大直径加重管组合绳索取心钻具研究与应用

新型能源勘探与常规矿产资源勘探的要求有所不同,其主要特征是孔深、直径大、地层复杂、工程精度要求高,而小口径绳索取心钻进工艺技术已难以满足新型能源勘探的要求。为了解决这一问题,本次研究在小口径绳索取心钻具的基础上加以改进,研发了一种大直径加重管组合绳索取心钻具,并在浙江临安页岩气勘探区块钻探中应用,解决了大直径深孔取心效率问题,取得了良好的效果。该钻具具有孔底加压、工作稳定、保直防斜、冲洗液上返阻力小,一次性成孔等特点,对深孔大直径绳索取心钻探技术的探索研究具有一定的指导和启迪作用。本文重点介绍了该钻具设计思路和方案,钻具结构作用原理和主要技术参数及应用情况。     

厦门地下管线测量控制网的布设与实施

本文重点介绍了厦门地下管线测量控制网的设计及控制点的合理选取、外业观测和数据处理等问题。     

建(构)筑物下管桩长度检测方法

管桩中的铁磁性物质在地磁场中受到磁化而产生磁化强度,使管桩附近的磁场强度发生变化.把管桩中的铁磁性物质等效成直立磁性圆柱体,结合模型桩试验,研究了管桩外部的磁场特征,并且利用管桩外部的磁场特征确定了某居民小区住宅楼基础中管桩的长度.理论分析和工程应用均表明,磁测井法能够准确检测建(构)筑物下管桩的长度.     

倒虹吸混凝土管道的地震反应分析

基于土体的等效粘弹性模型,结合场地典型剖面的土体特性以及室内实验确定的各力学参数,采用时域积分和迭代的方法研究了沁河倒虹吸管道在地震作用下的反应,分析了管道截面中间底部点绝对地震位移、顶部点相对于底部点的地震动位移及管道动静综合主应力的变化规律;并根据有限元时程法的分析结果,按照混凝土承载能力极限状态设计式,对管身混凝土的抗拉、抗压安全度进行校核。结果表明,在人工地震波、调整后的E1 Centro和Pulgas地震波分别输入的情况下沁河渠道倒虹吸管道均满足抗震要求。     

X射线荧光分析仪用靶自动控制系统的设计

X射线荧光分析仪用靶自动控制系统主要由步进电机及其控制电路、光电检测电路、靶盘和齿轮传动五部分组成。该系统采用了单片机控制步进电机,从而驱动靶盘按要求转动相应的角度,并通过光电检测电路进行闭环控制,最终实现能量色散X射线荧光分析中靶的自动更换,解决了长期以来依靠人工更换靶的问题,提高了工作效率和安全性。该控制系统的靶中心点定位偏差不大于1 mm,并能满足能量色散X射线荧光测量工作中的测量要求。     

武汉地区预应力混凝土管桩模糊随机可靠性分析

通过考虑桩基失效具有随机性和模糊性,引入模糊数学的相关理论,将桩基沉降率作为模糊随机变量,对42组武汉地区预应力混凝土管桩试桩试验数据进行了模糊统计分析,确定了隶属函数,假定沉降率的概率分布,运用模糊事件的概率原理,得出了概率计算公式及可靠性指标计算方法,为工程实践中预应力管桩失效的评判提供参考。     

水泥搅拌桩挡土墙墙顶位移的修正算法

对水泥搅拌桩挡土墙的水平位移计算进行了探讨。以刚性桩法为基础理论和计算模型、弹性抗力法的计算结果为挠曲修正,首次提出一种既便于手算,又能考虑墙身挠曲变形的墙顶位移修正算法。     

顶管施工中注浆减摩作用机理的研究

长距离顶管施工中为减小顶进阻力通常采用注浆减摩措施。研究了注浆材料及其性能，对注浆过程中浆液与管道以及周围土体之间的相互作用机理进行了分析，探讨了浆液在土体中的渗流以及注浆对土层移动的影响，提出了注浆时应注意的几个问题。     

青藏铁路设计中热棒路基的应用及其技术指标

In accordance with the application of thermal pipe in the Qinghai-Tibet Railway subgrade project and the research data made on the Qingshuihe experimental field, this paper makes an attempt to illustrate the design principles, basis and technical characteristics, puts forward the problems needing further study, and pipe the reason and tendency of the longitudinal crack in the subgrade applied with thermal pipe.     

Underground geotechnical and geological investigations at Ekati Mine–Koala North: case study

Since 1998, BHP Billiton has mined diamonds at the Ekati Diamond Mine™ near Lac de Gras in the Northwest Territories of Canada. Current operations are based on mining multiple pipes by the open-pit method, but as some pits deepen, converting to underground mining is being considered.

As a test of underground mining methods and to provide access to the lower elevations of the Panda and Koala pipes, the Koala North pipe is being developed for underground mining. Initially, the top 40 m of the pipe were mined as an open pit to provide grade information and a prepared surface for the transition to underground mining. Currently, Koala North is being developed as an open-benching, mechanized, trackless operation. Although the method was successfully used at several De Beers diamond operations in South Africa, it has never been tested in an Arctic environment.

This case study describes basic geology, mining method layout and ongoing geological and geotechnical investigation. From the beginning of underground development, geotechnical daily routines have been fully integrated within the technical services department, which supports the operation. Geotechnical, geological and structural information obtained from underground mapping and core logging is compiled, processed, reviewed and analyzed on site by the geotechnical staff. Conclusions and recommendations are implemented as part of the operations in a timely manner. This ongoing “live” process enables the operators to make the most efficient use of resources both for ground support and excavations as well as to address safety issues, which are the top priority.