全风化花岗岩小净距隧道中夹岩柱注浆加固技术

根据天马山隧道工程实践,利用ABAQUS建立数值模型,从施工时力学的角度,对先行洞开挖后小净距隧道中夹岩柱加固前后的受力变形情况进行了数值模拟分析,计算结果表明:对中夹岩柱加固后,其力学性能增强,承载能力提高,在隧道开挖的过程中,靠近中夹岩柱一侧的初衬混凝土层拉应力区域明显减小。     

预应力张拉与孔道灌浆在屋架施工中的应用

结合工程实例，介绍了屋架预应力钢筋的张拉及孔道灌浆的过程控制，阐述了预应力钢筋张拉施工工艺，指出采用正确的施工工艺，使施工质量得到了保证。     

杂填石地基旋喷二次注浆成桩加固施工

通过对杂填石地基利用旋喷设备及二次注浆成桩施工方法的研究和应用，解决了在杂填石地层中难以成桩的技术难题，达到了提高地基承载力和减少不均匀沉降的效果。     

帷幕注浆控制建筑物沉降的数值模拟分析

以广州地铁小北站上部的既有建筑物及周围的地表沉降为研究目标,对采取地表深孔帷幕注浆加固措施这种工况,进行数值模拟研究,研究由于隧道的开挖、地下水流失所引起的既有建筑桩基沉降与地表沉降,分析加固措施止水效果的有效性,探讨和揭示地下水对地表及建筑物沉降方面的影响。结果表明,地表帷幕注浆提高了地层的参数,阻断了地下水的流动,减少了建筑物基底土层由于地下水流失,有效应力增大所引起的固结沉降,保证了建筑物在隧道施工期间的安全。     

高压旋喷注浆加固设计及应用

简述了高压旋喷的加固机理及计算模型，并结合设计实例介绍了其设计方案，归纳了高压旋喷注浆加固工序，实践证明高压旋喷注浆法经济、适应性强，对提高地基承载能力和限制不均匀沉陷有很好的控制作用。     

掺入豆石的灌浆料在加固工程中的应用

以豆石含量为变化参数,设计了5种灌浆料的配合比;通过试验方法,研究了灌浆料的施工性能（包括坍落扩展度（SF）、T500流动时间和L型仪试验）和抗压强度。试验结果表明,豆石含量增加,灌浆料T500流动时间变短,坍落度和扩展度（SF）变大,抗压强度降低。工程实例说明,掺入合适豆石的灌浆料能够满足工程应用的要求。     

静压注浆加固台背回填的研究和应用

结合工程实例,分析了静压注浆加固机理,详细介绍了静压注浆施工工艺及施工特点,并总结了静压注浆加固的相关注意事项,通过静压注浆对台背回填进行加固处理,从而达到提高地基承载力,减少路面沉降变形和桥头跳车的目的。     

灌浆及碳纤维补强技术在桥梁裂缝中的应用

结合具体工程实例,对钢筋混凝土连续箱梁工作中经常出现的受力裂缝的产生,提出了合理有效的处理方法。重点对裂缝灌缝封闭处理和碳纤维布粘贴的技术方法进行了详细的介绍,指出该技术能有效克服桥梁病害,延长桥梁的使用寿命,值得推广。     

隧洞施工洞内深孔注浆加固施工技术

以南干渠十二标工程施工为例,通过探讨洞内深孔注浆加固技术在隧洞工程下穿建筑群施工中的实施技术,提出相应的施工技术控制要点,旨在为同类隧道工程提供实例参考。     

非均质土层的注浆扩散特性与加固力学行为研究

注浆加固区域土层具有非均质性和原位变异性,土层参数服从一定的分布规律。基于随机分形理论和物性参数关联的特点,构建非均质土层的物性参数随机分布模型。基于Delaunay方法将土层分形网格结点连接成三角形网格,利用三角形面积坐标插值方法实现土层分形网格中动态参数向注浆有限元网格的传递。应用精细化的流固耦合力学模型,考虑土体物性参数动态变化和浆液时变效应的影响进行注浆扩散模拟,分析土层物性参数动态变化规律,研究非均质土层中浆液扩散范围和结石体的真实形态。通过定义不规则结石体的物理力学参数,研究荷载作用下注浆加固地层的应力和变形分布特征。     

湖南吉茶高速公路补育隧道注浆加固堵水施工技术

由福建建工集团承建的湖南吉首-茶洞高速公路C8标段补育隧道在右洞YK19＋850—860段、左洞ZK20＋110—120出现溶洞、长20多米的裂隙涌水带及多个较大股状涌水点并大量涌水,由于成功进行注浆堵水处理,达到止水和围岩固结双重效果,左右洞现已安全顺利贯通。本文以实例介绍补育隧道注浆堵水加固技术,通过对注浆工艺及注浆量进行计算分析,为隧道注浆堵水提供借鉴。     

高压旋喷桩在桥梁基础加固中的设计应用

为设计高压旋喷桩加固桥梁基础,分析了高压旋喷桩的成桩机理,结合工程特点,对旋喷桩直径、长度、数量、布置及相关参数进行设计,高压旋喷桩适用范围广,对周围地基的扰动小,成桩结构形式灵活多样,施工方便,造价较低,因此高压旋喷桩在现有桥梁基础加固中应用越来越广泛。     

某水库大坝除险加固帷幕灌浆工程施工工艺

针对某水库大坝由于蓄水压力逐渐增大,出现渗漏而危及大坝安全的严重问题,分析研究和采取了科学有效的帷幕灌浆工艺方法,对水库大坝进行了除险加固,有效地解决了大坝渗漏问题,确保了水库大坝的安全。     

机场复合道面基础二次注浆加固技术研究

针对上海某机场跑道改造中的基础注浆工程涉及到复合道面、二次注浆、不停航施工等诸多难点,从工程背景、施工难点、注浆参数、试验段设计、效果检测等各个方面进行全面阐述,形成了一套复杂条件下机场道面基础注浆加固技术,对我国机场类似工程有重要的指导意义。     

小导管注浆加固配合长管棚技术的应用

结合清源隧道松散坍方施工实例，介绍了小导管注浆加固配合长管棚施工技术的应用，分析了管棚、小导管和初期支护相互作用机理，表明了该施工技术是治理隧道坍方的有效手段。     

湘桂铁路框架涵施工控制与旋喷桩加固技术

结合湘桂铁路扩能改造工程柳南段Ⅰ标段框架涵的施工实例,从基底处理、模板系统、混凝土施工等几方面介绍了框架涵的施工工艺。针对该工程段地基不稳定的情况,采用旋喷桩进行加固,各项质量指标达到了设计要求。     

Experimental investigation on sealing efficiency of chemical grouting in rock fracture with flowing water

This paper presents an experimental investigation of the main factors that influence the sealing efficiency of chemical grouting in a permeated fracture replica. Chemical grouting has been widely used to control groundwater inrush in underground mining. However, the relationship between the sealing efficiency of grouting and its influencing factors is one of the many critical issues that still remain unsolved. The four factors tested in the orthogonal experiment include the fracture aperture width, initial water flow speed, gel time, and grout take. The sealing efficiency is evaluated and graded by the reduction of water drainage through the fracture after grouting. The experimental results of the orthogonal arrays show that two most influencing factors on sealing efficiency are the initial water flow speed and the aperture width, where the former has a higher impact than the latter. In a comparison with the two other factors, it is found that the grout take and gel time have less influence. The patterns of grout propagation are classified into four types: (1) total sealing off; (2) partial sealing off with erosion along boundaries; (3) partial sealing off with internal erosion; and (4) total erosion. The interaction between the injected grout and flowing water slows down the water flow and the grout starts to solidify at a downstream location where the retention time for grout is longer than its gel time.     

Numerical investigation of coal and gas outbursts in underground collieries

Coal and gas outbursts are a complex catastrophic unstable phenomenon that involve the ejection of large volumes of coal, and are often accompanied by gas, such as methane, carbon dioxide or a mixture of the two. Coal and gas outbursts are prevalent in deep and gassy mines where face advance rates are rapid, and where gas drainage is either poor or absent. The occurrence of progressively larger coal and gas outbursts, and the potential for the catastrophic collapse of coal pillars, is of increasing importance as mining is extended deeper in seams rich in methane and other hydrocarbons. A unique coupled gas flow and solid deformation numerical model, viz., RFPA^2D-GasFlow, has been developed and is applied to simulate the evolutionary process of such catastrophic coal failures in underground collieries. The finite element model, which incorporates the physics of gas flow in the coal seam, the physics of coal deformation and instantaneous failure, and the cross-couplings between them, is proposed. The model also incorporates small-scale variability in deformation modulus and strength of the coal and surrounding rock. The variability in modulus and strength is distributed via a fine-scale resolution model according to the Weibull distribution, where the distribution parameter determines the level of heterogeneity. This numerical model is applied to simulate the whole process of coal and gas outbursts, including stress concentration, coal fracturing, gas pressure-driven expansion, and outburst. The instantaneous outburst process and associated stress fields, gas pressure gradients and displacement vectors are presented step by step. The numerical simulations indicate that the instantaneous outburst is a complex phenomenon involving interactions between gas pressure, stress and the physico-mechanical properties of the coal, and it can occur under a variety of conditions. Successful numerical simulation of the whole coal and gas outburst process provides the basis for identifying the outburst mechanisms, parameterizing the causative processes, and to defining potential precursors of failure.     

土体劈裂注浆过程的数值模拟及浆脉形态影响因素分析

针对现有数值方法对土体劈裂注浆中裂缝产生和扩展过程模拟困难的现状,采用自主研发的基于有限元与流体体积函数的数值方法对劈裂注浆过程进行了模拟研究,再现了土体劈裂注浆过程中裂缝的产生以及浆脉扩展过程。数值模拟获得的劈裂注浆浆脉扩展过程与已有理论分析及试验所得规律基本一致,表明采用该方法模拟土体劈裂注浆问题是可行的。在此基础上分析了注浆深度和土体模量两个因素对浆脉形态的影响规律。结果表明:数值模拟可以呈现劈裂注浆过程的几个阶段,包含"浆泡"挤密、初始竖向劈裂、斜向二次劈裂等阶段;在二次劈裂发生之前的挤密阶段和竖向浆脉扩展阶段,地层竖向位移增加较小,而二次劈裂之后的斜向浆脉的产生和扩展是地层竖向位移增加的主要阶段;随着注浆深度的增加浆脉的分支越来越少而且方向性更加明显,浆脉宽度也越来越小;随着土体模量的增大,注浆孔周边"浆泡"体积减小,浆脉的宽度逐渐变窄。工程实例的模拟表明,该数值模型能很好的反映工程现象,对工程实践具有一定的指导意义。     

煤矿巷道涌水勘探与地面成孔注浆加固治理

针对某煤矿巷道二次出现涌水淹井事故,对矿区分别进行二维地震勘探和瞬变电磁法勘探,通过对勘探的结果进行综合分析,选定地面成孔注浆堵水的加固方案,最后介绍了地面注浆钻孔布设方案和注浆工艺,为类似工程提供了指导。