西南红层特殊岩土性质与工程应用

目 录

1  西南地区红层分布与工程问题······································································· 1

1.1  红层的基本概念··················································································· 1

1.2  中国红层分布概况················································································ 1

1.3  西南地区红层分布特点·········································································· 3

1.4  西南地区红层典型地层·········································································· 8

1.5  西南地区红层主要工程地质问题··························································· 20

参考文献··································································································· 22

2  红层的组成与结构······················································································ 23

2.1  红层的成因类型·················································································· 23

2.2  西南地区红层的物质组成····································································· 26

2.3  西南红层的岩石结构··········································································· 38

2.4  西南红层岩石的构造··········································································· 41

参考文献··································································································· 46

3  红层岩土工程性质······················································································ 47

3.1  红层的风化························································································ 47

3.2  红层岩土的工程性质··········································································· 55

3.3  红层软岩岩体结构特征········································································ 66

3.4  红层风化松软土工程性质····································································· 74

3.5  红层填料工程性质·············································································· 81

参考文献··································································································· 87

4  红层泥质岩类的崩解··················································································· 89

4.1  红层泥质岩崩解现象与问题································································· 89

4.2  红层泥质岩崩解的试验研究································································· 90

4.3  红层泥质岩开挖崩解过程··································································· 105

4.4  红层泥质岩崩解机理········································································· 106

4.5  红层泥质岩崩解性评价方法································································ 110

4.6  红层泥质岩崩解防治建议··································································· 113

……….

参考文献································································································· 275

10  红层地基工程························································································· 278

10.1  红层地基工程特点········································································· 278

10.2  红层地基岩土工程问题··································································· 278

10.3  红层地基勘察与评价······································································ 283

10.4  红层地基处理················································································ 304

参考文献······························································································· 322

11  红层地下工程························································································· 325

11.1  红层地下工程特征········································································· 325

11.2  红层地下工程特殊岩土问题···························································· 326

前 言

红层是对海陆相沉积的红色地层的统称，在不同的学术研究领域和工程实践中有不尽相同的内涵和外延。本书根据研究背景和服务目的，将红层的定义局限为中生代和第三纪（古、新近纪）在大陆地区湖泊、河流、山麓沉积形成的，以碎屑岩和泥质岩为主要岩石类型的一套地层。这一界定，将其与由岩浆岩、碳酸岩等风化形成的红土层相区别，也不过多涉及中生代以前的红色地层和海相红层。

红层在我国分布较广，其中西南地区是主要红层分布区之一。由于形成环境、区域地质历史演变、内外地质动力条件不同，西南红层工程性质和赋存环境具有典型性和代表性。西南红层从三叠系到白垩系连续形成，在四川盆地和滇中—滇西大面积出露分布，是历时最长、分布最广的裸露红层。受地壳运动的影响，川西南—滇西地区是近以来我国地质作用最为强烈的地区之一，红层中断裂发育、岩体破碎。西南地区年均大气降水一般都在 1 000 mm以上，不少地区高达 1 500～2 000 mm，水对红层岩石的冲蚀、侵蚀作用十分强烈。四川盆地南部和东部的绝对高温和云南的高温差，为西南红层的风化提供了强劲动力。川中盆地内侏罗纪—白垩纪湖泊相泥岩中，蒙脱石、伊利石等亲水矿物含量较高，局部地区常形成民间称为“观音土”的蒙脱石矿层（膨润土）。同时，川渝地区在侏罗纪—白垩纪时期湖面收缩，水中盐分含量升高，以石膏、芒硝为代表的化学沉积成片成层分布。上述特点，使西南红层岩石具有易风化崩解、膨胀、软化、溶蚀、腐蚀等内在的特殊性质。而地震、降雨、地形高差变化、河流沟谷纵横切割等外部条件，使西南地区红层滑坡、崩塌、塌岸等地质灾害频发，给工程建设和人类生产生活造成了极大不便和危害。

我国对红层工程性质的研究，特别是对西南地区红层工程性质研究已逾 50 年。1959年四川水利水电设计院对四川盆地红层岩石风化、软弱夹层、可溶盐、滑坡等特征的研究，开启了红层工程研究的先河。1960—1970 年铁路系统对红层工程性质及红层地质灾害防治措施的大规模研究，是我国红层工程研究的第一次高潮。以成昆铁路红层地区工程建设经验为代表的一大批成果问世。20 世纪 80 年代以后，关于红层的工程研究资料日益丰富，行业、单位、人员大为增加，硕果累累。2003 年，徐瑞春出版了《红层与大坝》一书，这是我国关于红层与工程建设的第一本专著。2000 年后，随着西南地区高速铁路和高速公路的大量修建，以及大规模三峡移民安置中地质灾害防治工程的开展，我国红层岩土工程研究出现了第二次高潮。由于科学技术的发展，这次红层工程研究不论广度、深度还是取得的成果都是前所未有的。

本书作者及其所在单位相关研究人员从 20 世纪 90  年代初期即开始红层岩土工程研究，先后参与云南广（通）—大（理）铁路、京珠高速公路湖南段、遂（宁）—渝（重庆）200 km/h铁路、三峡库区重庆段地质灾害防治技术等红层地区工程建设的研究工作，主持完成多项有关西南红层软岩工程特性及红层工程建设研究课题，从中学习到大量红层岩土特殊性及红层工程问题的相关知识，积累了一批研究资料和成果，同时又困惑于大量尚未解决的问题。因此，本书作者认为，将这些知识、成果、问题集中起来，按知识体系和专业逻辑加以梳理并整理出版，有利于先辈们知识的传承、同行间经验的交流和年轻研究者的探讨与发展。

受限于作者的知识体系、服务对象、研究方向和参与程度，本书内容集中于与工程建设有关的红层岩土的特殊工程性质和铁路与道路红层工程建设问题等方面。按照编写大纲，本书涉及内容分为 3 部分：红层及红层岩土的一般性质、红层岩土的特殊工程性质、红层岩土工程。一般性质部分介绍红层的概念、分布、工程问题、岩性特征和一般工程性质；在特殊性部分主要依据对西南红层的研究，介绍红层岩石的崩解、流变、溶蚀、腐蚀、膨胀等特殊工程性质；红层岩土工程部分介绍红层地下水、边坡、地基、隧道工程问题及处置措施。本书编撰依据的资料，主要源自作者相关研究报告、作者团队的研究生学位论文、作者所在单位其他同事和研究生的论文成果。为保持本书知识体系的完整性，书中还引用了大量国内外相关文献的成果。所有文献、成果均在正文中标注并在各章末列出以示尊重并供参阅。书中涉及的一些术语和惯用语，也按照相关行业习惯使用，不强求统一。

本书是作者团队共同编著的学术著作，作者署名不分先后次序。全书共11章，作者按章序分工编写如下：前言及第9章由谢强编写；第1、4、6、7、8章由郭永春编写；第2、11章由文江泉编写；第3、5、10章由赵文编写。全书由谢强审阅修改。

本书的编写，承蒙中铁二院、中建西勘院等单位提供了大量资料、数据和研究成果，特致谢意。

非常感谢万方副总编对本书出版给予的极大支持。非常感谢责任编辑杨勇、柳堰龙为本书的出版付出的努力和心血。

本书编写过程中，西南交通大学在读博（硕）士生梁树、朱磊等核对了全部文字、公式、图表、数据，荆腾申、赵东升、施金江、范振宇、刘捷、侯旭涛、李青亮绘制了部分插图，特此致谢。

限于作者学识和经验，本书存在的不当甚至谬误，期盼读者批评指正。

本书得到西南交通大学学术专著专项出版基金资助。

作  者

2017年12月