湿陷性黄土地基处理技术在桃同高速公路病害治理中的应用研究

发布时间：2018-06-03 20:15

  本文选题：黄土 + 湿陷性　； 参考：《长安大学》2015年硕士论文

【摘要】：在工程建设和施工的过程中,常常会遇到一些棘手的工程问题,如湿陷性黄土。湿陷性黄土呈现出了高强度的结构模式,在与水相遇时,会极速湿陷、软化。所以,为了保障黄土地区工程建设安全,必须要解决好湿陷性黄土问题。这些年来,随着工程建设的加快,人们也进一步的了解了湿陷性黄土的成因、物理特性、分布形态、强度指标、化学性质、影响因素等情况。当前,在工程建设中,人们治理湿陷性黄土的措施包括:①路基加固法;②排水固结法;③深层密实法;④换填垫层法;⑤化学加固法;⑥置换法;⑦其余方法。在设计和施工环节,会面对多种类别的湿陷性黄土,需要在剖析此段湿陷性黄土的性质之后,再采取针对性的措施,以特殊的处理工艺确保路基质量。本文的研究对象为宁夏桃同高速公路,在分析了其所处区域内的湿陷性黄土的特性之后,结合桃同公路病害现状提出了:(1)以“防排结合、减小湿陷”为目的,通过在路基两侧设置夯实水泥土桩,并恢复全线排水设施,以防地表水通过路基两侧及路基坡面下渗至路基基底;(2)以“挤密加固、提高强度”为目的,通过在路基沉陷严重段落和桥涵台背处设置旋喷桩,以消弱基底黄土的湿陷性和提高路基承载力;(3)以“恢复功能、确保安全”为目的,通过改善路基和桥头差异沉降路段的平整度,并对沿线中央带和路侧护栏进行整治,以确保全线行车舒适性和安全性的公路路基病害处置方案。本项目主要使用湿陷性黄土地基处理技术中的夯实水泥土桩、水泥土隔水墙、高压喷射注浆为主的具体路基沉陷病害处治措施:1)自重湿陷等级为Ⅲ级和Ⅳ级路段:基底进行高压喷射注浆(旋喷桩)处理,桩体应穿透湿陷性黄土层,同时在坡脚处设置φ80cm夯实水泥土桩;(2)自重湿陷等级为Ⅱ级且处于湿陷性等级Ⅲ级和Ⅳ级前后的沉陷较严重路段:坡脚处设置φ80cm夯实水泥土桩;(3)湿陷等级低于自重湿陷Ⅱ级或自重湿陷等级为Ⅱ级但地基已趋于稳定且两侧为旱地的路段:不做处理。(4)其他路段设置2m深、80cm厚的水泥土隔水墙,起隔水作用。在此基础上根据设计方案,提出了湿陷性黄土地基处理技术在宁夏桃同高速公路中的现场实施施工内容:主要包括:夯实水泥土桩、水泥土隔水墙、高压喷射注浆在具体项目施工中的施工工艺、注意事项以及具体的质量控制方案。作者认为这几项处理方法在宁夏地区的其他高速路上湿陷性黄土的处理当中同样适用,但各种湿陷性黄土的处理方法各有其特点及应用范围,在施工中应灵活掌握,需要施工人员在工作中灵活应用,从实际出发,考虑工期要求、环境特性、土层厚度等因素,寻找出一条最合理、经济、快速的处理措施。
[Abstract]:In the process of engineering construction and construction, some difficult engineering problems, such as collapsible loess, are often encountered. Collapsible loess presents a high strength structural pattern. When it meets with water, it collapses and softens. Therefore, in order to ensure the safety of engineering construction in loess area, we must solve the problem of collapsible loess. Over the years, with the acceleration of engineering construction, people also further understand the causes of collapsible loess, physical characteristics, distribution form, strength index, chemical properties, influencing factors and so on. At present, in the engineering construction, the measures for controlling collapsible loess include: 1 subgrade reinforcement method, 2 drainage consolidation method, 3 deep layer compaction method, 4 replacement cushion method, 5 chemical reinforcement method, 6 replacement method and 7 other methods. In the process of design and construction, many kinds of collapsible loess will be faced. After analyzing the nature of collapsible loess in this section, some targeted measures should be taken to ensure the quality of roadbed with special treatment technology. After analyzing the characteristics of collapsible loess in the area of Taotong Expressway in Ningxia, combining with the present condition of the disease of Taodong Highway, this paper puts forward that the purpose of this paper is to "combine prevention and treatment and reduce the collapsibility". By setting up rammed cement soil piles on both sides of the roadbed and restoring the drainage facilities of the whole line, to prevent the surface water from seeping to the subgrade base through both sides of the roadbed and the slope of the subgrade, the purpose of "compaction and reinforcement and improvement of the strength" is taken as the purpose. In order to reduce the collapsibility of loess foundation and improve the bearing capacity of subgrade, the purpose of this paper is to restore function and ensure safety by setting rotary jet pile in serious section of subgrade settlement and at the back of bridge and culvert abutment, so as to reduce collapsibility of loess base and improve bearing capacity of roadbed. By improving the smoothness of the subgrade and bridge head differential settlement section and renovating the central belt and side guardrail along the road to ensure the comfort and safety of the whole road roadbed disease disposal scheme. This project mainly uses the rammed cement-soil pile in the collapsible loess foundation treatment technology, the cement soil water barrier wall, Treatment measures of concrete roadbed subsidence Diseases mainly by High pressure Jet grouting; the grade of deadweight collapsibility is grade 鈪，

本文编号：1974038