复合地层超大直径盾构刀盘刀具维护数字化决策支持研究

王晨雯

摘 要

随着城市的发展，人类的人居、商业与交通出行逐渐向地下空间延伸。在地下工程施工中，盾构工法因环境影响较小、安全性较高等优势而被广泛采用。近几年，人类的地下空间开发力度快速加大，大直径盾构隧道的建设需求越来越多。大直径盾构的开挖大断面，也导致遭遇多地层复杂地质的工况成为常态，带来了如刀盘刀具维护困难、掘进失稳风险增大及超大管片拼装低效等一系列工程挑战。其中，超大直径盾构（刀盘外径超过14米）特别是穿江越海重要通道、城区快速地下道路，常常在上软下硬的高磨蚀性复合地层中掘进施工，其埋深更深、环境更复杂、刀盘刀具磨损等问题尤为突出，如何高效地对在役刀盘刀具进行评估检测，如何合理地平衡换刀频率与工程掘进效率成本的关系，如何有效地分析盾构掘进参数海量数据而对刀盘维护与换刀决策进行支持，亟待进一步深入研究。

鉴于此，通过研究超大直径盾构施工的跨尺度建模，基于跨尺度BIM模型的数字化管控系统框架设计，以及盾构施工的数字化决策支持等内容，本文提出了一整套用于盾构隧道施工的数字化管控流程方法，并以在役刀盘刀具磨损量预测和换刀决策为例，进行了重点分析，主要包含了以下研究工作：

1、提出跨尺度BIM建模概念，并以某市某超大直径盾构隧道工程为例建模。跨尺度BIM建模超出了传统中观尺度的隧道本体结构建模，还包括宏观尺度的周边环境建模、工程与水文地质空间建模，细观尺度的核心施工装备（如：盾构机）建模。

2、提出基于跨尺度BIM的数字化管控系统框架，集数据管理、分析和施工决策功能于一体，系统包括盾构在役刀盘动态维护子系统，能支持刀具数据的录入、查看、统计和导出。为了加强数据管理功能，基于VBA语言（Visual Basic for Applications，用于扩展Windows应用程序功能的通用自动化语言）开发人工采集刀具数据的信息录入界面，形成两种不同详细程度的结构化存储形式。

3、在基于跨尺度BIM的数字化管控系统的支持下，完成五项施工试点应用，其中重点介绍基于XGBoost算法的复合地层盾构刀具磨损预测和增加考虑工程掘进效率的换刀决策分析。前者基于详细结构化存储形式的刀具数据、盾构和地质参数数据，完成刀具消耗分析、磨损系数分析和基于XGBoost算法的磨损预测。后者基于简略结构化存储形式的刀具数据、盾构和地质参数数据，定义以单刀产量为系数的刀盘磨损度指标，构建贯入度与刀盘磨损度、总挤压力、刀盘扭矩、刀盘转速的数学模型，阐明综合成本与两类换刀策略，在AnyLogic软件中用系统动力学和离散事件分别建立盾构刀具磨损和盾构施工过程仿真模型，结合计算贯入度的数学模型，综合刀具使用寿命和工程掘进效率分析换刀决策。

基于跨尺度BIM的数字化管控系统能更好地满足工程实际需求并提供有效的施工指导，对保障复合地层超大直径盾构工程施工的安全和成功，以及节省工程成本和工期有重大意义。同时，也为打通地下结构施工期与运维期的全生命周期数据共享，提供了实施路径与方法框架。

关键词：盾构隧道；复合地层；数字化管控；刀盘磨损；换刀决策

ABSTRACT

With the development of the city, human habitation, commerce and transportation gradually extend to the underground space. Shield method is widely used in underground engineering because of its advantages of less environmental impact and higher safety. In recent years, the development of human underground space has been increasing rapidly, and the demand of large-diameter shield tunnels construction has been increasing. The excavation of large section of large-diameter shield tunneling also leads to the normal condition of encountering complex geological conditions of multiple strata, which brings a series of engineering challenges such as difficult maintenance of cutterhead and cutting tools, increased risk of instability in tunneling and low efficiency of assembling super-large segments. Among them, the super-large diameter shield (more than 14 m in diameter), especially the important channel in the sea, the city underground fast-driving road, often under the soft hard tunneling construction in highly abrasive composite strata, the buried depth deeper, environment more complex, the cutterhead and cutting tool wear problem is particularly prominent. How to evaluate and detect the in-service cutterhead and cutting tool efficiently, how to reasonably balance the relationship between the cutting tool replacement frequency and the engineering tunneling efficiency cost, and how to effectively analyze the mass data of the shield tunneling parameters and support the maintenance of the cutterhead and the decision of cutting tool replacement, it is urgently needed to be further studied.

In view of this, by studying the cross-scale modeling of super-large diameter shield construction, the framework design of digital management and control system based on cross-scale BIM model, the digital decision support for shield construction and so on, this paper proposes a set of digital control process for shield tunnel construction, and takes cutterhead and cutting tool wear prediction and cutting tool replacement decision as examples to carry on the selective analysis. It mainly includes the following studies:

1. Put forward the concept of cross-scale BIM modeling, and took a super-large diameter shield tunnel project of a city as an example for modeling. The cross-scale BIM modeling goes beyond the traditional meso-scale modeling of the tunnel body structure, and also includes the macro-scale modeling of the surrounding environment and the geological space modeling, and the meso-scale modeling of the core construction equipment (eg: shield tunneling machine).

2. Put forward a digital management and control system framework based on cross-scale BIM, which integrates data management, analysis and construction decision-making functions. The system includes dynamic maintenance subsystem of in-service cutterhead of shield construction, which can support the input, view, statistics and export of cutting tools data. In order to strengthen the function of data management, based on VBA language (Visual Basic for Applications, a general automation language used to extend the function of Windows Applications), the information entry interface of manual cutting tool data collection is developed to form two structured storage forms with different levels of detail.

3. With the support of the digital management and control system based on the cross-scale BIM, five construction pilot applications were completed, in which the prediction of cutting tool wear in shield tunneling and the decision analysis of cutting tool replacement further considering the tunneling efficiency of the project were mainly introduced. The former is based on cutting tool data in the form of detailed structured storage, shield and geological parameter data to complete cutting tool consumption analysis, wear coefficient analysis and wear prediction based on XGBoost algorithm. The latter is based on cutting tool data in the form of brief structured storage, shield and geological parameter data to define a cutterhead wear index with weight coefficient of single cutting tool yield and build the mathematical model of penetration and cutterhead wear, total extrusion, torque and rotational speed. The comprehensive cost and two kinds of cutting tool replacement strategies were illustrated. The simulation models of cutting tool wear and shield tunneling process were established by using system dynamics and discrete events in the software AnyLogic, and the cutting tool replacement decision was analyzed by combining with the mathematical model used to calculate penetration, cutting tool life and tunneling efficiency.

The digital management and control system based on cross-scale BIM can better meet the actual needs of the project and provide effective construction guidance, which is of great significance to ensure the safety and success of the super-large diameter shield tunneling project in composite strata, and to save the project cost and time limit. At the same time, it also provides the implementation path and method framework for the whole life cycle data sharing of the underground structure during construction and operation.

Keywords: Shield Tunnel; Composite Strata; Digital Control; Cutterhead Wear; Cutting Tool Replacement Decision