雷州半岛玄武岩残积土的工程地质特性研究

  本文关键词：雷州半岛玄武岩残积土的工程地质特性研究，由笔耕文化传播整理发布。

第36卷 第5期 岩 土 工 程 学 报 Vol.36 No.5 2014年5月 Chinese Journal of Geotechnical Engineering May 2014 DOI：10.11779/CJGE201405007

雷州半岛玄武岩残积土的工程地质特性研究

张先伟1，2，孔令伟，臧 濛 11

（1. 中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室，湖北 武汉 430071；2. 同济大学岩土及地下工程教育部重点实验室，上海 200092）

摘 要：雷州半岛玄武岩残积土属于区域性特殊土，全面系统地评价玄武岩残积土的工程地质特性对于该地区建设、

地质工程勘察具有重要指导意义。玄武岩残积土是由玄武岩经过长期缓慢的风化分解与红土化作用形成，土层分布具

有上细下粗的结构特征。黏土矿物以高岭石类为主，含有较多的游离氧化铁、铝。微观结构以凝块和絮凝结构为主，

粒径小于1 μm的微孔占总孔隙70%以上。特殊的物质构成与结构形态导致其具有高孔隙率、低密度、高液限的物理特

性，但强度较高的力学特征。该土的膨胀性小，但收缩性较大，夯击压实效果差，抗水性差，浸水饱和后力学性质劣

化明显，同时对温度与湿度等环境因素敏感，在炎热多雨的气候影响下，颗粒间胶质容易发生脱水老化，导致结构强

度减损，微观尺度上结构扰动、破坏，遇水产生严重的崩解现象与较大的湿陷变形，实际工程应关注强收缩势与降雨

积水引发的工程灾害。

关键词：雷州半岛；玄武岩残积土；工程特性；微观结构；矿物成分

中图分类号：TU446 文献标识码：A 文章编号：1000–4548(2014)05–0855–09

作者简介：张先伟 (1982– )，男，，黑龙江省龙江人，博士，助理研究员，从事特殊土的力学特性研究。E-mail: xwzhang@ 。

Engineering geological characteristics of basalt residual soils in Leizhou Peninsula

ZHANG Xian-wei1, 2, KONG Ling-wei1, ZANG Meng1

(1. State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of

Sciences, Wuhan 430071, China; 2. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji

University, Shanghai 200092, China)

Abstract: The basalt residual soil in Leizhou Peninsula is special regional soil. Comprehensive and systematic evaluation of engineering geological characteristics of the basalt residual soil can provide a certain theoretical support for its engineering investigation and construction. It is formed from the basalt by a long period of weathering and laterization, and the soil particles in the upper layer are smaller than those in the lower layer. Its clay mineral is mainly kaolin, furthermore, it contains more free iron oxide and free aluminium oxide. Its microstructure is mainly clot and flocculation structure, and the pores with a size of greater than 1 μm are more than 70% of the total porosity. The basalt residual soil has poor physical properties of high porosity, low density, high liquid limit and possesses better mechanical properties of high strength because of special composition and microstructure. The basalt residual soil has small expansibility, great shrinkage, insignificant tamping compatibility, and poor water resistance, and its mechanical properties are deteriorated significantly after immersion in water. And the basalt residual soil is more sensitive to the environmental factors such as temperature and humidity. The cementing materials of skeleton will dehydrate and exhibit aging in hot and wet climate, and thus their structural strength is weakened and microstructure is disturbed and damaged. The soils after immersion show serious disintegration and large collapsible deformation. Therefore, geotechnical engineers should pay close attention to engineering disasters due to strong shrinkage and meteoric water.

Key words: Leizhou Peninsula; basalt residual soil; engineering characteristic; microstructure; mineral composition

0 引 言

中国的雷州半岛及海南岛北部广泛分布着第四系

喷发的玄武岩（图1），雷州半岛玄武岩发育在喜马拉

雅构造运动雷琼断陷中，形成时期可划分为早晚两期，

早期为中更新世（石峁岭组Q2s）；晚期为晚更新世（湖光岩组Q3h）[1]。该区气候属温暖潮湿，干湿季节变化明显的热带季风气候，这为玄武岩快速风化分解及红─────── 基金项目：湖北省自然科学基金项目（2011CDB406）；岩土及地下工程教育部重点实验室（同济大学）开放课题（KLE-TJGE-B1103）

收稿日期：2013–09–23

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  本文关键词：雷州半岛玄武岩残积土的工程地质特性研究，由笔耕文化传播整理发布。