土压平衡盾构排土系统的分析与设计

发布时间：2018-01-16 08:15

本文关键词：土压平衡盾构排土系统的分析与设计　出处：《湖南大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来，随着我国城市建设的迅速发展，城市地下各种隧道的开挖利用成为解决建设用地紧张的有效途径。盾构施工法作为一种安全高效的隧道挖掘技术得到了广泛的应用，其中土压平衡盾构又以其技术及经济上的优越性，成为地下隧道施工技术的主流。但是由于施工地层地质条件的复杂性等因素的影响，在实际施工过程中经常会遇到各种因排土问题导致的施工故障，具有代表性的有结饼、闭塞、喷涌及开挖面失稳等，这些施工故障严重阻碍了施工进程甚至造成安全事故。目前，对上述施工故障的应对措施多是依靠对开挖土体的改良，而在改良剂的选择与使用方面多是依靠经验反复的摸索试验，存在着盲目性，同时，对影响土体改良效果至关重要的搅拌机构的研究甚少。此外，对螺旋输送机结构的合理设计，满足防喷涌的功能要求，及保证其较强的排土能力都有助于上述施工故障的解决。本文针对上述情况，进行了以下研究工作： (1)分析四种常见故障的发生机理，针对排土系统中存在的问题，从土体改良、搅拌机构、螺旋输送机三个方面提出相应的改进措施。 (2)鉴于国内目前气泡剂技术在辅助土压平衡盾构施工中存在的一些问题，在阐述土仓土体形态及其力学特性的基础上，结合土压平衡盾构施工的原理，分析土仓土体的性质要求，从气泡剂自身性质和气泡改良土性质两方面阐述气泡剂在土压平衡盾构施工中应用效果的评价手段及相应的指标，为气泡剂技术在土压平衡盾构中的选择和使用提供实际参考。 (3)针对土压平衡盾构机搅拌棒、搅拌叶片进行设计，完成方案设计。基于阿基米德螺旋线的特性提出了一种基于阿基米德螺旋线的搅拌棒的布置方法。分析了理想状态和实际工作状态下搅拌叶片的工作情况，，为保证土体轴向和横向同时有较大的运动，对搅拌叶片的安装角进行分析，得出叶片安装角的理想值。 (4)针对盾构螺旋输送机功能要求，设计具有防喷涌功能的可伸缩式螺旋输送机，并完成详细的结构设计和接口设计及液压系统设计。根据盾构螺旋输送机工作特点，用遗传优化算法建立了参数化的螺旋体的优化数学模型，建立了考虑螺旋片断开情况的目标优化模型，并得到了较好的优化结果。
[Abstract]:In recent years , with the rapid development of urban construction in China , the excavation and utilization of various tunnels in the city has become an effective way to solve the tension of construction land . In the light of the above , the following studies have been conducted : ( 1 ) The mechanism of four common faults is analyzed , aiming at the problems existing in the soil discharging system , the corresponding improvement measures are put forward from three aspects of soil improvement , mixing mechanism and screw conveyor . ( 2 ) In view of some problems existing in the construction of auxiliary earth pressure balance shield by the present technology of gas bubble agent in China , the paper expounds the soil structure and its mechanical properties , combines the principle of soil pressure balance shield construction , analyzes the property requirements of soil mass , and expounds the evaluation method and corresponding index of the application effect of the bubble agent in soil pressure balance shield construction from two aspects of the property of the bubble agent and the soil properties , and provides practical reference for the selection and use of the bubble agent technology in the soil pressure balance shield . ( 3 ) According to the design of mixing rod and stirring blade of soil - pressure balance shield machine , a kind of stirring bar arrangement method based on the spiral of archimedean is put forward . Based on the characteristics of the spiral line of archimedean , an arrangement method of stirring bar based on archimedean helix is put forward . The ideal condition and the working condition of the stirring blade in the actual working state are analyzed . In order to guarantee the axial and transverse movement of the soil body , the installation angle of the stirring blade is analyzed , and the ideal value of the blade mounting angle is obtained . ( 4 ) According to the functional requirements of shield spiral conveyor , a retractable screw conveyor with anti - surge function is designed , and detailed structural design and interface design and hydraulic system design are completed . According to the working characteristics of shield spiral conveyor , the optimization mathematical model of parameterized helix is established by genetic optimization algorithm , and the objective optimization model considering the opening of spiral segments is established , and the better results are obtained .

【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.39

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