基于CPTU原位测试的土-膨润土隔离墙的物理力学性质评价

论文总字数：30016字

摘 要

土-膨润土是一种很好的垂直防渗墙体材料，目前已被很多欧美国家广泛的应用于生活垃圾填埋场的的垂直防渗系统当中。土-膨润土隔离墙具有渗透性能低、施工简单、成本低廉、可有控制地下污染等众多优势。但是国内对于土-膨润土隔离墙的研究和应用还比较少。特别是对土-膨润土隔离墙的物理力学性质的评价相关的研究更是缺乏。

孔压静力触探（CPTU）技术自20世纪80年代被研制成功后，在欧美国家发展非常迅速，已经应用于很多的工程中。孔压静力触探（CPTU）技术具备了快捷、连续、可靠、参数多等诸多特点，因此其应用在土-膨润土竖向隔离墙的物理力学性质评价上，尤其是对该隔离墙固结渗透特性的评价时，具有很大的优势。可以很好地弥补室内试验中操作繁琐，耗时较多，试验结果易出现偏离等缺陷。

本文以江苏省靖江市某生活垃圾填埋场土-膨润土竖向隔离墙为工程实例，以土-膨润土的物理力学特性为主要研究对象，采用了CPTU原位试验与室内试验相结合的研究方法，初步探索了CPTU的基本原理，深入研究了基于CPTU原位试验评价土-膨润土竖向隔离墙隔离效果的方法。全文主要研究内容如下：

1. 介绍了孔压静力触探（CPTU）技术的基本原理和发展现状，并解释了利用孔压静力触探（CPTU）技术确定土-膨润土隔离墙物理力学参数的方法。
2. 深入分析了基于CPTU孔压消散试验确定土-膨润土隔离墙固结系数和渗透系数的方法,进而完成了对土-膨润土隔离墙隔离效果的评价。研究表明，该隔离墙渗透系数小于1x10^-7cm²/s，达到相关标准要求，隔离效果良好。
3. 通过室内试验测试5%膨润土掺量的土体试样固结系数，并利用经验公式求出试样土体的渗透系数。进而对该隔离材料的隔离效果进行评价。试验结果表明，此隔离材料的隔离效果良好，与CPTU原位测试结果具有一致性。

关键词：孔压静力触探（CPTU）；土-膨润土；隔离墙；隔离效果；渗透系数

Abstract

Soil-bentonite mixture (SBM) is one of the materials with a hydraulic conductivity low enough to be used as a containment barrier for contaminated soil, which has been widely applied in landfills vertical cut-off walls systems by many European and American countries. Soil-bentonite cut-off walls have many advantages, such as low hydraulic conductivity, simple construction, low cost, can control the underground pollution effectively. However, there is limited research and application about Soil-bentonite mixture (SBM).Especially the research about evaluation of physical and mechanical properties of the Soil-bentonite cut-off walls.

Since the piezocone penetration test (CPTU) was invented in 1980s,it has been developed rapidly in European and American countries. CPTU has many advantages, such as fast, continuous, reliable and multi-parameter. Hence, CPTU has a great advantage in evaluation of physical and mechanical properties of the Soil-bentonite cut-off walls, especially the consolidation and permeability characteristics.

This paper will rely on an example of landfill Soil-bentonite cut-off walls in Jingjiang City, Jiangsu Province. The physical and mechanical properties of Soil-bentonite cut-off walls are the main research objects. The research method of combining CPTU in-situ test and laboratory test will be adopted. The basic principle of CPTU will be preliminarily explored. And the method of evaluating the effect of Soil-bentonite cut-off walls will be studied based on CPTU in situ test. The main research contents and results are summarized as follows:

(1)Introduce the basic principle and development of CPTU, and explain how to use CPTU to determine the physical mechanics of Soil-bentonite cut-off walls technology parameters.

(2)The method of determining the consolidation coefficient and permeability coefficient of the Soil-bentonite cut-off based on the CPTU is analyzed in depth, and then completed the evaluation of the effect of the And then completed the evaluation of the effect of the soil bentonite isolation wall. Research shows, the permeability coefficient of the Soil-bentonite cut-off is less than 1x10-7cm2/s, which meets the requirements of the relevant standards.

(3)Through the laboratory test of coefficient of consolidation of 5% bentonite - soil sample, and the empirical formula to calculate the permeability coefficient of soil sample. And on the insulating material isolation effect was evaluated. The experimental results show that this isolation material’s isolation effect is good. CPTU in-situ test results and laboratory test results have consistency.

Keywords: Piezocone Penetration Test (CPTU); soil-bentonite; cut-off walls; effect evaluation; permeability coefficient

目录

摘要 2

Abstract 3

第一章 绪论 6

1.1引言 6

1.2国内外研究现状 7

1.2.1现代多功能CPTU发展现状 7

1.2.2土-膨润土竖向隔离墙研究现状 8

第二章 基于高精度CPTU的物理力学参数确定方法 10

2.1高精度CPTU技术研究现状 10

2.1.1CPTU技术的基本原理 10

2.1.2国内外基于CPTU的参数确定现状及对比 13

2.2基于CPTU测试的土性参数的确定方法 15

2.2.1状态特性参数 15

2.2.2强度特性参数 16

2.2.3变形特性参数 17

2.3试验结果分析 18

2.3.1土层重度 18

2.3.2 超固结比OCR 19

2.3.3土的不排水抗剪强度Su 20

2.3.4土的压缩模量Es 21

2.4本章小结 22

第三章 基于高精度CPTU的土-膨润土隔离墙隔离效果评价 23

3.1 实验概况 23

3.1.1实验装置 23

3.1.2操作方法 23

3.1.3试验详情 23

3.2 试验结果 23

3.2.1 标准消散曲线 23

3.2.2 渗透特性评价 24

第四章 基于室内试验土-膨润土隔离墙固结渗透特性研究 26

4.1概述 27

4.2试验过程 27

4.2.1试验材料 27

4.2.2试样制备 27

4.2.3试验方案 28

4.3试验结果和分析 28

4.3.1固结系数 28

4.3.2渗特性评价 29

4.4本章小结 30

第五章 总结与展望 31

5.1总结 31

5.2不足与展望 31

参考文献 32

致谢 35

第一章 绪论

1.1引言

剩余内容已隐藏，请支付后下载全文，论文总字数：30016字