Double-face intelligent hole position planning method for precision blasting in roadways using a computer-controlled drill jumbo

To solve the uneven burden of same-type holes reducing the blasting efficiency due to the limitation of drilling equipment,we need a double-face program-controlled planning method for hole position parameters used on a computer-controlled drilling jumbo.The cross-section splits into even and uneven areas.It also considers the uneven burden at the hole’s entrance and bottom.In the uneven area,various qualifying factors are made to optimize the hole spacing and maximize the burden uniformity,combined with the features of the area edges and gridbased segmentation methods.The hole position coordinates and angles in the even area are derived using recursion and iteration algorithms.As a case,this method presents all holes in a 4.8 m wide and 3.6 m high cross-section.Compared with the design produced by the drawing method,our planning in the uneven area improved the standard deviation of the hole burden by 40%.The improved hole layout facilitates the evolution of precise,efficient,and intelligent blasting in underground mines.

Typical Underwater Tunnels in the Mainland of China and Related Tunneling Technologies

In the past decades, many underwater tunnels have been constructed in the mainland of China, and great progress has been made in related tunneling technologies. This paper presents the history and state of the art of underwater tunnels in the mainland of China in terms of shield-bored tunnels, drill-and-blast tunnels, and immersed tunnels. Typical underwater tunnels of these types in the mainland of China are described, along with innovative technologies regarding comprehensive geological prediction, grouting-based consolidation, the design and construction of large cross-sectional tunnels with shallow cover in weak strata, cutting tool replacement under limited drainage and reduced pressure conditions, the detection and treatment of boulders, the construction of underwater tunnels in areas with high seismic intensity, and the treatment of serious sedimentation in a foundation channel of immersed tunnels. Some suggestions are made regarding the three potential great strait-crossing tunnels-the Qiongzhou Strait-Crossing Tunnel, Bohai Strait-Crossing Tunnel, and Taiwan Strait-Crossing Tunnel--and issues related to these great strait-crossing tunnels that need further study are proposed.

Trend analysis and comparison of basic parameters for tunnel blast design models

One of the most important factors influencing on a tunnel blast efficiency is the proper design of blasting pattern. Among blasting parameters, blasthole diameter and tunnel face area are more significant so that any change in these parameters could finally affect on specific charge and specific drilling. There are mainly two groups of methods for tunnel blast design categorized based on the parallel cuts and angular cuts. In this research, a software for tunnel blast design was developed to analyze the effect and sensitiveness of blasthole diameter and the tunnel face area on blasting results in different blast design models. Using the software, it is quickly possible to determine specific charge, specific drilling and number of blastholes for each blast design model. The relations between both of blasthole diameters and the tunnel face area with the above parameters in different blast design models were then investigated to yield a set of equations with the highest correlations to compare the methods. The results showed that angular method requires more blasthole numbers than parallel method in similar condition(blasthole diameter and tunnel face area). Moreover, the specific charge values yielded by the two methods are approximately the same and very close together.

Energy release process of surrounding rocks of deep tunnels with two excavation methods

Numerical analysis of the total energy release of surrounding rocks excavated by drill-and-blast （D＆B） method and tunnel boring machine （TBM） method is presented in the paper. The stability of deep tunnels during excavation in terms of energy release is also discussed. The simulation results reveal that energy release during blasting excavation is a dynamic process. An intense dynamic effect is captured at large excavation footage. The magnitude of energy release during full-face excavation with D＆B method is higher than that with TBM method under the same conditions. The energy release rate （ERR） and speed （ERS） also have similar trends. Therefore, the rockbursts in tunnels excavated by D＆B method are frequently encountered and more intensive than those by TBM method. Since the space after tunnel face is occupied by the backup system of TBM, prevention and control of rockbursts are more difficult. Thus, rockbursts in tunnels excavated by TBM method with the same intensity are more harmful than those in tunnels by D＆B method. Reducing tunneling rate of TBM seems to be a good means to decrease ERR and risk of rockburst. The rockbursts observed during excavation of headrace tunnels at Jinping II hydropower station in West China confirm the analytical results obtained in this paper.

The Types of Tunnels Maintenance in Umbrella Arch Method

During tunneling in loose grounds, the ground deformation caused by drillings around the tunnel, leads to land subsidence and the adjacent tunnel which would affect tunnel structure and surrounding structures. In such situations it is necessary to improve the properties of the ground prior to drilling operations. In order to acquire tunnel face stability during excavation operations in areas with loose soil fault or areas with lack of adhesion, there are various methods such as split cross drilling, frame holder or auxiliary pre-holding methods such as umbrella arch method;pre-holding methods must provide safety when drilling and must be affordable, economically. In this study, we assessed the previous studies on methods and behaviors of umbrella arch strategy in reinforcing the concrete tunnels, reached the purpose with experimental and numerical methods and offered the latest design achievements, implementation progresses and analysis in relation with this method.

钻爆法机械化施工隧道随钻地震波超前地质探测技术研究

为适应我国隧道建设机械化、智能化、无人化发展趋势,围绕钻爆法机械化施工隧道,提出以凿岩台车破岩振动为震源的钻爆法机械化施工隧道随钻地震波超前地质探测技术。针对凿岩台车多震源连续激发带来的地震数据波场混叠、有效信息难以识别问题开展相关研究,提出VMD-SVD-RobustICA三臂混合先导信号分离方法与脉冲反褶积-小波域互相关地震记录重构方法,可实现三臂混合先导信号的分离与有效反射信号的提取。工程实践证明,利用凿岩台车搭载式无线高精度探测装备,该技术可初步实现“边钻边探”,降低预报环节对钻爆法机械化施工隧道正常施工带来的影响。最后,明确该技术目前存在的问题及解决思路。

高海拔铁路隧道斜井机械化配套与快速施工

为解决高海拔高寒地区斜井施工存在气压低、含氧量低、温差大、严寒干燥等问题,以某高海拔铁路隧道斜井工程为背景,结合围岩等级、断面大小、海拔高度,根据斜井施工机械化配套原则,提出高海拔陡坡长斜井机械化安全快速进洞施工工法,并选配超前支护、钻爆、装运、喷锚支护、衬砌等机械化作业线的成套设备。基于高度机械化的设备配套,提出“快挖、快运、快支”的高效施工技术以及各工序快速衔接工艺。以控制围岩变形为核心,构建一套积极干预加固围岩、注重早期支护并快速闭合的主动支护体系。结果表明:与普通钻爆法施工相比,采用三臂凿岩台车高度机械化配套施工效率高,月最快进尺为180 m,较人工钻爆法施工月进尺为130 m相比提高了近30%,施工质量稳定,作业人员投入少,且拱顶沉降和周边收敛均小于规范要求值,衬砌强度可靠,可实现高海拔小断面隧道“快挖、快支、主动支、快封闭”。

山区铁路隧道钻爆法施工安全风险演化路径及防控研究

山区铁路隧道钻爆法施工安全风险突出,探索安全风险演化路径并提出安全风险防控措施,对减少安全事故发生意义重大。针对山区铁路隧道钻爆法施工特点,运用文本挖掘分析历史安全事故资料、铁路标准规范资料、现场安全风险评估报告、相关研究文献资料等,结合“4M1E”理论和专家经验识别山区铁路隧道钻爆法施工主要安全风险因素和安全风险事件。采用质性分析法,结合现场调研和专家访谈,提取安全风险因素间、安全风险事件间、安全风险因素及事件间相互关系,构建山区铁路隧道钻爆法施工安全风险演化网络模型。基于风险演化理论、复杂网络理论等,利用度中心性、介数中心性、聚类系数、特征向量中心性、中间中心度等多项指标分析山区铁路隧道钻爆法施工安全风险演化网络节点重要度、边的关键性,从而确定关键链演化路径,并提出安全风险防控措施。研究结果表明:山区铁路隧道钻爆法施工安全风险包括人员、设备、技术、管理、环境5类共41个主要安全风险因素和塌方、突泥涌水等6个主要安全风险事件,确定了安全风险演化网络中8个关键节点、20条关键边和3条关键链,针对关键链风险演化路径提出了安全风险防控措施,为提高山区铁路隧道钻爆法施工安全风险管理水平提供参考。

Intelligent classification model of surrounding rock of tunnel using drilling and blasting method

Classification of surrounding rock is the cornerstone of tunnel design and construction.The traditional methods are mainly qualitative and manual and require extensive professional knowledge and engineering experience.To minimize the effect of the empirical judgment on the accuracy of surrounding rock classification,it is necessary to reduce human participation.An intelligent classification technique based on information technology and artificial intelligence could overcome these issues.In this regard,using 299 groups of drilling parameters collected automatically using intelligent drill jumbos in tunnels for the Zhengzhou-Wanzhou high-speed railway in China,an intelligent-classification surrounding-rock database is constructed in this study.Based on a machine learning algorithm,an intelligent classification model is then developed,which has an overall accuracy of 91.9%.Finally,using the core of the model,the intelligent classification system for the surrounding rock of drilled and blasted tunnels is integrated,and the system is carried by intelligent jumbos to perform automatic recording and transmission of drilling parameters and intelligent classification of the surrounding rock.This approach provides a foundation for the dynamic design and construction(both conventional and intelligent)of tunnels.

钻爆法施工隧道超挖对于混凝土超耗的定量关系研究

混凝土超耗居高不下是目前钻爆法施工隧道面临的形势和现状,在影响混凝土超耗的诸多因素中,超挖是其主要因素之一。本文通过大量的样本隧道,采用3D激光扫描仪测量设备,对隧道实际超挖进行实测;采用统计分析法、误差极限值法、对比分析法等数据分析方法,分析出隧道超挖的影响因素,计算因此造成的隧道混凝土超耗情况,从而得出隧道实际超挖与现行规范允许超挖的差距对混凝土超耗的影响程度,为隧道施工超挖控制提供借鉴。

钻爆法隧道下穿既有双连拱隧道施工技术研究

钻爆法隧道穿越新建既有双连拱隧道结构,下穿隧道为大跨度隧道,高度大、埋深较深,且在穿越既有隧道时,不能影响其安全运营和造成结构破坏,施工难度大、风险高。采用有限元软件Midas GTS NX对钻爆法隧道下穿既有隧道的变形和受力情况进行数值模拟计算,并研究了下穿施工前对上方隧道间地层采用大管棚和锚杆联合加固产生的效果。研究表明:未加固时,施工侧隧道结构的沉降要大于另一侧,呈现出“一峰二谷”变形形状,既有隧道上下部极易发生结构破坏。采用大管棚及锚杆联合加固,有效地转移了应力集中现象,降低了结构破坏风险,并且既有隧道沉降量仅为前者变化量的1/1.83,在控制标准以内。

西康高铁秦岭太兴山隧道凿岩台车钻爆试验研究

基于凿岩台车应用现状,针对采用凿岩台车钻孔爆破时平均线性超挖量大等问题,选取西康高速铁路(西安—安康)秦岭太兴山隧道左洞进口Ⅲ级围岩段(DK23+075—DK23+155)作为凿岩台车钻爆法试验段。首先针对周边孔外插角大和掏槽孔深度受限情况,将凿岩台车两侧机械臂长度由7.1 m缩短至6.1 m。然后制定了精准钻孔措施。基于与该隧道同等围岩级别地段手风钻钻孔爆破施工经验,经过现场3个循环的凿岩台车钻爆试验,确定掏槽形式为两级斜孔掏槽,把电子雷管起爆时间设置为导爆管雷管奇数段位的起爆时间,按照掏槽孔、辅助孔、内圈孔、周边孔和底板孔的顺序依次起爆。经实施,爆破施工进尺可达3.4~3.6 m,周边孔爆破后炮痕保留率90%以上,断面平均线性超挖量仅19.9 cm。与凿岩台车配套的药卷直径宜在40~45 mm取值。

单线隧道Ⅲ级围岩全断面不同爆破开挖工法对比

凿岩台车作为先进的隧道钻孔设备,钻孔速度快、施工安全和对环境友好,但是施工单位普遍使用积极性不高。依托秦岭太兴山长大高铁单线隧道爆破施工,综合对比分析研究了手风钻和凿岩台车2种钻爆施工方法的钻孔和装药效率、爆破超欠挖量、开挖成本、设备配件消耗费、折旧费、施工人员数量和安全性。结果表明:高铁单线隧道采用凿岩台车钻爆的施工效率低于手风钻,且凿岩台车爆破超挖量是手风钻的2倍以上,隧道爆破开挖总成本高于手风钻钻爆施工;但是凿岩台车施工安全性高,隧道掌子面施工环境友好,施工人员数量是手风钻的一半。最后指出凿岩台车钻爆是隧道爆破施工的趋势,给出了在人员培训和标准制定方面的一些建议。

基于改进云模型的隧道爆破效果综合评价研究

针对隧道爆破效果综合评价的不确定性问题,提出基于改进云模型与组合赋权的评价方法。结合现场工程经验与相关研究,选择平均线性超挖量、平均线性欠挖量、炮孔利用率、周边孔半孔痕率、大块率以及炸药单耗为评价指标,结合序关系分析(G1)法与基于指标相关性(CRITIC)法对各指标赋权,借助改进云模型对爆破效果数值及等级区间进行同向化处理,从而构建爆破效果综合评价模型。以某隧道为实例进行验证,模型分析结果表明在当前的爆破设计方案和生产水平下该隧道爆破效果的综合评价等级为“较好”,指明了影响爆破效果的主要因素,为进一步优化爆破设计参数提供了方向。

基于DEMATEL与系统动力学的隧道施工数字孪生应用效益分析

为推演钻爆法隧道施工数字孪生的应用在成本、效率、质量、安全4方面的投入与效益,分析复杂因素及相互依赖关系,提出一种DEMATEL(决策试行与评价实验室)方法和系统动力学结合的方法,对各方面指标的依赖关系进行解构与建模。首先,确定17个系统动力学模型行为指标与绩效评价指标;其次,采用DEMATEL方法定量分析指标之间的依赖关系和传递作用,并基于综合关系矩阵构建系统动力学模型复因果循环图(causal loop diagram, CLD),以降低系统动力学模型构建的主观性;最后,基于CLD以及云南某隧道实际数据,构建考虑多因素的隧道施工数字孪生效益分析系统动力学模型。结果表明:当机械成本小于7%洞身工程总造价时,施工效率显著下降,传感器与机械投入近似线性提高各项绩效,而信息化投入超过0.9%总造价后存在边界效应。

不同堵塞条件下硬岩隧道直眼掏槽破岩效果数值模拟研究

为研究不同堵塞材料及堵塞长度对硬岩隧道直眼掏槽爆破效果的影响,依托工程实例,采用ANSYS/LS一DYNA仿真模拟软件建立三维数值模型,对5种不同堵塞条件展开研究。根据数值模型计算结果,对掏槽区域爆破裂纹拓展情况进行了定性分析,对典型部位的岩石受力情况进行了定量分析。结果表明:1)自由面岩石主要受拉应力作用产生裂纹,炮孔堵塞使得爆炸荷载整体作用时间延长,致使自由面上裂纹更加密集;2)位于炸药和堵塞材料之间空气段附近的围岩,先受爆炸应力波作用岩石被压碎,后受力在拉压应力之间多次转化,致使裂纹被放大,结合爆生气体发挥的“气楔”作用,使得裂纹几乎贯穿模型截面;3)炮孔堵塞后炸药段周围岩石受到的爆生气体作用应力值显著提升,比不堵塞时的炸药段周围岩石峰值应力高出1.31~2.34倍,炮孔堵塞使得爆生气体持续稳定发挥作用时的压应力值提高3.70~4.70倍;4)以黏土和水作为堵塞材料时,堵塞长度为40cm的直眼掏槽破岩效果优于堵塞长度为60cm的效果。研究成果可为优化硬岩隧道直眼掏槽爆破参数提供理论基础。

铁路隧道钻爆法与盾构法施工碳排放强度分析

采用全生命周期理论,建立铁路隧道工程物化阶段和运营维护阶段碳排放核算模型。对隧道全生命周期进行数据收集和清单整理,实现碳排放量核算。对铁路隧道施工中的钻爆法和盾构法进行生命周期碳排放强度比较,结果表明钻爆法施工碳排放强度为16 785 tCO_(2e)/km,盾构法施工碳排放强度为9 184 tCO_(2e)/km,为钻爆法施工的54.7%。进一步分析表明盾构法施工水泥、钢材等材料用量及化石能源消耗量远低于钻爆法施工,直接碳排放量和其他间接隐含碳排放较少。研究对降低铁路隧道工程碳排放、推动铁路行业低碳发展具有重要参考价值。

Tracking of horizontal alignment of the long and large diameter uncharged hole in NATM tunnel

The long and large diameter uncharged hole boring(LLB)method is a cut blasting method that minimizes blast-induced vibrations by creating long and large diameter uncharged holes at the excavation face of tunnels prior to tunnel excavation.Drilling in this method typically uses a 50 m long with a 382 mm diameter hammer bit in the horizontal direction at the tunnel face.However,the significant weight and uni-directional rotation of the rod head,as well as variables such as geological characteristics,machine conditions,and inexperienced operators result in significant deviation from the target borehole alignment that hinders the vibration-dampening effect of the uncharged holes.Furthermore,since there is no method to verify the alignment of the boreholes until main tunnel construction,borehole misalignment is often not discovered until weeks after construction,which requires tunnel construction to cease until the equipment can be remobilized and an additional borehole be created,causing significant delays and increased costs for the entire tunnel project.In this study,the borehole alignment tracking and ground exploration system(BGS)is developed to predict and monitor the quality and alignment of boreholes for cut blasting methods such as the LLB methods immediately after boring.The BGS was subsequently tested at a subway construction site to evaluate its performance in the field.The measurements yielded by the BGS were compared with manually measured boring positions at every 5 m along the borehole.Although the BGS showed a maximum deviation of approximately 12%at a local point where the hole surface was relatively rough,the accuracy for the final boring position was approximately 97%,demonstrating excellent precision of the alignment tracking system.The BGS demonstrates excellent performance in predicting ground conditions and the boring quality of a cut hole immediately after drilling,and shows promise in various other applications for monitoring borehole alignment.

钻爆法隧道上台阶爆破炮孔装药量精细计算方法

目前隧道钻爆法施工技术日趋成熟,但炮孔装药量的精细计算仍缺乏可靠的经验或理论公式。基于利文斯顿爆破漏斗理论,考虑隧道上台阶爆破方案设计中的炮孔孔距、排距和倾角等因素,提出了倾斜与垂直炮孔负担爆破岩石体积的计算方法。考虑岩石坚固性系数、爆生临空面方向等因素的影响,建立了炸药单耗优化计算方法。最后,基于炮孔装药量经验体积计算公式,提出了隧道上台阶爆破炮孔装药量精细计算的方法。依托临沂至滕州高速公路寨山隧道开挖试验段,验证了炮孔装药量计算方法的可靠性,研究成果对指导隧道精细爆破具有重要意义。

管片分块对钻爆法隧道装配式衬砌受力影响

为研究管片分块不同对钻爆法公路隧道装配式衬砌受力性能的影响,文中以某高速公路隧道项目试验段为依托,通过建立隧道结构的有限元模型,分析不同管片分块、不同管片接头刚度对装配式衬砌结构受力性能的影响。结果表明随着接头抗弯刚度增大,管片轴力略有降低,最大轴力出现在拱脚部位;随着衬砌管片分块数增大,最大轴力、最大位移和最大转角均有所增大,最大正/负弯矩略有减小;管片接缝截面均处于受压状态时,对结构受力及接缝防水均较为有利。研究可为类似工程的衬砌受力性能分析提供参考。