Application of high-pressure water jet technology and the theory of rock burst control in roadway

This paper puts forward using high-pressure water jet technology to control rock burst in roadway, and analyzes the theory of controlling rock burst in roadway by the weak structure zone model. The weak structure zone is formed by using high-pressure water jet to cut the coal wall in a continuous and rotational way. In order to study the influence law of weak structure zone in surrounding rock, this paper numerically analyzed the influence law of weak structure zone, and the disturbance law of coal wall and floor under dynamic and static combined load. The results show that when the distance between high-pressure water jet drillings is 3 m and the diameter of drilling is 300 mm, continuous stress superposition zone can be formed. The weak structure zone can transfer and reduce the concentrated static load in surrounding rock, and then form distressed zone. The longer the high-pressure water jet drilling is, the larger the distressed zone is. The stress change and displacement change of non-distressed zone in coal wall and floor are significantly greater than that of distressed zone under dynamic and static combined load. And it shows that the distressed zone can effectively control rock burst in roadway under dynamic and static combined load. High-pressure water jet technology was applied in the haulage gate of 250203 working face in Yanbei Coal Mine, and had gained good effect. The study conclusions provide theoretical foundation and a new guidance for controlling rock burst in roadway.

Assessing the influence of jet-grouting underpinning on the nearby buildings

This paper focuses on the underpinning-induced ground movement due to jet-grouting.Jet-grouting technique can cause distortions as a result of an inaccurate processing sequence and/or errors made at different stages of work execution.The aim of this paper is to determine the minimum value of such movement on the basis of the findings obtained at two similar construction sites located in the Historical Center of Moscow,considering that the maximum value is usually unpredictable.Numerical simulation of the process of soil eroding agrees well with the observational data at the current stage.It was found that the minimum value of deformations(only settlement was considered in this study) due to jetgrouting is no less than 2-3 mm.By contrast,the negative scenario of deformation due to foundation underpinning is clearly demonstrated.Also,this paper provides some general solutions for excavation supporting system as well as for underpinning design.

Theory,technology and application of grouted bolting in soft rock roadways of deep coal mines

The grouted bolt,combining rock bolting with grouting techniques,provides an effective solution for controlling the surrounding rock in deep soft rock and fractured roadways.It has been extensively applied in numerous deep mining areas characterized by soft rock roadways,where it has demonstrated remarkable control results.This article systematically explores the evolution of grouted bolting,covering its theoretical foundations,design methods,materials,construction processes,monitoring measures,and methods for assessing its effectiveness.The overview encompassed several key elements,delving into anchoring theory and grouting reinforcement theory.The new principle of high pretensioned high-pressure splitting grouted bolting collaborative active control is introduced.A fresh method for dynamic information design is also highlighted.The discussion touches on both conventional grouting rock bolts and cable bolts,as well as innovative grouted rock bolts and cables characterized by their high pretension,strength,and sealing hole pressure.An examination of the merits and demerits of standard inorganic and organic grouting materials versus the new inorganic–organic composite materials,including their specific application conditions,was conducted.Additionally,the article presents various methods and instruments to assess the support effect of grouting rock bolts,cable bolts,and grouting reinforcement.Furthermore,it provides a foundation for understanding the factors influencing decisions on grouted bolting timing,the sequence of grouting,the pressure applied,the volume of grout used,and the strategic arrangement of grouted rock bolts and cable bolts.The application of the high pretensioned high-pressure splitting grouted bolting collaborative control technology in a typical kilometer-deep soft rock mine in China—the soft coal seam and soft rock roadway in the Kouzidong coal mine,Huainan coal mining area,was introduced.Finally,the existing problems in grouted bolting control technology for deep soft rock roadways are analyzed,and the future development trend of grouted bolting control technology is anticipated.

房屋建筑施工技术中地基处理技术探讨

随着我国城市化进程不断深入,房屋建筑规模不断扩大,对地基的要求也日益提高。地基作为承担整个建筑荷载的基础,其质量和强度直接影响着建筑的安全性能和使用寿命。目前,房屋建筑工程中常见的地基处理技术主要有深基桩技术、添加黏结剂以及对边坡和排水设施的处理三大类。深基桩技术通过在地基下深挖桩洞,并在其中铺设和浇筑混凝土桩,利用桩身和土体间的粘着力,有效将建筑荷载传导到更深的地层,大大提高了地基的强度和稳定性。此外,在填土或周边土体中添加水泥或石灰等黏结剂,也能够增强土体的结合力和抗剪性能。同时,对建筑边坡进行混凝土或钢支撑的加固处理,以及做好周围地下水的控制排水,都能有效防止地基因滑坡或浸润而强度下降的情况发生。

Prevention and treatment technologies of railway tunnel water inrush and mud gushing in China

Water inrush and mud gushing are one of the biggest hazards in tunnel construction. Unfavorable geological sections can be observed in almost all railway tunnels under construction or to be constructed, and vary in extent. Furthermore, due to the different heights of mountains and the lengths of tunnels, the locations of the unfavorable geological sections cannot be fully determined before construction, which increases the risk of water inrush and mud gushing. Based on numerous cases of water inrush and mud gushing in railway tunnels, the paper tries to classify water inrush and mud gushing in railway tunnels in view of the conditions of the surrounding rocks and meteorological factors associated with tunnel excavation. In addition, the causes of water inrush and mud gushing in combination of macroand micromechanisms are summarized, and site-specifc treatment method is put forward. The treatment methods include choosing a method of advance geological forecast according to risk degrees of different sections in the tunnel, determining the items of predictions, and choosing the appropriate methods, i.e. draining-oriented method, blocking-oriented method or draining-and-blocking method. The treatment technologies of railway water inrush and mud gushing are also summarized, including energy relief and pressure relief technology, advance grouting technology, and advance jet grouting technology associated with their key technical features and applicable conditions. The results in terms of treatment methods can provide reference to the prevention and treatment of tunnel water inrush and mud gushing.

Discussion on Anti-Seepage Technologies in the Construction of Small-Scale Rural Water Conservancy Projects

In order to ensure the sustainable growth of rural economy,it is necessary to carry out further research on small-scale water conservancy projects and solve the seepage issue in rural areas.Based on the application significance of small-scale rural water conservancy projects and the analysis of anti-seepage technologies,along with specific examples,this paper specifically discusses the application of high-pressure jet technology,so as to provide reference for the development of engineering construction.

海上旋喷桩施工移动作业平台研究应用

为解决浅滩海域、低净空以及既有桥梁结构对旋喷桩施工的影响,结合深中通道东人工岛工程,对海上移动作业平台+接杆旋喷桩施工技术展开研究并投入生产应用。工程实践表明:1)移动作业平台+接杆旋喷桩施工技术有效地解决了海上旋喷桩施工存在的技术难题,作业平台的适用性广泛;2)基于理论计算公式的提速动态调控手段可较好地保证旋喷桩施工质量,水泥用量的偏差率仅为2.4%;3)施工过程对既有桥梁结构的影响主要表现为顺桥向的水平位移,变形值在-1.3~1.7 mm范围波动,满足极敏感建(构)筑物的高控变要求。

水利水电工程中高压喷射灌浆技术

在我国工程建设工作进行的过程中,水利工程建设是一项重要的工作,它不仅可使我国的农业生产得到更好的发展,同时也具备抗洪、蓄水等作用,因此,我国的水利工程施工正在受到越来越多的关注和重视。以某项目为例,对水利水电工程施工中的高压喷射注浆技术进行了较为详细的阐述和分析。

高压旋喷后注浆技术提高单桩承载力应用研究

文中结合项目实例,阐述了高压旋喷后注浆技术提升桩体承载力的机理,分析了高压旋喷后注浆的方式,探究了注浆量、注浆压力、注浆管安装、开塞等施工中的技术要点,挑选三根试验桩,运用自平衡静载试验法对试验桩进行了单桩竖向承载力试验。结果表明,三根桩的单桩竖向抗压极限承载力均高于设计要求,高压旋喷后注浆技术对桩体承载力的提升有显著作用。

三管与双管高压旋喷注浆截水技术的对比应用

某三面临江、具有地下水丰富且存在承压性等复杂特殊水文地质条件的深大基坑截水帷幕工程,前期施工采用常规的三管高压旋喷注浆技术,截水失效。后期经过一系列的勘探试验、原因分析及论证后,改用双管高压旋喷注浆(外掺水玻璃)的施工技术对已施工的截水帷幕进行加固。加固后截水帷幕达到设计截水要求,截水效果得到显著提升。对两种高压旋喷桩注浆截水技术进行对比研究,结果表明双管高压旋喷注浆(外掺水玻璃)的施工技术对于类似该项目地下水量丰富具有承压性,且可能存在动态水流等复杂特殊的水文地质条件具有更强的适应性。

深中通道深厚砂层高压旋喷桩止水帷幕施工工艺研究及应用

深中通道西人工岛采用插入式钢圆筒及弧形钢板副格围闭的方案快速形成岛体结构。岛内陆域形成采用深井降水联合回填砂大超载比堆载预压进行岛内软基处理。地基处理后,在岛内进行明挖现浇隧道施工。由于人工岛所在海域钢圆筒底部多为粗砂、砾砂、砂砾状强风化岩、碎块状强风化岩,与海水联通,具有较高的渗透性。为满足西人工岛基坑内的渗流稳定和突涌稳定要求,达到止水的效果,采用在钢圆筒及副格内侧设置3排高压旋喷桩止水帷幕阻断钢圆筒围护结构岛内外的渗流路径。对外海深厚回填砂层高压旋喷止水帷幕施工工艺进行系统研究,通过工艺试验论证,确定最优施工参数并优化调整施工工艺,为类似工程提供经验借鉴。

高压旋喷桩处理淤泥地基施工工艺研究

文海水库坝基深厚软土层厚度大于97m,局部区域存在分布位置及厚度不一的淤泥质土夹层,现场施工极为困难。本文针对施工中旋喷桩水泥加固土不凝固、不成桩等难题,系统探讨和分析了不成桩的原因,通过方案比较和现场试验,结合技术参数调整和优选外加剂,形成了适合深厚软基处理的高压旋喷桩施工方案和深厚软基施工工艺,相关技术可为类似工程提供参考。

水利水电工程防渗施工技术探讨

随着水利水电工程项目建设速度的不断加快,防渗问题和相关的施工技术成为该领域的研究重点。文章针对水利水电工程项目中渗漏问题的影响因素以及防渗施工技术的应用现状进行了讨论,总结了灌浆防渗技术、射水防渗墙技术和碾压混凝土抗渗透技术的特点及应用条件,并结合应用灌浆防渗技术的实际案例,分析了实际项目工程的防渗处理效果。通过对项目防渗技术应用的研究可知,需要结合项目的实际地质条件和参数选择防渗技术,采用合理的防渗技术能够有效解决项目的渗透问题,可以进一步提升项目的施工质量,保障工程的安全性。

高喷桩与钢管桩对既有桥梁基础联合防护施工技术研究

基于乐山市金口河区金龙大渡河大桥中墩基础防护工程实例,对高喷桩、钢管桩的施工特点、施工技术以及质量检查方法等进行了分析与总结。实践证明:高喷桩和钢管桩联合应用能够弥补各自的不足,取长补短,进而获得预期效果。所取得的经验可为类似工程施工提供参考。

海堤加高加固施工技术研究

针对水利工程项目海堤加高加固施工技术展开研究。结合堤坝所在水域环境的水位信息,对混凝土防渗墙的高度以及原堤坝表层的切割深度进行设计,将其作为施工的基准。借助测量网测量了堤坝当前阶段的不透水临界位置,将其作为堤坝坡角开挖的目标深度,按照错位的方式对铺膜处理后,利用高压喷射灌浆防渗施工技术,基于堤坝坡角对地基裂缝以及混凝土防渗墙进行施工。实际应用结果表明,应用设计的海堤加高加固施工技术后,坝顶、坝身以及堤坝基底的渗流量分别稳定在1.20×10^(-9)、8.00×10^(-9)和2.30×10^(-9)cm/s以内,均达到了水利工程项目施工标准。

高压喷射灌浆技术在堤防渗漏抢险中的应用

在堤防渗漏险情中,高压喷射灌浆主要用于处置初发险情或用于病险堤段的除险加固,根据不同的地质情况,可考虑采用不同组合形式的高压喷射灌浆,即:(1)双管高压旋喷法;(2)双管高压摆喷直线搭接法;(3)双管高压摆喷折线搭接法等。经过实践证明,相对于其他软基防渗措施,高压喷射灌浆在适用性方面具有很大优势。

王河地下坝高喷灌浆与振动沉模试验研究

为了研究高压喷射灌浆防渗技术和振动沉模防渗板墙技术在工程中综合运用的可能性和合理性,结合莱州王河地下坝建设进行了现场试验。在对高压喷射灌浆单孔和浅层连续墙、振动沉模板墙、高喷和沉模组合墙、组合围井试验的基础上,提出了适合地下坝建设的工艺参数。通过开挖检查、抽水试验、室内实验,证明防渗体各项检测指标达到了设计要求,工效及经济分析证明两者的结合比单一的高喷工艺工效高54.8%、造价低15%。

风积砂地层隧道导向水平旋喷桩超前加固与预留核心土台阶法施工技术

为解决风积砂地层隧道施工难题,提出了风积砂地层隧道施工的导向水平旋喷桩超前支护技术和先行施作仰拱边墙结合部预留核心土台阶法开挖技术,前者的技术关键是导向技术,后者的技术关键是上下台阶施工长度、上下核心土临时加固质量以及两侧墙角仰拱结合部快速跟进时机。通过现场工艺试验、数值模拟以及工程施工实践表明:采用水平旋喷桩超前支护与预留核心土台阶法联合施工,能有效控制风积砂地层的变形,确保施工安全和施工进度。

高压旋喷桩在砂卵砾石层的质量问题及控制措施

高压旋喷桩具有施工速度快、成本较低等特点,在防渗和地基加固过程中得到广泛应用。然而规范对于不同地质条件下高压旋喷桩施工工艺及参数取值范围差异较大,工程实践表明高压旋喷桩在砂卵砾石层中施工质量不易控制。以某航道枢纽工程围堰高压旋喷桩施工为例,通过对施工过程中地质条件、施工工艺、检测结果的系统分析,指出了高压旋喷桩施工质量问题及其产生原因,并提出了相应的改进措施。通过采用设备改进、分序施工、调整提升速率、增加水泥用量等措施,高压旋喷桩在砂卵砾石层中的施工质量得到了有效改善。

水平旋喷桩技术经济分析

水平旋喷桩作为一种新型岩土加固技术,在浅埋、软弱、松散、富水地层中具有很好的支护、防水等优势,通过在施工中的成功应用,已得到地下工程界的广泛认同。但水平旋喷桩作为一种较新的施工工艺,目前尚无成熟的配套定额。结合其在深港隧道中施工方案,从施工组织的角度分析工料机消耗,对水平旋喷桩进行单价分析。