基于钻孔过程监测的花岗岩钻进比能研究

为了探究钻进参数与岩石质量之间的相关性关系,并寻求一个能够定量描述岩体质量的参数,利用安装了DPM系统的SGZ-IIIA型取芯钻机对一块1.25 m×2.00 m×1.00 m的花岗岩进行了6次钻孔试验,对每个孔设置不同的推进压强和转速等参数(压强分为400 kPa、600 kPa、800 kPa三挡,转速分为128 r/min、200 r/min两档),根据钻进位移与钻进时间计算得出钻进速度。结果表明,对于同一种岩石,如果在钻进过程中,转速、扭矩、推进压力等钻进参数不同,那么钻进速度也会相应变化,无法仅利用钻进速度来定量描述岩体质量,无法发挥DPM的优势。通过理论分析与花岗岩试验结果可知,钻进耗能为1.11~1.83 kJ/cm~3,平均值为1.523 kJ/cm~3,基于能量守恒定律,引入钻进比能的概念,发现此参数与岩石物理力学强度参数相关性高,可以用来表征岩石质量,从而实现通过岩石钻进快速确定岩体质量。     

TBM施工组织管理技术

TBM隧洞施工是以掘进作业为核心,以掘进、支护、出渣运输为主要作业,通风、供电、供水、排水等为辅助作业进行的。它具有并行性、协调性、连续性和密集性等特点,这决定了TBM施工组织管理技术上的特殊性。为此,在TBM施工组织管理方面主要采取以下技术措施:(1)根据TBM施工特点,建     

Design and development of hydrogen isotope sensor in liquid PbLi

Indian LLCB – TBM uses liquid Lead-Lithium (Pb-Li) as tritium breeder, neutron multiplier and coolant. Tritium bred in liquid PbLi stream has to be recovered by tritium extraction system. Therefore, a reliable sensor with quick response time for measurement of hydrogen isotope is essential.A hydrogen isotope sensor in liquid Pb-Li, based on permeation of hydrogen isotopes through metal (sensor material) is designed. The capsule shaped sensor, made of iron membrane coated with Pd from inside (downstream side), allow hydrogen isotope to permeate through it. The design work mainly includes the selection of proper material, its thickness and surface conditions, which is to be supported by numerical calculations for optimization of maximum permeation flux, fast response and fabricability. The numerical calculation utilizes a physical model having recombination of two hydrogen isotope atoms at the surface and atomic diffusion through the bulk. In this work, design calculations based on numerical simulation and fabrication procedure of the hydrogen isotope sensor are presented.     

Development of a potential based code for MHD analysis of LLCB TBM

A two dimensional solver is developed for MHD flows with low magnetic Reynolds’ number based on the electrostatic potential formulation for the Lorentz forces and current densities which will be used to calculate the MHD pressure drop inside the channels of liquid breeder based Test Blanket Modules (TBMs). The flow geometry is assumed to be rectangular and perpendicular to the flow direction, with flow and electrostatic potential variations along the flow direction neglected. A structured, non-uniform, collocated grid is used in the calculation, where the velocity (u), pressure (p) and electrostatic potential (?) are calculated at the cell centers, whereas the current densities are calculated at the cell faces. Special relaxation techniques are employed in calculating the electrostatic potential for ensuring the divergence-free condition for current density. The code is benchmarked over a square channel for various Hartmann numbers up to 25,000 with and without insulation coatings by (i) comparing the pressure drop with the approximate analytical results found in literature and (ii) comparing the pressure drop with the ones obtained in our previous calculations based on the induction formulation for the electromagnetic part. Finally the code is used to determine the MHD pressure drop in case of LLCB TBM. The code gives similar results as obtained by us in our previous calculations based on the induction formulation. However, the convergence is much faster in case of potential based code.     

二次衬砌、辅助洞室开挖与TBM掘进三同步施工技术

隧道掘进机（TBM）是长大隧道施工最先进的设备,以往只能待TBM掘进贯通后施作辅助洞室以及二次模筑混凝土衬砌,这与新奥法施工原理不相符合。结合南疆铁路吐库二线中天山隧道TBM施工实践,实现了二次模筑衬砌、辅助洞室开挖与TBM掘进三同步施工技术,有助于加强隧道施工与工程质量的安全、缩短施工工期,具有较高的推广价值。     

Disc cutter wear prediction for a hard rock TBM cutterhead based on energy analysis

Disc cutter wear is a crucial problem that influences the working efficiency and security of hard rock tunnel boring machines (TBMs). This wear results from friction energy accumulation and conversion. In this study, the process of hard rock TBM disc cutter wear is identified and analyzed by quantifying the collective energy change. This study starts with an analysis of the friction process between the disc cutter and hard rock. The relationship between the rolling force work and thrust force work of the disc cutter is examined. As a result, the disc cutter energy equation is determined, and the meaning of the upper and lower bounds of this equation are discussed. Based on the above results, the hard rock TBM cutterhead energy equation is then deduced. A method to identify the friction work is developed. According to the energy wear theory, the cutter wear law on hard rock for a TBM cutterhead is revealed, and a method for predicting disc cutter wear for a hard rock TBM cutterhead is advanced. Furthermore, the validity of this prediction method is confirmed by utilizing data from project cases.     

On the influence of face pressure, grouting pressure and TBM design in soft ground tunnelling

A three-dimensional finite element simulation model, which includes all relevant shield tunnelling components and allows for the modelling of the step-by-step construction process of the tunnel advance is used to analyse the influence of TBM operation parameters and design parameters for a shallow tunnel advance in homogeneous, soft, cohesive soil below the ground water table. The numerical sensitivity studies presented in this paper focus on the face support pressure, the grouting pressure, the trailer weight and the length, weight and taper of the shield machine. The simulation results are evaluated with respect to the settlements of the ground surface, the shield movement and the loading of the tunnel lining. The evaluation of the sensitivity analyses helps to obtain a more detailed insight into the influence of selected parameters relevant for the design and steering of TBM tunnel advances.     

引黄工程北干线#1隧洞施工方案探讨

山西省万家寨引黄一期工程北干线^#1隧洞洞长44.9km，最大埋深430m，全线70%的洞段处于地下水位以下，其施工方案直接影响着工程工期、投资及建成后的经济状况，通过对两台TBM、一台TBM施工方案及其施工工期、工程投资的比较，可以看出：一台TBM施工方案不仅工期短，如果严格执行招投标制度，工程投资可较两台TBM施工方案节省1.4亿元，同时部分使用钻爆法还可以对国内其他施工企业扩大再生产、提高竞争力有所帮助，该方案可降低造价，对将来的运营管理大有益处。     

TBM变速器油样铁谱诊断方法分析

对TBM变速器的油样铁谱数据．分别用三线值法和线性回归分析法进行处理，诊断实践证明，两者互为对照．配合磨粒图谱识别，具有很好的实用前景。     

硬岩掘进机主轴承外密封洞内修复技术

主轴承是TBM最为关键的部件,其寿命与状态直接影响TBM的寿命,一旦出现故障将严重影响掘进施工,甚至造成长时间停工,确保主轴承状态完好的关键措施之一就是其内外两套密封系统.通常情况下,主轴承洞内维修需要通过迂回导洞开挖扩大洞室,耗时很长、损失巨大.本文介绍了TBM施工过程中主轴承外密封系统出现的一次严重故障及其洞内修复方案、特别说明了刀盘在掌子面的固定方法.在故障诊断、因地制宜制定解决方案、实施以及预防措施等方面,可为大型施工设备的使用管理积累提供借鉴.