新型盘式削片机刀盘结构设计及切削力研究

基于目前纤维板所需工艺木片的生产现状,为保证盘式削片机生产工艺木片的质量并解决盘式削片机飞刀快速更换的问题,设计一款采用差动螺旋结构实现飞刀伸出量微调,以及刀块整体更换的新型盘式削片机刀盘。对新型刀盘的削片工作原理以及切削力进行研究,对装刀块夹持力部分进行验证计算,通过Adams仿真软件对设计的新型刀盘进行了动力学分析,验证刀盘结构在额定转速下的稳定性。

基于克里金插值法的常压刀盘刀梁区域泥饼发育程度算法及应用研究

为解决刀盘结泥饼影响盾构施工进度的问题,以某泥水盾构刀盘为研究对象,展开对刀盘刀梁部位泥饼发育程度的研究,提出一种基于克里金插值法的常压刀盘刀梁区域泥饼发育程度算法,并进行应用案例研究。利用全刀盘布置温度传感器获取刀盘温度数据,选取线性插值扩展刀梁区域温度数据,运用克里金插值法进行全刀盘区域的温度仿真计算,结合空间和时间2个维度分析刀盘在正常掘进、外侧结泥饼及内侧结泥饼3种工况下的判断条件,提出分离相邻测温点正/负差值,以刀盘整体正/负差值之和呈现同方向变化作为泥饼发育初始环评判指标;结合所建温度场,引入从泥饼发育初始环到当前环的温度变化率总和作为泥饼发育程度评判指标。针对某大直径常压刀盘泥水盾构案例进行分析判定,对比采用反距离权重插值法、克里金插值法和扩展样本克里金插值法构建的3种温度场用于泥饼发育程度计算,结果表明扩展样本后的克里金插值法的适用性最强,并与工程实际情况进行对比,准确率达70.87%。

全断面竖井掘进机锥形刀盘破岩机理研究

刀盘刀具系统作为全断面竖井掘进机的关键组成部分,不同刀盘锥度及刀间距对滚刀破岩起决定性的作用。运用ABAQUS软件建立滚刀动态破岩模型,分析不同刀盘锥度和不同刀间距对滚刀破岩的影响,并获取了滚刀在破岩过程中的受力情况及破岩效率。结果表明:滚刀破岩效率随着刀盘锥度的增大而减小,滚刀破岩效率随着滚刀安装半径的增大而减小,综合滚刀受力、破岩效率和实际工况,得到刀盘锥度为120°、滚刀刀间距为40 mm时,滚刀破岩效率最高。为竖井掘进机锥形刀盘设计提供了理论依据,有效提高了竖井掘进机破岩效率和整机研制水平。

TBM刀盘连接螺栓载荷工况及其连接可靠性技术

针对TBM在掘进过程中存在刀盘连接螺栓易断裂问题,文中对TBM刀盘直径与主轴承选型,以及刀盘连接螺栓连接可靠性进行研究。以某隧道工程为依托,首先通过建立TBM刀盘受力模型,进一步分析了刀盘连接螺栓在4种复杂工况下所承受的载荷;其次对刀盘连接螺栓的疲劳强度进行校核,为主轴承选型提供理论原则与依据;最后通过ANSYS仿真软件分别分析了刀盘连接螺栓受力模型优化前与优化后螺栓的结构强度与刚性。结果表明:优化后螺栓受到的最大应力减小46.3%,总变形量减小8.6%。同时验证:在主轴承偏小的情况下,刀盘连接螺栓在脱困工况下最容易断裂。

盾构机刀盘泥饼性能及机械臂攀附试验研究

由于泥饼的长期附着,盾构机刀盘和刀具工作负荷会逐渐增加,该状况常常使掘进参数出现突变,大大降低施工效率。盾构机泥饼人工清理困难。文中通过对试验室环境下制备泥饼的形成过程和机理进行分析,并对泥饼的物理性能进行测试。通过微型十字板剪切仪、固结试验及机械手臂对泥饼攀附试验研究了胶结强度对其力学性能的影响。研究发现泥饼式样呈现出中压缩性,初始胶结强度影响泥饼式样在剪切过程中的剪胀性,影响着泥饼的抗剪强度。泥饼式样的抗剪强度为85kPa时,机械手臂能够攀附在泥饼表面。因此爪尖数量的增加以及泥饼抗剪强度的提高,能够有效提高机械臂的攀附状态,进一步为机械手臂搭载清淤装备攀附泥饼提供了力学依据。

砂卵石地层大直径盾构施工的关键技术

[目的]总结分析砂卵石地层大直径盾构施工中盾构机选型、盾构始发与接收、盾构掘进姿态控制等施工关键技术,并提出具体的施工控制参数与施工控制措施,以减轻刀盘刀具磨损、降低地层损失、减小地层沉降变形。[方法]针对砂卵石地层结构松散、颗粒无胶结或弱胶结、颗粒粒径大、透水性强的工程结构特性,采用理论分析、现场监测等方法,从盾构机选型、盾构始发接收、盾构掘进姿态控制、盾构刀盘刀具的检测维修等方面深入分析砂卵石地层大直径盾构施工关键技术。[结果及结论]大直径盾构的刀盘开口率、刀盘刀具类型、渣土改良方案等应根据地层结构特性进行特殊设计,且有利于盾构排渣和超前切割;盾构井端头宜采取地层注浆加固、大管棚支护、施工降水等综合加固措施以保证大盾构始发或接收时地层的稳定;大直径盾构的掘进施工应重点控制刀盘转速、出渣量、出渣温度等参数,并应适当增大注浆量,提高渣土改良效果,避免过大超挖,保证地层损失处于合理范围内。采用上述施工参数与施工措施后,盾构掘进风险可控,施工质量与施工效率明显提升,同时大大降低了施工成本。

基于数值仿真技术的TBM刀盘系统强度可靠性分析

刀盘作为全断面岩石隧道掘进机(Full Face Rock Tunnel Boring Machine,TBM)的直接开挖部件,承受刀具破岩的全部载荷,其强度可靠性是评价TBM刀盘性能的重要指标。受复杂地质条件及刀岩相互作用机制的影响,刀盘在掘进过程中承受的载荷具有很强的随机性,故在单一特定工况下研究刀盘的强度性能已无法满足工程需求。鉴于此,本文建立一套随机载荷作用下TBM刀盘强度可靠性的分析方法。基于刀盘-岩石耦合计算模型获取掘进过程中刀具的破岩载荷;对破岩载荷进行统计分析,得到其分布特性及对应参数,并以此为依据构造刀具破岩的随机载荷,采用蒙特卡罗法对刀盘强度的可靠性进行分析。结果表明:安装半径最大的两把正滚刀的破岩载荷对刀盘强度失效的影响最为显著,其权重可达2/3;在常规岩层下高速施工或在硬岩地层维持正常开挖速度,都将显著降低刀盘的强度可靠性。研究结果可为刀盘的地质适应性设计及TBM施工参数控制提供参考。

完整极硬岩条件下TBM连续高效破岩技术

以某项目螺旋斜坡道工程为背景,分析了影响TBM在完整极硬岩条件下连续高效掘进的因素,提出设计高效耐磨的刀盘系统,具体包括将刀间距优化至60 mm、刀具额定荷载提升至375 kN、提高刀座强度和耐疲劳性、设置两路冷却系统以控制刀盘刀具温度,并重点强化了刀盘的耐磨性;减小刃宽保证贯入度,将边刀刀圈允许磨损部分外侧加厚2.5 mm。在辅助破岩措施上,控制爆破实现人造裂隙;在连续转弯破岩技术环节上,提高TBM主轴承强度,并不断优化掘进参数进一步提高掘进效率。实践应用效果良好。

On the Loads for Strength Design of Cutterhead of Full Face Rock Tunnel Boring Machine

Cutterhead loads are the key mechanical parameters for the strength design of the full face hard rock tunnel boring machine(TBM).Due to the brittle rock-breaking mechanism,the excavation loads acting on cutters fluctuate strongly and show some randomness.The conventional method that using combinations of some special static loads to perform the strength design of TBM cutterhead may lead to strength failure during working practice.In this paper,a three-dimensional finite element model for coupled Cutterhead–Rock is developed to determine the cutterhead loads.Then the distribution characteristics and the influence factors of cutterhead loads are analyzed based on the numerical results.It is found that,as time changes,the normal and tangential forces acting on cutters and the total torque acting on the cutterhead approximately distribute log normally,while the total thrusts acting on the cutterhead approximately show a normal distribution.Furthermore,the statistical average values of cutterhead loads are proportional to the uniaxial compressive strength(UCS)of cutting rocks.The values also change with the penetration and the diameter of cutterhead following a power function.Based on these findings,we propose a three-parameter model for the mean of cutterhead loads and a method of generating the random cutter forces.Then the strength properties of a typical cutterhead are analyzed in detail using loads generated by the new method.The optimized cutterhead has been successfully applied in engineering.The method in this paper may provide a useful reference for the strength design of TBM cutterhead.

A Closer Look at the Design of Cutterheads for Hard Rock Tunnel-Boring Machines

在隧道项目中,隧道掘进机(TBM)能否顺利施工取决于TBM系统所有部件(从刀具到后备系统)能否正常运转,并取决于全部机车车辆的配合。而在整个TBM系统中,刀盘是影响TBM施工效率最为关键的因素。刀盘的设计影响到掘削效率、刀盘平衡、刀具使用寿命、主轴承/齿轮箱维护、出渣效果、面刀和边刀/排渣铲斗的磨损情况。总体来说,刀盘设计对掘进速度(ROP)、机器利用率(U)及每日进尺(AR)有重要影响。尽管当前可用文献中已就盘形滚刀、切削力、刀盘的某些设计特征做了讨论,但与本论题相关的文献却十分有限,这是因为刀盘的设计主要由隧道掘进机制造商负责,大部分设计工艺都属制造商专有,虽然本论题当前大受关注,但岩石隧道掘进机的设计对终端客户而言仍是个谜题。本文将试着阐明设计中的基本概念,虽不足以帮助读者进行成熟设计,却可助工程师与承包商理解设计步骤中的构思过程、合理设计中应注意的事项以及刀盘设计对于隧道掘进机运行及寿命周期的意义。

Optimal design of structural parameters for shield cutterhead based on fuzzy mathematics and multi-objective genetic algorithm

In order to improve the strength and stiffness of shield cutterhead, the method of fuzzy mathematics theory in combination with the finite element analysis is adopted. An optimal design model of structural parameters for shield cutterhead is formulated,based on the complex engineering technical requirements. In the model, as the objective function of the model is a composite function of the strength and stiffness, the response surface method is applied to formulate the approximate function of objective function in order to reduce the solution scale of optimal problem. A multi-objective genetic algorithm is used to solve the cutterhead structure design problem and the change rule of the stress-strain with various structural parameters as well as their optimal values were researched under specific geological conditions. The results show that compared with original cutterhead structure scheme, the obtained optimal scheme of the cutterhead structure can greatly improve the strength and stiffness of the cutterhead, which can be seen from the reduction of its maximum equivalent stress by 21.2%, that of its maximum deformation by 0.75%, and that of its mass by 1.04%.

Real-time analysis and prediction of shield cutterhead torque using optimized gated recurrent unit neural network

An accurate prediction of earth pressure balance(EPB)shield moving performance is important to ensure the safety tunnel excavation.A hybrid model is developed based on the particle swarm optimization(PSO)and gated recurrent unit(GRU)neural network.PSO is utilized to assign the optimal hyperparameters of GRU neural network.There are mainly four steps:data collection and processing,hybrid model establishment,model performance evaluation and correlation analysis.The developed model provides an alternative to tackle with time-series data of tunnel project.Apart from that,a novel framework about model application is performed to provide guidelines in practice.A tunnel project is utilized to evaluate the performance of proposed hybrid model.Results indicate that geological and construction variables are significant to the model performance.Correlation analysis shows that construction variables(main thrust and foam liquid volume)display the highest correlation with the cutterhead torque(CHT).This work provides a feasible and applicable alternative way to estimate the performance of shield tunneling.

A New System to Evaluate Comprehensive Performance of Hard-Rock Tunnel Boring Machine Cutterheads

The accurate performance evaluation of a cutterhead is essential to improving cutterhead structure design and predicting project cost. Through extensive research, this paper evaluates the performance of a tunnel boring machine(TBM) cutterhead for cutting ability and slagging ability. This paper propose cutting efficiency, stability, and continuity of slagging as the evaluation indexes of comprehensive cutterhead performance. On the basis of research of true TBM engineering applications, this paper proposes a calculation method for each index. A slagging efficiency index with a ratio of the maximum di erence between the slagging amount and average slagging is established. And a slagging stability index with a ratio of the maximum slagging fluctuation and average slagging is presented. Meanwhile, a cutting efficiency index by the weighed average value of multistage rock fragmentation of a cutter’s specific energy is established. The Robbins and China Railway Construction Corporation(CRCC) cutterheads are evaluated. The results show that under the same thrust and torque, the slagging stability of the CRCC scheme is worse, but the slagging continuity of the CRCC scheme is better. The cutting ability index shows that the CRCC cutterhead is more efficient.

Evaluation of TBM Cutterhead’s Comprehensive Performance Under Complicated Conditions

A comprehensive performance evaluation method for the tunnel boring machine(TBM)cutterhead is proposed in this paper.The evaluation system is established on strength and vibration.Based on fracture mechanics theory,fatigue strength evaluation indices are determined under critical crack length.The concept of crack regions division is proposed to evaluate fatigue strength more accurately and specifically.In addition,the velocities in three directions of critical locations are obtained with dynamics equations.Then,the root-mean-square values of velocities are taken as the vibration severity indices.Taking the cutterhead of Jilin diversion engineering as an example,the evaluations of each index are completed;then,the vibration of the TBM cutterhead is measured and compared with the theoretical calculation results.There are similar change laws between the theoretical calculation results and the testing results of the cutterhead acceleration,which proves that the method of calculation of the vibration index is effective,the reliability of the cutter saddle welding should be paid attention to when the TBM is working,and the condition of vibration severity of the TBM cutterhead meets the requirements but needs to be improved.

盾构切削桩基研究现状综述

为厘清盾构切桩的发展脉络,全面掌握其应用及发展情况,综述了国内外盾构切削桩基技术的研究现状。首先,基于文献计量分析对盾构切桩相关文献的热点关键词和发展趋势进行分析,归纳总结盾构切桩领域的研究热点及研究进展。其次,在此基础上分别从盾构改造、掘削参数优化、盾构切桩引起的地层响应和桩基承载力研究3个方面综述当前最新研究成果。最后,对盾构切削桩基的主要研究方法、研究机制、适用范围及优缺点进行归纳总结,探讨有待解决的主要问题以及未来重点研究方向。结果表明:1)10余年来盾构切桩技术发展迅速且取得了良好的切桩效果及经济效益反馈,切桩技术已相对成熟;2)刀具参数及布置方式尚没有明确的确定方法,在复杂地质条件下,仍存在刀具磨损和钢筋缠绕刀盘的现象;3)由于混凝土脊破裂面产生的机制尚不明确,且已有的计算方法未考虑混凝土强度的影响,刀间距设计多依赖已有的工程经验;4)盾构切桩掘削参数的选取多是基于数值模拟和室内试验,对实际工况都进行一定程度的简化,难以反映切桩过程中盾构与桩基相互作用的复杂效应;5)推力和转矩计算模型的公式简化条件不尽相同、侧重点各不相同,公式的推广性和适用性还需进一步提高;6)目前对切桩引起的地表沉降以及控制措施研究较多,影响机制方面的研究还较少。

Evaluation Method for Tunneling Stability of TBM Cutterhead

In the process of tunneling of tunnel boring machine (TBM), different geological conditions often correspond to different working conditions, and the randomness of geological conditions also causes the order of occurrence of each working condition to be different. Under the conversion of different working conditions, this makes the vibration of different types of cutterheads different. How to choose the appropriate type of cutterhead according to different geological conditions is very important for saving engineering cost and increasing cutterhead life. In view of the above situation, this paper proposes a stability evaluation method during the TBM tunneling process to select the appropriate cutterhead type. Firstly, the corresponding relationship between geology and working conditions is established according to different geological conditions, and the input loads corresponding to geological conditions are obtained. Then, it is substituted into the dynamic model of the cutterhead system, the vibration response boundaries of each degree of freedom are obtained by solving. And the average value of the maximum boundary amplitude of each degree of freedom is taken to represent the extreme vibration of the cutterhead under the corresponding working conditions. Finally, by comparing the fluctuation of the ultimate vibration amplitude of each type of cutterhead in the process of working condition conversion, the results are as follows: when the transition between homogeneous strata and composite strata is normal and there is no large turning and deviation correction, the vibration response of the two-part cutterhead is the smallest, and the two-part cutterhead is the best choice. Otherwise, the five-part cutterhead is the best choice, while the stability of the integrated cutterhead is the worst.

A Prediction Method for TBM Cutterhead Dynamic Tunneling Performance under Typical Composite Geological Conditions

The cutterhead system is a core component of TBM equipment,which works in the extremely severe environment,and the strong impact loads result in severe vibration,crack,damage failure and other engineering failures.Accordingly,the key for cutterhead system structure design and parameter matching is to evaluate and predict cutterhead tunneling per-formance reasonably.In this paper,a prediction method for TBM cutterhead dynamic tunneling performance is pro-posed under the typical composite geological conditions,based on the CSM model of multi-cutters and cutter loads field test data.Then an actual TBM cutterhead of a water conservancy project is taken as an example,a spatial three-dimensional separation zone model for cutterhead tunneling is established under the typical geological condition,and the parameters influence rules of cutterhead tunneling performance are analyzed.The results show that,the cutter-head loads and specific energy change rules with different parameters are basically similar.Moreover,under the condi-tion of penetration p=10mm,the cutterhead bending moment coefficient of variation magnitude exceeds 20%,which is the maximum,and the normal cutter spacing optimal value is 95mm.Also,when the normal cutter spacing is kept constant in 85mm,the penetration has a greater influence on the torque and specific energy coefficient of variations,which is increased from 2mm to 10mm,and the two indexes decrease by about 73%.It is indicated that proper increase of pene-tration is beneficial to reduce the vibration fluctuation degree of torque and specific energy.The proposed method of TBM cutterhead dynamic tunneling performance and the analysis results can provide theoretical basis and design refer-ence for TBM cutterhead layout and tunneling parameters matching.

盾构机换刀机器人抓取机构夹持力建模分析

针对锁钩-销轴式的滚刀抓取机构,基于目前一种适用度较广的间隙接触力模型,考虑接触面摩擦力,建立由滚刀及拆装机构的重力传递至油缸夹持力的数学模型。分析水平工况和竖直工况这2种特殊工况的夹持力模型,进而推导其他工况的抓取机构夹持力模型,并采用ADAMS进行仿真验证。基于换刀机器人试验台开展不同工况下的滚刀夹持状态分析,最后进行对比分析。研究结果表明:夹持力模型计算结果与仿真以及试验结果基本吻合,验证了夹持力模型的正确性,为盾构换刀抓取机构的夹持力输出提供了理论支撑。

复合地层盾构掘进刀盘扭矩波动分析与贯入度预测方法

目的:在复合地层中,盾构掘进时往往会产生较大的刀盘扭矩和扭矩波动,为降低扭矩波动和提高掘进效率,需研究贯入度的预测方法。方法:建立了刀盘滚刀与切刀开挖扭矩模型,并通过考虑复合地层与刀盘的摩擦,建立了复合地层盾构掘进总扭矩模型。在分析复合地层盾构开挖扭矩波动特征的基础上,建立了刀盘扭矩、复合地层组成、贯入度与岩石强度的简化关系,并提出了一种新的预测指标——I MTP(复合扭矩贯入指数)。该指标将扭矩与贯入度结合,可用于评价复合地层开挖面的可切削性。同时提出了一种基于机械性能的贯入度预测方法,其可用于预测不同地质条件和机械性能限制下的贯入度。结果及结论:复合地层盾构掘进总扭矩模型的预测能力可靠性已在南京至句容城际轨道交通工程麒麟镇站—东郊小镇站区间得到了验证。该方法可在复合地层中隧道盾构机械能受限的情况下,将盾构掘进参数与地质条件参数进行匹配,能为隧道掘进施工的安全和效率提供指导与保障。

基于BP神经网络的TBM刀盘关键位置应变重构

为解决恶劣工况下全断面硬岩隧道掘进机(tunnel boring machine,TBM)关键主承力结构应变监测难、监测不准的难题,提出了一种基于BP神经网络和有限元分析的TBM刀盘关键位置应变重构方法.首先,通过静、动力学有限元分析确定了TBM刀盘关键位置,并提取了刀盘典型易损特征子结构.其次,基于有限元技术和实验设计(design of experiments,DOE)方法,分别进行了标准件和特征子结构多载荷下静力学有限元分析,并构建了载荷-应变数据库.最后,运用BP神经网络建立了标准样件和刀盘特征子结构的应变重构模型,并进行了标准样件的实验验证.结果表明,重构应变的平均误差为10%,验证了方法的可行性,为TBM刀盘复杂结构的应变重构提供了一种可行的方法.