某近距离小尺寸基坑开挖与桩基施工对地铁车站结构的影响研究分析

基于某落客平台搭建前需在紧邻广州地铁九号线地铁车站结构位置开挖承台基坑、施工桩基础的实际工程案例,本文采用岩土三维模拟分析软件Midas-GTS NX对实际施工工况进行模拟计算分析,得到一些初步结论,为轨道交通建设和保护提供参考借鉴。     

基于X-steel的海洋结构物的重量控制

自升式钻井平台和大型导管架拖拉装船,钻井平台的下水和平衡实验,以及大型导管架海上安装的特殊要求,都对重量和重心提出了严格的要求。本文以自升式钻井平台和大型导管架的重量控制为例,简要的阐述重量控制的流程,以及在X-steel软件辅助下,获得海洋结构的重量和重心的方法。     

A高层建筑与重庆轨道交通近接施工数值模拟分析

A高层建筑位于重庆市轨道环线、九号线支线的地铁线路保护线内,并且先于地铁修建,该高层建筑的设计方案需要考虑今后轨道环线、九号线支线施工对其自身的影响。文章采用三维弹塑性有限元方法,通过模拟轨道环线、九号线支线隧道施工,对A高层建筑因隧道施工产生的位移影响进行预测。计算结果表明,A高层建筑采用桩基础结构形式,可以很好地限制A高层建筑因隧道开挖产生的变形和释放的围岩荷载;该高层建筑不会对轨道环线、九号线支线隧道的结构内力产生太大影响,因而隧道衬砌不需要再进行加固设计。这一结论为该工程的顺利实施提供了理论依据。     

海洋钻井平台井架安装工艺探讨

随着海洋石油开发节奏的加快,我国海洋钻井平台的建造数量不断增加。钻前公司作为专业化的陆地钻机井架安装施工队伍,近年来不断加大了海洋钻井平台井架安装施工市场的开拓力度,作业施工量逐年增加。由于海洋钻井平台特殊的作业环境、较高的安全要求、高质量要求等原因,海洋平台井架与陆地井架在结构、质量要求、施工要求等方面存在很大的不同,对现场施工带来了较大的难度。本文结合多年的海洋钻井平台井架的安装施工经验,对海洋井架的现场施工安装、质量控制、技术难点等内容进行了研究,力求下一步的技术改进和市场开拓提供技术借鉴和指导。     

海洋平台钻井帽吊机改造优化方案

对海洋平台钻井帽吊机改造的重难点进行了分析,研究了履带吊的参数、平台具体方案及履带吊组装与拆卸等作业方法,以期通过对海洋平台钻井帽吊机的优化改造,实现吊装作业的顺利进行。     

四川页岩气钻井及压裂作业边界噪声调查与分析

简要分析了四川页岩气勘探钻井现状，监测了单、双平台钻井作业和压裂作业边界噪声。监测结 果表明：压裂作业边界昼间噪声平均值高于单、双平台钻井作业平均值约10dB（A），噪声测量值的最低值和最 高值相应高出4～6dB（A），昼间噪声超标率高于钻井作业，说明压裂作业噪声对周边的影响远超过钻井作业； 相对于单平台，双平台发声设备多，造成声叠加影响严重，高发声设备在同一方位声叠加更显著。通过噪声值 对比，提出页岩气勘探钻井过程可考虑选取噪声更小的气代油或电代油动力设备、建立隔音设备、根据地形与 噪声传播规律调整声源设备摆放位置等降噪措施。     

烟囱锈蚀的钢爬梯及平台高空置换施工技术

浙江巨化热电九号机组钢筋混凝土烟囱钢爬梯及平台因受外部环境的影响而锈蚀,为保证正常使用,将锈蚀的钢爬梯及平台采用高空置换,取得了较好的效果。     

综合地面电磁法在川南页岩气钻井上部井身结构优化中的运用

在岩溶、地质灾害发育地区,页岩气钻井过程中,地表至地下1000m深度,出现恶性井漏、掉钻、水侵、垮塌、水源污染等事故频繁,为防止以上事故发生,不同浅表地质条件的钻井平台应具有针对性的井身结构。本文以川南宜宾长宁页岩气勘探区块为例,主要介绍了高密度电法及音频大地电磁法的综合地面电磁法在钻井上部井身结构简化和加固优化中的运用情况及效果,在预防钻井事故和地下水污染以及节省钻井费用等方面起到了重要的技术支撑作用。     

军用梁平台在城市地铁施工中的应用

以北京地铁九号线丰台东大街站为依托,通过分析军用梁的理论知识,对军用梁的设计进行了验算说明,并对军用梁拼装、现场安装、平台系安装、监控量测等施工工艺进行了详细阐述,为类似工程施工积累了经验。     

提高海洋石油钻井平台电气设备安全性的措施

海洋石油资源的勘探需要依靠海洋石油钻井平台。但海洋石油钻井平台的使用是有一定危险性的,因为周边易燃物品多,容易引发火灾。论文分析钻井平台电气设备的使用特点,探讨防爆电气设备使用中会存在的隐患,并提出相应的完善措施,以供参考。     

锥体结构的冰激振动与冰力函数

基于现场原型结构测量 ,研究了冰与锥体结构相互作用的动冰力与冰激锥体结构振动 ,建立了确定性冰力函数。实测发现 ,冰与锥体结构作用时以弯曲破坏为主 ,冰的破碎长度与冰厚成正比 ,冰的破碎频率随冰速增加 ,并有可能达到结构的固有频率。通过分析冰的破坏过程与冰压力盒测量的冰力时程 ,建立了三参数的冰力函数 ,并讨论了各参数的影响因素     

Model test study for ice force on the bank-head of the lead-navigating bank

To determine the bank-head’s ice force of the lead-navigating bank at key position that faces the ice directly of certain water conservancy, ice model test in reduced scale is designed and carried out based on the local situation on the spot and data observed. Preliminary conclusions are got through the analysis of the experimental data such as effect of the ice velocity on the ice force, ratio of components of forces when ice sheet acting on the vertical bank-head, ice force ratio of vertical to 45° incline as well as ratio of level ice force to the vertical ice force when acting on 45° incline. Finally, suggestions on determination of the ice force using formula are given after comparison between the result calculated by the present formula of ice force and the experimental results. Translated from Journal of Tianjin University (Natural Science), 2006, 39(5): 537–542 [译自: 天津大学学报 (自然版)]     

Laboratory tests for dynamic ice-structure interaction

The CRREL test basin is able to simulate dynamic ice-structure interaction with scale model tests which cover the whole range of structures that are considered here. For bottom-founded structure simulation, a test pile was designed so that its stiffness, natural frequencies and modes and damping could be varied. The ice movement against the pile was arranged to have constant acceleration in order to excite different modes with differing ice velocities. The flexibility of the drive system caused jerky ice movements with low velocities.Analysis of the recorded ice forces and acceleration include the refinement at measured ice forces by eliminating the response of the measuring system itself using the dynamic equilibrium or transfer function approach. The frequencies and the damping of vibrations were analysed using a Fourier signal analyser.Scaling laws are discussed and it is noted that full similitude cannot be achieved for both ice interaction force and pile and ice vibrations.Results so far show similarity with in-field ice force histograms: both random and saw-tooth like repetitious ice force fluctuations appear. The change from one interaction mode to the other occurs with increasing drive velocities. With high velocities relatively smooth random ice crushing occurs and in some cases natural modes are stable. The greatest energy content of the ice force does not always coincide with the natural frequencies of the structures.     

光纤光栅传感器在冰力测量中的应用

目前,现场直接测量冰力的方法大多是采用压力盒或测力计。基于光纤光栅传感器的许多优点,根据等强度梁工作原理,自行研制了一种光纤光栅冰力传感器并对灵敏度系数进行了标定。将它应用于室内开展的冰力模型试验,测得的冰力在数值大小和特性上均与实际比较符合。说明设计方案和思想是正确的,同时与传统的测力计相比,具有制作方便、体积小质量轻以及费用较低等优势;若能进行更科学的封装后,将会在实际工程中发挥积极作用。     

Probabilistic force calculations for structures in ice-covered seas

Ice ridges are expected to govern the design of conical structures in the arctic offshore against sliding forces and to affect the design of gravity or pile structures against overturning moments. Given that the mechanics of sea ice and the degree of consolidation and failure mode of ice ridges against a particular structure geometry are specified, there will still be uncertainty as to the size, shape and number of ridges that may impact a structure placed in these areas. The situation is analogous to designing against storm waves. The concern in both cases is with the probability of exceedance (risk) of rare events that approach the design strength of a surface-piercing structure founded on the seafloor.This paper describes a procedure for calculating the probability distribution of ice forces on a structure. A Monte Carlo approach is taken, together with ice mechanics, to convert information on structure geometry, structure location, and ice conditions at the location into a probability distribution for the force that will be imposed on the structure over a specified time period. The probability calculation is comprehensive in the sense that it can accommodate information on ice movement, ridge spacing, ridge geometry, etc. A comprehensive calculation gives the best estimate of risk under the assumptions made, and provides a framework for making prompt use of additional data as it is gathered. The data gathering effort itself can be focused by determining those environmental parameters to which the design ice force is most sensitive at acceptable risk levels.     

动冰力模型参数对墩柱结构非线性地震反应影响研究

结冰水域墩柱结构往往被大片的海冰包围,地震作用下,把冰与墩柱结构的相互作用以动冰力模型的形式考虑将大大简化结构地震反应的工作量,但合理的动冰力模型参数仍有待于进一步研究。本文对已有冰力模型进行分析,在适用于地震动力反应分析的Croteau冰力模型的基础上,建立冰水域墩柱结构地震反应计算模型,并以一桥墩为研究对象,研究该冰力模型参数对墩柱结构地震非线性反应的影响。结果表明:地震作用下海冰对桥墩的影响随着冰力模型中加载位移的增大而减小,且加载位移对墩底的剪力影响较小而对弯矩影响较大;动冰力模型中的位移比小于1.5时,结构的地震响应偏小,为了冰水域墩柱结构的抗震设计更安全,建议动冰力模型中位移比取2.0～2.5。     

Effect of temperature on the strength and viscosity of ice

Coustitutive equations, which describe viscoplastic deformation of ice under a complex stress state, were developed based upon experimental and theoretical investigations. The equations take into account the temperature effect on the strength and viscosity of ice under high pressures. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 2, pp. 9–13, March–April, 1996.     

Practice and theory of use of recoiling artillery cannons for the embedment of structural components

A rig for shooting anchors and piles into the ground, and the range its practical application are described. Fundamentals of the theory of the impulsive impression of structural components are presented. A method is proposed for approximate determination of the force exerted by the soil in resisting the movement of structural components embedded from artillery cannons.Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 5, pp. 9–12, September–October, 2004.     

线性结构物理参数识别

本文研究了单自由度结构体系的物理参数识别方法,给出了在质量已知时对结构刚度、阻尼进行识别的计算公式.本文同时还在线性结构动力反应分析解析递推格式的基础上,研究了作用有一个外力的线性多自由度结构体系(如海洋平台导管架冬季经常受到海冰荷载冲击)的结构物理参数识别方法,给出了同时识别结构质量、刚度及阻尼矩阵的计算公式.本文所提出方法没有引入任何假定,且公式物理意义明确.文末给出了一个算例.     

土体冻胀敏感性评价

 假定冻胀是由冻土内冰透镜体的生长引起的;冰透镜体的生长由热力学Clapeyron方程控制,并且依赖于已冻结区与未冻结区之间冻结缘是否存在。未冻水和冰共存于冻结缘的孔隙中;冰水交界面处的吸力使水产生流动,并为冰透镜体的生长补给水分。同时,通过定义1个新的简单的“有效应力”的概念,来判断是否会萌生新的冰透镜体,并提出1个简单的冻胀模型。该模型仅通过几个简单的土的参数,就可以计算土体冻胀量及冻结深度。在此基础上,利用所建立的模型对不同土的冻胀敏感性进行分析。土的冻胀敏感性必须结合环境条件来评估,如上覆压力、温度梯度、降温速率及地下水位埋深等;而某些土在传统的分类中属于弱冻胀土,但在一定环境条件下,仍会产生显著的冻胀量或冻胀压力。