青岛地铁6号线复杂地质条件盾构/TBM选型分析

在隧道建设过程中,合理的盾构/TBM选型可以保证工程的安全顺利进行,还能够节约成本、节省工期。以青岛地铁6号线8工区为背景,针对该地区复杂的地质条件,对盾构/TBM选型、刀盘结构、刀具选型、成本等进行了分析;最后通过工程现场得到的扭矩、推力等参数对选型的合理性进行了评估。结果表明:1)采用带有面板式刀盘的双护盾TBM能够适应该工区的微风化斜长片麻岩地层,采用带有复合式刀盘的土压平衡盾构能够适应该工区的强风化斜长片麻岩地层以及复合地层;2)19英寸(48.26 cm)滚刀在该工区的微风化斜长片麻岩地层有较强的适应性,刮刀与18英寸(45.72 cm)滚刀在该工区的强风化斜长片麻岩地层和复合地层有较强的适应性。该分析可以为青岛等地区复杂地质条件下的盾构/TBM选型和施工提供参考和借鉴。     

基于熵权-功效系数法的岩爆烈度分级预测研究

岩爆是高地应力区开挖过程中常遇到的工程地质灾害,发生突然且破坏性极大,因此岩爆的预测一直是岩爆课题的研究热点。在综合分析岩爆影响因素的基础上,选取切向应力与单轴抗压强度比值σθ/σc、岩石脆性系数σc/σt、围岩弹性储能Wet及岩石完整性系数Kv作为评价指标,将熵权法与功效系数法进行结合,采用熵权法确定各指标权重,并利用功效系数法进行综合评价,从而建立出岩爆预测的熵权-功效系数法模型。利用国内外17组典型工程实例对模型进行验证,将所得结果与功效系数法、熵权-正态云模型、RS-TOPSIS模型预测结果及实际情况进行对比。为进一步考查模型的适用性,利用该模型对猴子岩水电站及锦屏二级水电站进行岩爆烈度等级预测。研究结果表明,熵权-功效系数法模型能够综合考虑影响岩爆发生的主要因素,预测准确性较高且原理简单易懂,具有一定的工程运用前景。     

TBM刀盘推力与扭矩预测方法分析

通过分析TBM在施工推进中的受力组成,在此基础上,运用滚刀受力模型理论和经验公式计算刀盘推力、扭矩,并将其应用于实际工程隧道的TBM刀盘推力与扭矩预测。以实际工程为例,运用滚刀受力预测公式计算TBM刀盘推力和扭矩,并将理论计算值与TBM现场监测数据进行对比分析,结果表明:运用Rostami模型公式能够较准确地预测TBM刀盘推力和扭矩,适用于硬岩地质条件下TBM掘进参数预测,为TBM设计选型提供一定的理论指导。     

重庆地铁六号线一期工程TBM法施工技术

重庆轨道交通六号线一期工程是国内首次采用TBM法施工的城市地铁工程.本文通过重庆轨道交通六号线一期工程的施工,对TBM施工适应性进行了分析、比较详细地介绍了TBM设备选型及其关键施工技术.     

川藏铁路TBM施工适应性探讨及选型

国家重点工程川藏铁路开工在即,为提高中国复杂地质条件下长大隧道TBM施工技术水平,缩短工程建设周期,川藏铁路将选择条件适宜的隧道工程利用TBM进行施工。TBM施工具有机械集成度高、安全快速的优点,但也存在地质适应性弱的短板,目前具体哪座隧道采用TBM施工存在着较大争议。在对国内外类似施工情况调研的基础上,结合现在已经掌握的川藏铁路地质资料,研究各类TBM对不同地质条件的适应性,做出正确的选型,将是决定工程成败的关键。     

功效系数法在隧道围岩失稳风险预警中的应用

为了对隧道围岩危险性做出准确判断,以便于现场及时采取相应工程措施,预防围岩失稳灾害的发生,将功效系数法应用于隧道围岩的稳定性评价中,对围岩失稳风险进行预警.选取岩石的单轴饱和抗压强度Rc、岩石质量指标RQD、岩体完整性系数Kv、结构面强度系数Kf、地下水作用指标、洞轴线与主要结构面的夹角q 作为评价指标,采用专家评估法确定各指标的权重系数,建立隧道围岩失稳风险预警模型.根据总功效系数的大小,将围岩失稳险情划分为巨警、重警、中警、轻警和无警5个警限.然后,运用所建预警模型对浙江省诸永高速公路西华岭隧道围岩危险性进行判断.研究结果表明:运用功效系数法对围岩危险性进行警情预测,比较符合实际,且简单易行,不失为隧道围岩稳定性评价和失稳风险预警的一种新方法,具有较高的工程应用价值.     

基于UMT的引水隧洞TBM地质适应性分析

在隧洞施工过程中,地质问题起着明显作用,其地质的好坏直接决定施工方法的选择。隧洞施工建设影响因素较多,地质对机械施工的影响有很多不确定性。为明确地下建设过程中TBM施工与地质是否相适应,运用未确知测度理论(UMT)建立TBM施工地质适应性评价模型。以北疆供水二期工程喀双段引水隧洞项目为例,选取破碎带宽、涌水量、透水率、地温等11个影响因子作为未确知测度理论的判别指标,将11个TBM施工地质适应性评价指标代入单指标测度函数中得到单指标测度评价矩阵,结合熵权法以及灰色关联理论得到各个指标的权重,利用置信度识别准则进行等级评判,最后得出TBM施工地质适应性分析评价结果。将评价结果与现场实际情况做对比分析,结果与实际相符,证明该方法有效,可以在实际工程中推广应用。     

规划地块的机械式停车设备适应性研究

针对规划地块的机械式停车设备适应性问题,利用多目标决策方法和系统分析思想,从工程经济性、技术可行性、环境适应性和用地适应性4方面建立指标体系并构建了基于灰色关联分析法的机械式停车设备适应性分析模型,为各类机械式停车设备的选型提供理论依据。该模型使用简单、指标确定灵活,采用定量分析方法,有效克服了成本分析法和加权因素分析法考虑因素单一、主观性强的缺点。     

基于掘进性能的TBM施工围岩综合分级方法

传统围岩分级方法侧重于围岩的稳定性,对于TBM施工隧道工程,围岩与TBM均扮演重要角色,有必要建立一套服务于TBM隧道工程的围岩分级新方法。依托引汉济渭引水隧洞工程的现场数据,对场切深指数FPI与地质参数、掘进参数的相关性进行分析,建立TBM隧道的围岩可掘性分级;对影响TBM利用率的主要地质因素进行分析,建立TBM隧道的适应性分级。综合考虑工程的围岩可掘性及TBM适应性,以施工速度为指标,建立基于掘进性能的TBM施工围岩综合分级。分级选取岩石强度、岩体完整性、地下水状态、初始地应力状态、隧道轴线与主要软弱结构面夹角等5方面因素指标,对TBM推力、贯入度、利用率和施工速度进行影响关系综合分析。结果表明,新建立的TBM施工围岩综合分级方法可以进行TBM掘进性能预测与工期、成本分析,有效解决开敞式TBM工程实用围岩分级问题。     

基于功效函数法的大流动度混凝土配合比优化研究

采用功效函数法对大流动度混凝土的多项性能指标进行综合评定以实现对配合比的优化。利用数理统计中的变异系数法计算各参数权重,分别赋予大流动度混凝土的工作性、耐久性和力学性能3个参数多项性能指标在配合比中的权重,采用功效系数法将多项指标统一为无量纲的单一指标,根据计算出的总功效函数值,评价所设计的大流动度混凝土的综合性能。正交试验结果表明,采用功效系数法可以直观准确地评价混凝土综合性能,优化结果满足规范和设计要求。     

Geotechnical risk assessment based approach for rock TBM selection in difficult ground conditions

There are many potential sources of geotechnical risk in mechanized rock tunnelling. Problems such as encountering fault zones with running and water bearing gouge, tunnel walls instabilities in running or blocky grounds, hard and abrasive rock sections and convergent tunnel sections are principal causes in geotechnical risk occurrence. On the other hand, the performance of each TBM encountering such conditions will be different. Therefore, using different TBMs will have variable risk levels. This paper is to discuss rock TBM selection based on geotechnical risk minimization. So, a new approach was proposed based on decision analysis using decision tree. Based on the newly proposed approach, the most appropriate TBM is one that has the minimum risk level either before or after hazards mitigation measures. To be able to check the performance of this approach in practice, selection of machine for Nosoud water transfer tunnel has been evaluated. A shielded TBM (either single or double shield one) was proposed for the tunnel based on the newly proposed method. However, a double shield TBM was selected because of its more flexibility in difficult ground conditions in comparison with single shield TBM and limitation of project construction duration. The machine performance during tunnelling period verifies the success of excavation using selected TBM.     

城市轨道交通隧道双护盾TBM施工适应性研究

双护盾TBM施工具有速度快、安全性高等优点,已成为山岭隧道建设的重要选择。通过对已建的双护盾TBM隧道调研得到了双护盾TBM施工中常见的问题,并结合青岛地铁2号线提出了基于地质适应性、线路适应性、周边环境适应性的双护盾TBM城市轨道交通隧道适应性分析方法。研究得出了以下结论:采用双护盾TBM施工的隧道多为特长、深埋隧道,施工过程中受高地应力和地下水影响,经常发生卡机、涌水、渗水等灾害;和山岭隧道相比,城市轨道交通隧道采用双护盾TBM施工时灾害发生率更低且处治措施更为灵活;双护盾TBM施工技术在城市轨道交通隧道建设中具有速度快、对环境影响小的优点;针对施工过程中出现的回填层质量较差和TBM过站与车站施工协调难度大的新问题提出了设置止浆环和曲线过站的处治方式。     

300m小半径曲线隧道单工作井内盾构整体始发技术

大连市地铁二号线西安路站-交通大学站区间，其两端车站均没有盾构始发条件，盾构始发井设在距离西安路站约150m的区间隧道上，在300m的小半径曲线条件下采用割线始发模式，先施工盾构机后部70m矿山法隧道，在单工作井内采用盾构整体始发技术，提高了出渣和运输管片速度，缩短了施工工期，降低了施工成本。     

Application of non-linear regression analysis and artificial intelligence algorithms for performance prediction of hard rock TBMs

Prediction of machine performance is an essential step for planning, cost estimation and selection of excavation method to assure success of tunneling operation by hard rock TBMs. Penetration rate is a principal measure of TBM performance and is used to evaluate the feasibility of using a machine in a given ground condition and to predict TBM advance rate. In this study, a database of TBM field performance from two hard rock tunneling projects in Iran including Zagros lot 1B and 2 for a total length of 14.3 km has been used to assess applicability of various analysis methods for developing reliable predictive models. The first method used for this purpose was principal component analysis (PCA) which resulted in development of a set of new empirical equations. Also, two Soft computing techniques including adaptive neuro-fuzzy inference system (ANFIS) and support vector regression (SVR) have been employed for this purpose. As statistical indices, root mean square error (RMSE), correlation coefficient (R²), variance account for (VAF), and mean absolute percentage error (MAPE) were used to evaluate the efficiency of the developed artificial intelligence models for TBM performance prediction. The results of the analysis show that AI based methods can effectively be implemented for prediction of TBM performance. Moreover, it was concluded that performance of the SVR model is better than the ANFIS model. A high correlation was observed between predicted and measured TBM performance for the SVR model. This study shows the feasibility of using these systems and subsequent work is underway to expand the database of TBM field performance and use the aforementioned methods to develop a more comprehensive TBM performance prediction model.     

复合地层双模盾构适应性及掘进参数研究

依托南宁市轨道交通5号线五一立交站—新秀公园站区间隧道工程,论述了土压–泥水双模盾构的选型依据,基于区间右线双模盾构及左线泥水盾构的现场掘进试验数据,详细对比分析不同地质段和不同模式段的掘进参数变化及能源消耗情况,得出相比于单模式盾构,双模盾构在复合地层条件下的适应性。研究结果表明:始发段由粉土、粉细砂与圆砾组成的复合地层中采用的泥水平衡模式严格控制地面沉降,在过江段所在的全断面粉砂质泥岩和泥质粉砂岩复合地层中,土压模式有效规避了泥水盾构易固结泥饼的风险;掘进速率方面,右线双模盾构相对于左线掘进速率增幅达181.44%;能源消耗方面,右线双模盾构的盾尾油脂消耗、水消耗及电消耗较左线分别减少了7.87%,30.32%,30.64%。     

Risk analysis using fault-tree analysis (FTA) and analytic hierarchy process (AHP) applicable to shield TBM tunnels

In this paper, the potential risk of undesirable events occurring during tunneling with application of a shield tunnel boring machine (TBM) method is discussed along with the risk analysis which can systematically assess overall risk levels. Potential risks and typical scenarios pertaining to shield TBM tunnels have been investigated based on previous case histories and correspondence with experts. The relevant risks from undesirable events were categorized into four groups: cutter-related malfunction, machine blockage or hold-up, mucking problems that hinder transporting excavated materials, and segment defects. A fault-tree set was constructed by grouping risk factors (or causes) into geological, design and construction/management factors. Risk analysis was performed by adopting fault-tree analysis (FTA) and an analytic hierarchy process (AHP) with consideration of the probability and impact of the risks. In addition, the proposed method was reliably validated by comparison with field observation, and thus indicates its applicability to risk management for shield TBM tunneling.     

深部高应力隧道TBM护盾长度和推力计算方法研究

岩石隧道掘进机(TBM)法开挖长隧道是一种安全、快速、有效的隧道开挖方法,但TBM复杂高应力隧道掘进时易发生卡机事故,因此,TBM在设计之初应尽可能考虑地质环境的影响,降低TBM的卡机风险。通过分析高应力常规地层和高应力软弱破碎地层对TBM的影响,提出了高应力常规地层和高应力软弱破碎地层TBM卡机的两个判据。根据两个判据提出了考虑围岩力学参数的高应力隧道TBM护盾长度设计和推力设计理论计算方法,并给出了参数选取依据。最后依据西南地区某高应力隧道的实际围岩地质参数,计算分析了现有TBM设计的合理性。本研究可为TBM的盾体长度和推力设计计算提供围岩力学参数依据。     

考虑回填层的护盾式TBM隧道结构设计方法研究

回填层作为管片与围岩之间的传力层对管片受力有着重要的影响,而现行护盾式TBM隧道设计方法均忽略了回填层的影响,与工程实际存在一定的差异。研究考虑了护盾式TBM隧道中回填层的实际分布,推导了回填层-围岩等效抗力系数计算公式,并以此建立了TBM隧道管片结构设计模型。研究得出:由于回填层的存在,围岩-回填层的等效抗力系数与围岩抗力系数存在一定的差别,围岩抗力系数的改变程度与围岩、回填层力学参数比有关;回填层在管片背后分布呈"上厚下薄"状,使得管片背后围岩-回填层弹性抗力系数分布不同,Ⅱ级围岩回填层-围岩弹性抗力系数呈"上小下大"的鸭蛋状,Ⅲ,Ⅳ级围岩近乎圆状,Ⅴ级围岩呈"上大下小"的倒鸭蛋状;基于回填层-围岩等效抗力系数的结构设计模型计算出的管片受力结果与现场试验值更加接近,验证了回填层-围岩等效抗力系数计算方法和设计模型的准确性。     

Thrust force requirements for TBMs in squeezing ground

Rapidly converging ground may exert such a high pressure on the shield that the thrust force is no longer sufficient to overcome shield skin friction and the TBM becomes jammed. This paper advances a number of theory-based decision aids, which will support rapid, initial assessments to be made of thrust force requirements. A comprehensive parametric study has been carried out using the finite element method and, based on the numerical results, dimensionless design nomograms have been worked out that cover the relevant range of material constants, in situ stress and TBM characteristics. The nomograms make it possible to assess the feasibility of a TBM drive in a given geotechnical situation and to evaluate potential design measures or operational measures such as reductions in shield length, the installation of a higher thrust force, increases in the overcut or the lubrication of the shield surface, thus making a valuable contribution to the decision-making process.     

锦屏二级水电站TBM选型及施工关键技术研究

 锦屏二级水电站引水隧洞属于深埋特长隧洞,其中2条引水隧洞施工采用敞开式硬岩掘进机(TBM)进行施工。引水隧洞TBM开挖直径12.4 m,位列世界第二。引水隧洞穿越区域水文地质条件复杂,开挖中面临地下水预报及处理、通风、岩爆防治等三大关键技术问题。通过对大量文献资料和工程实例的研究,概述TBM近半个世纪的发展及其在隧道建设中的应用现状和主要问题。对锦屏二级水电站区域地质条件以及主要的工程地质问题进行分析,结合国内外已有的TBM施工经验,对锦屏二级TBM选型以及在施工中面临的超前地质预报、围岩稳定、高地应力及岩爆、突涌水、溶洞、有害气体、断层破碎带等不良地质条件所采用的施工方法进行分析研究,针对性地提出在各种不良地质条件的下的TBM施工对策,对锦屏二级水电站TBM施工提出建议,研究成果可供类似工程参考。