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.

Application of Anti-seepage Technology in the Construction of Hydraulic Engineering Projects

With the development of China's economy,the implementation scale and scope of hydraulic engineering projects are increasing,and the application of anti-seepage technology has an important influence on the construction quality of hydraulic engineering.In this paper,the significance and problems of the application of anti-seepage technology in the construction of hydraulic engineering projects were mainly analyzed,and specific application strategies were proposed.

Analysis of Grouting Technology in Building Construction

The application of grouting technology in housing construction is to inject liquid grout into the cavities and cracks of housing construction.After it solidifies,the stability of housing construction can be improved.Grouting technology is not only very convenient but is also environmental-friendly,and it is relatively low-cost.Therefore,it is widely used in housing construction.In this paper,the types of grouting technology and its application advantages in housing construction are analyzed,and specific application strategies are put forward,in hopes of improving the quality of housing construction.

Failure mechanism of bolting support and high-strength bolt-grouting technology for deep and soft surrounding rock with high stress

In deep underground mining, the surrounding rocks are very soft with high stress. Their deformation and destruction are serious, and frequent failures occur on the bolt support. The failure mechanism of bolt support is proposed to solve these problems. A calculation theory is established on the bond strength of the interface between the anchoring agent and surrounding rocks. An analysis is made on the influence law of different mechanical parameters of surrounding rocks on the interfacial bond strength. Based on the research, a new high-strength bolt-grouting technology is developed and applied on site. Besides, some helpful engineering suggestions and measures are proposed. The research shows that the serious deformation and failure, and the lower bond strength are the major factors causing frequent failures of bolt support. So, the bolt could not give full play to its supporting potential. It is also shown that as the integrity, strength, interface dilatancy and stress of surrounding rocks are improved, the bond strength will increase. So, the anchoring force on surrounding rocks can be effectively improved by employing an anchoring agent with high sand content, mechanical anchoring means, or grouting reinforcement. The new technology has advantages in a high strength, imposing pre-tightening force, and giving full play to the bolt supporting potential. Hence, it can improve the control effect on surrounding rocks. All these could be helpful references for the design of bolt support in deep underground mines.

Discussion on Anti-seepage Wall and Anti-seepage Technology of Water Conservancy Project

The water infiltration problem of water conservancy projects is one of the more common problems in the construction of water conservancy projects,which seriously affects the overall construction quality and safety of water conservancy projects.This article studies the causes of water infiltration in water conservancy projects and introduces related antiseepage technologies,hoping to be a reference for the implementation of anti-seepage projects.Through research,it is found that the factors that cause water infiltration in water conservancy projects include water conservancy project structural changes,environmental factors and construction factors.Relevant personnel can use concrete anti-seepage wall construction technology and high-pressure jet grouting technology to do the relevant anti-seepage work of water conservancy projects.

Utilizing a novel fiber optic technology to capture the axial responses of fully grouted rock bolts

Rock bolts are one of the primary support systems utilized in underground excavations within the civil and mining engineering industries. Rock bolts support the weakened rock mass adjacent to the opening of an excavation by fastening to the more stable, undisturbed formations further from the excavation. The overall response of such a support element has been determined under varying loading conditions in the laboratory and in situ experiments in the past four decades; however, due to the limitations with conventional monitoring methods of capturing strain, there still exists a gap in knowledge associated with an understanding of the geomechanical responses of rock bolts at the microscale. In this paper, we try to address this current gap in scientific knowledge by utilizing a newly developed distributed optical strain sensing(DOS) technology that provides an exceptional spatial resolution of 0.65 mm to capture the strain along the rock bolt. This DOS technology utilizes Rayleigh optical frequency domain reflectometry(ROFDR) which provides unprecedented insight into various mechanisms associated with axially loaded rebar specimens of different embedment lengths, grouting materials, borehole annulus conditions, and borehole diameters. The embedment length of the specimens was found to be the factor that significantly affected the loading of the rebar. The critical embedment length for the fully grouted rock bolts(FGRBs) was systematically determined to be430 mm. The results herein highlight the effects of the variation of these individual parameters on the geomechanical responses FGRBs.

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.

Mechanical Behaviors and Deformation Properties of Retaining Wall Formed by Grouting Mould-Bag Pile

The simplified mechanical model and finite element model are established on the basis of the measured results and analysis of the grouting pile deformation monitoring,surface horizontal displacement and vertical displacement monitoring,deep horizontal displacement(inclinometer)monitoring,soil pressure monitoring and seepage pressure monitoring in the lower reaches of Wuan River regulation project in Shishi,Fujian Province.The mechanical behavior and deformation performance of mould-bag pile retaining wall formed after controlled cement grouting in the silty stratum of the test section are analyzed and compared.The results show that the use of controlled cement grouting mould-bag pile technology is to strengthen the soft stratum for sealing water and reinforcement,so that it can rock into a retaining wall,which can both retain soil and seal water with excellent effect.The control of cement grouting technology not only makes the soft soil rock in the range of retaining wall of mould-bag pile,but also makes a wide range of soil around the mould-bag pile squeeze and embed to compaction;and its cohesion and internal friction angle increased,so as to achieve the purpose of reducing soil pressure and improving mechanical and deformation properties of retaining wall.

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.

暗挖地铁车站施工中靶向注浆技术的影响因素及效果控制

[目的]常规注浆施工技术中浆液无效扩散较为严重,对岩土体的加固效果不理想。对此,需研究靶向注浆技术在地铁车站及隧道预注浆施工中的应用。[方法]阐述了靶向注浆技术的加固机理,基于双液浆的流变方程,并结合均匀毛管组理论,分析靶向注浆技术的影响因素,推导得到双液浆柱形渗透扩散时扩散半径及浆液压力计算式。将推导得到的理论计算式应用于某地铁车站的预注浆工程施工中,以验证预注浆施工的效果。[结果及结论]靶向注浆技术将压密注浆技术和渗透注浆技术相结合,在保证注浆效果的同时能节约材料的用量并保护周边环境。参数分析显示:浆液扩散半径值受地下水压、浆液流速、双液浆黏性参数A和黏性参数B的显著影响,在所假定的参数变化范围内,浆液扩散半径的变化规律得到了较好的体现。现场监测数据表明,整个预注浆施工过程中未造成地表抬升和环境污染,注浆加固效果可达到安全开挖要求,达到了预期的效果。

区域治理注浆材料优选技术研究

区域治理是防治煤矿底板水害的有效手段。本文针对云驾岭矿19101工作面治理过程中大注浆量问题,以不同注浆材料配比制浆、取样、化验,通过浆液结石体与泥岩抗压强度值比对、隔水层阻水系数2个方法确定,水泥与粉煤灰3∶7的配比是可以满足底板水防治要求的。同时,将试验结果推广应用,并跟踪、监测井下钻探、物探以及回采涌水结果均表明治理效果显著。注浆材料优选技术可以为注浆量大的工程项目提供有益借鉴,助力煤矿企业降本增效,提升发展质量。

托顶煤巷道易片冒顶板变形机理与超前导管预注浆控制技术研究

目的 为探究厚煤层易片冒区域托顶煤巷道顶板变形破坏机理,并对易片冒区托顶煤巷道顶板进行有效控制,方法 以常村煤矿2701工作面皮带运输巷为例,通过等截面梁理论分析托顶煤巷道顶板破断成因,研究托顶煤巷道顶板的稳定性与巷道宽度和顶煤强度的关系。通过极限平衡准则得到巷帮位移的计算公式,证明托顶煤巷道具有帮顶协同变形机制。建立托顶煤巷道数值模型,研究巷道埋深、侧压系数、顶煤厚度和顶煤强度与托顶煤巷道围岩稳定性的关系。结果 结果表明:巷道埋深越大,其对托顶煤巷道两帮稳定性的影响越大;侧压系数的增加对巷道两帮和底鼓量的影响更大,对顶板影响较小;顶板下沉量与顶煤厚度呈正相关,底鼓量则与顶煤厚度呈负相关;顶煤强度的增加使巷道顶板下沉量与两帮移近量均近似呈线性减小趋势,底鼓量基本保持不变。结论 通过幂律型流体柱形渗透注浆扩散理论得到超前导管注浆半径,由此提出托顶煤巷道超前导管预注浆帮顶联合控制技术,成功控制易片冒托顶煤巷道顶板冒落问题,可为类似地质条件的托顶煤巷道顶板控制提供借鉴。

公路路基工程智能建养关键技术研究与展望

路基是公路的主要承重结构。随着我国公路建设由高速发展转向高质量发展,数字化施工技术、智能化建设以及信息化管控成为路基工程中的核心技术手段。本文综述了路基工程智能建养关键技术的研究现状,并主要从建筑信息模型(building information modeling,BIM)技术、路基智能压实技术、路基健康监测与评价技术以及路基智能注浆加固技术4个方面进行分析。目前存在问题如下:BIM技术在路基工程领域中的应用还处于起步阶段,缺少合理的施工质量量化指标以及成本估算方法;智能压实技术理论研究薄弱,质量均匀性评价研究较少;现有路基监测与评价技术的测量方法易受到其他因素影响,人工干预较大;注浆加固技术没有统一的质量评价指标,大多还是凭借工程经验和理论分析来评价。因此,未来需要针对提出的问题对各项关键技术开展智能化理论与应用研究,为路基工程智能化建养提供指引。

不规则采空区下特厚煤层综放面注浆扩散规律及加固技术

为了解决不规则采空区下特厚煤层综放强采动过程中矿压与围岩控制难题,以山西宁武榆树坡煤矿5106综放面为工程背景,通过现场监测的手段研究了不规则采空区下特厚煤层综放面矿压显现特征,并在此基础上采用数值模拟的方法分析了不同裂隙特征参数的浆液羽状扩散规律,揭示了三角锯齿形动态循环脉冲注浆增注机理,形成了三角锯齿形动态循环脉冲注浆加固技术,制定了围岩注浆加固技术实施方案,并进行了工程应用。研究结果表明:回采期间工作面支架阻力整体呈现出“两端小、中间大”的趋势,不同推进距离工作面方向支架工作阻力分布特征存在明显差异;注浆扩散形状受裂隙分布的影响,随裂隙数量的增加,注浆扩散形状从初始的圆形转变为裂隙引导的不规则羽状;实施脉冲注浆加固技术后,实测发现脉冲注浆扩散速率提升了约25%,综放面煤体裂隙被充分充填,围岩加固效果显著,实施效果良好。

韧性视角下华北型煤田底板承压灰岩水原位保护技术研究

目的为推进保水开采技术高质量发展,有效解决华北型煤田底板承压灰岩水原位保护问题,方法根据扰动下系统韧性演化特征,从韧性抵抗力、恢复力和适应力出发,分析煤层底板在采动和承压水影响下由抵抗到恢复及再适应的全过程。基于“精准、高效、全面”的核心内涵,构建以“治理靶区精准确定、多分支井高效注浆、保水效果全面评价”为主体的华北型煤田底板承压灰岩水原位保护技术框架。结果结果表明:治理靶区精准确定包括垂向层位确定和横向靶位确定;多分支井高效注浆包括定、钻、注3个步骤;保水效果全面评价包括底板岩层注浆效果评价和水资源承载力恢复评价。根据底板破坏深度和临界隔水层厚度计算,确定底板注浆垂向层位,根据关键指标参数探测和脆弱性指数模型计算确定底板注浆横向靶位,形成底板注浆靶区的量化确定方法并开发相应的软件系统。多分支井注浆结合随钻定向技术,对相关裂隙等进行注浆封堵,减少直井段数量,提高钻井效率。针对保水开采中“安全开采”和“水资源保护”理念,提出基于底板岩层注浆效果探测和水资源承载力恢复监测的原位保水效果评价方法。结论在安徽某矿进行工程应用,保障底板承压灰岩水上开采煤层安全性的同时,兼顾矿区经济效益与生态环境发展。研究结果完善了承压水上保水开采技术体系,为后续研究及现场应用提供借鉴。

煤矿井下定点注浆工艺研究及装备研究应用

针对定向钻孔施工遇破碎地层成孔深度浅、破碎带塌孔、定向钻进困难等问题,提出了采用定点注浆钻具组合施工破碎地层定点注浆加固的技术方案,介绍了其技术原理,开发了定点注浆位置优选工艺、封隔器坐封与解封工艺、注浆工艺等关键技术,研制开发了裸眼挤堵封隔器、高压密封注浆钻杆和高压送水器等关键钻具设备,形成了成套技术与装备,并在淮南进行了地面实验与现场试验,验证封隔器坐封、爆破和解封可调可控,在朱集东矿1151(3)轨顺6#钻孔中完成定点注浆加固,注浆加固后定向钻进顺利通过破碎带,为施工定向钻孔遇破碎地层提供了一种新的技术手段。

装配式建筑结构节点连接方式及施工技术改进研究

装配式建筑是一种具有节能、高效、可持续和可再配置特点的新型建筑结构,其节点连接技术对于确保建筑结构的稳定和安全至关重要。通过研讨改进装配式建筑结构节点连接技术,以提高装配式建筑的可靠性和经济性。首先对目前常用的装配式建筑节点连接技术和问题进行分析,其次,提出了一些改进的节点连接技术,并探讨采用新型连接件和新工艺来增强性能,其与传统连接技术进行比较分析,既提高了节点连接的稳固性和抗震能力,又增强了装配式建筑结构的整体性、节约成本,对于进一步探索装配式建筑的发展具有重要的理论和实践意义。

岩石隧道掘进机不良地质施工处置技术

岩石隧道掘进机(Tunnel Boring Machine,TBM)凭借其高效优质、作业安全等特点在铁路、公路、地铁、水利水电等领域广泛应用,在普通地质环境下推广顺利。复杂地质环境下致灾源多,如硬岩岩爆、软岩大变形、断层破碎带、涌水突泥等不良地质使TBM施工频繁出现围岩坍塌、支护失效、卡机淹井、设备损伤等问题。本文结合工程案例,从超前主动加固、注浆及锚固、管片支护、撑靴加固4个方面总结现有施工技术,以应对TBM穿越不良地质导致的刀盘卡机、护盾抱死、初期支护变形过大、撑靴打滑等问题,提升TBM在不良地质环境下的适应能力,为类似工程提供参考。

基于后注浆工艺纵横交错双向预应力装配式道路施工关键技术研究

为了提升我国公路工程装配化建造水平,基于后注浆法对预应力装配式道路设计与施工开展研究工作。从装配化道路结构创新设计、优化工艺流程、质量控制、提高结构耐久性、缩短建造工期、环境保护及推进行业转型发展等方面深化研究,建立了基于后注浆工艺纵横交错双向预应力装配式道路结构技术体系,采用了“纵横双向格构梁设计,双向交叉预应力,叠合板倒置支承工艺,后注浆法封孔”技术方案,整体遵循“模块化设计,分区段吊装,双向预应力张拉与封锚,后注浆施工”原则,技术方案经专家论证,可行有效,对推动我国公路工程装配化施工具有显著应用价值。

古兜山隧道富水段探测与处置技术研究

为探明古兜山隧道富水情况,通过超前钻孔、瞬变电磁法探测隧道富水段情况;针对古兜山隧道的富水情况,开展现场注浆止水加固试验研究,提出富水区注浆止水关键技术;综合考虑隧道地下水排放量与植被生态的平衡,给出隧址区的地下水允许排放量。研究结果表明:选择普通水泥-水玻璃双液浆用于钻孔揭露隧道涌水量较大的区域,确保注浆效果;综合考虑地下水压力、地层岩性、浆液的性质和浓度及注浆扩散半径等因素,确定注浆终压取值为5~6 MPa;针对植被、生态环保要求,按2年内恢复原始地下水位,确定泄洪口区、水库连接区及隧道近出口区的地下水允许排放量。