土地层中盾构隧道平行上穿既有隧道为背景,通过数值仿真软件对开挖动态过程进行了精细化模拟,研究盾构隧道施工顶推力对周边地层及其内部既有隧道受力变形的影响。结果表明,在新建隧道上穿施工过程中,开挖扰动对地层的影响范围主要集中在距离开挖面-1.0~1.5D区域内(D为盾构隧道外径),扰动效果以新建隧道轴线为中心呈环状向外扩散,盾构顶推力从0.1MPa增至0.4MPa时,地表变形及1.0D范围内地层压力均增大20%以上;新建隧道平行上穿既有隧道过程中,既有隧道断面变形从横向鼓曲变为竖向拉伸,且整体出现上浮现象,顶推力达0.3MPa后,既有隧道拱底和拱顶隆起速度增加,以拱底为基准,顶推力自0.1MPa增加至0.4MPa时,隧道上浮量增大34.2%;施工过程中除保证常规地表变形监测外,对于近接平行上穿施工还需加强对既有隧道竖向变形的监控,必要时采取结构加固措施和施工参数综合调整办法,以降低开挖扰动对周边地层和结构物的影响。     

浅谈电子电路的抗干扰技术

通过分析影响电子电路工作性能的干扰现象和产生干扰的根源,给出了抑制干扰原理及相应的抗干扰措施.     

盾构隧道穿越铁路群的施工应用

结合广州市轨道交通三号线盾构隧道穿越广深铁路轨道群的施工实际经验,介绍了所采用的土压平衡盾构施工技术,并指出了常见问题及其对策和预防措施,对类似的地质条件下跨地铁段的设计和施工有一定的参考价值.     

盾构位姿测量方法的研究

在地下暗挖施工过程中,盾构机的掘进路线必须在设计误差要求范围内,因此实时监控盾构的运动状态至关重要。作为盾构机眼睛的导向系统要求高精度、实时快速地测量出盾构的位置和姿态。基于嵌入式技术设计的激光位移检测靶主要由CCD照相机、倾角传感器和棱镜等光学元件组成,结合全站仪和后视棱镜,通过CCD采集全站仪发射的激光光斑,对光斑图像进行去噪、形态学等处理,准确计算中心点坐标,通过坐标系的转换,最终实现对盾构的滚动角、方位角和俯仰角的测量。     

屏蔽Authorware程序中的"当"声

利用A5wmme.u32函数检测MIDI设备错误情况以及屏蔽错误信息窗口.     

论盾构施工穿越既有地铁运营线路的控制措施

中-松盾构区间上跨既有崇岐运营线路区间施工难点是两线间距小、始发段长度较短,施工中通过将盾构机选型、掘进参数控制、刀盘前方渣土改良以及既有线和新建线路的监控量测等措施相结合,达到盾构施工通过既有线的目的,为其他类似工程施工提供借鉴意义。     

Test and numerical analysis on performance of reinforced concrete segment in subway tunnel

To investigate the mechanical behavior of segmental lining,a three-dimensional numerical analysis and test using three actual segments were used to analyze the effects of axial force and reinforcement ratio on the failure mechanism and ultimate bearing capacity of segmental lining.Both numerical and test results confirmed that the cracking load,yield and ultimate load were strongly influenced by axial force,and it was also proved that the yield and ultimate load would increase with the increase of reinforcement ratio,but the cracking load was almost not affected.The cracking load,yield and ultimate load are about 28.7%,500% and 460% larger due to the effect of axial force respectively.The comparison between numerical calculation and test results showed that the finite element analysis results were in good agreement with the test results.