煤矸石填筑路基的应用研究.doc

摘要
煤矸石是在煤矿建设、煤炭开采及加工过程中排放出的废弃物,是一种多种软岩成分的混合体,属于“软质粗粒土”。如今大量堆积的煤矸石不仅占用大量耕地、林地、居民地,而且污染大气、农田和水体,甚至危及人身安全,对社会和环境造成很大的影响。
目前,重庆在建一条万盛至南川的高速公路,由于无法绕避,途径南桐矿区芭蕉湾的煤矸石山。从节约成本和因地制宜的角度出发,将积存已久的煤矸石作为在建公路的路基填料,具有一定的经济环境效益。然而目前路基规范中并没有相应的指标和标准规范煤矸石的应用。本文以重庆市南桐芭蕉湾煤矸石山的已燃和未燃煤矸石为主要研究对象,进行了大量的室内试验,对其路用性能展开了研究。主要研究成果如下:
①芭蕉湾煤矸石的物理化学组成、风化和自燃特性研究。结果表明已燃和未燃煤矸石中都没有明显不适于路基填筑的化学成分,已燃煤矸石作为路基填料优于未燃煤矸石。
②芭蕉湾煤矸石的基本物理性质研究。通过室内试验,对已燃和未燃煤矸石的表观密度、崩解量、压碎值等进行分析,结果表明相对于未燃煤矸石,已燃煤矸石具有易分化、易崩解、压碎值低等特点。
③测试稳定煤矸石路基混合料的击实特性及CBR值。通过击实试验和承载比试验研究得出已燃和未燃煤矸石混合料的承载力均能满足高速公路路基要求。
④无机结合料稳定煤矸石路基混合料性能研究。通过稳定煤矸石的无侧限抗压强度试验和收缩试验,得出水泥稳定未燃煤矸石作用显著,二灰稳定已燃煤矸石效果明显。
⑤稳定煤矸石路基混合料沉降分析。应用FLAC软件对稳定已燃煤矸石路基和粘土路基(对照)进行模拟,得出稳定已燃煤矸石路基和粘土路基水平位移和竖向沉降相差不大,可见稳定已燃煤矸石混合料的路基方案是可行的。
关键词:已燃煤矸石;未燃煤矸石;路基填筑;无侧限抗压;收缩;数值模拟
ABSTRACT
Coal gangue is the waste during the coal mine construction, coal mining and processing, is a mixture of the variety of soft ponents, belong to "soft coarse- grained soil". Now lots of accumulations of coal gangue could not only occupy the cultivated lands, woodlands, residential lands, but also pollute the atmosphere, farmlands and water, and even endanger the personal has made a significant contribution to natural and social environment It causes a great influence of social and environment.
At present, a freeway wansheng to nanchuan under construction in chongqing, unable to avoid, way around the mountain of NanTong mining coal gangue. From the saving cost and the local conditions of view, will accrue already a long time of gangue as subgrade filling construction of freeway, have a certain economic and environmental benefits. However, there is no corresponding indicators and standard to guide the gangue application in the current standard of roadbed. This paper takes the burned coal gangue and unburned coal gangue in chongqing NaTong bajiaowan gangue mountain as the main research object, having a lot of indoor test, and carry out their road performance studies. The main research results are as follows