适用于复合地层的硬岩泥水平衡顶管关键技术

为了提高国产顶管对硬岩复合地层等复杂地质条件的适应性和设计制造水平，结合南宁市邕宁区污水管道工程，对适用于复合地层的硬岩泥水平衡顶管关键技术进行探究。其关键技术包括： 研究适用于复合地层的紧凑型刀盘结构，优化刀具组合形式；基于常用的岩石破碎方法，设计一种变位剪切二次破碎机构； 通过刀盘偏心超挖、设置石粉导流槽、盾体注入黏土的方法，解决硬岩地层中易卡盾体、卡管节的难题；完成“泥水舱+气垫舱”的双舱设计，采用泥水压力快速精准测量、阀门模块化自动控制，实现地层的低扰动掘进； 进行带压换刀和常压换刀的针对性设计，实现狭小空间快捷安全换刀；结合泥水循环系统多种模式的转变和自冲洗、高压水冲洗位置的合理布置，提出泥水循环系统防堵塞措施。研制出的适用于复合地层的硬岩泥水平衡顶管在工程施工过程中掘进性能良好，地质适应性强。

Key Technologies of Hard Rock Slurry Balance Pipe Jacking Machine for Composite Ground

In order to improve the manufacturing level and feasibility of home made pipe jacking machine to composite strata, the key technologies of hard rock slurry balance pipe jacking machine for composite ground are studied by taking the sewage project at Yongning District, Nanning for example. The research content includes: (1) A compact cutterhead structure suitable for the composite ground is studied, and the combination form of cutters is optimized. (2) Based on the commonly used rock breaking method, a kind of variable position shear secondary crushing mechanism is designed. (3) By means of eccentric overbreak of cutterhead, setting stone powder diversion channel and injecting clay into the outer side of the shield, the problem of easy jamming of shield and pipe in hard rock stratum is solved. (4) The double structure of "slurry chamber + air cushion chamber" is designed; and through the rapid and accurate measurement of mud water pressure and the modular automatic control of valves, the low disturbance driving is realized. (5) The targeted design of cutter replacement under pressured condition and atmospheric condition is carried out to realize safe cutter replacement in a narrow space. (6) The anti blocking measures for mud water circulation system are proposed by combining with the transformation of various modes of mud water circulation system and the rational arrangement of self flushing and high pressure water flushing positions. The developed hard rock slurry balance pipe jacking machine for composite ground has a good performance and strong geological adaptability in the practice.