The Application Research On Subgrade Filled With Coal Gangue

Coal gangue is the waste during the coal mine construction, coal mining and processing, is a mixture of the variety of soft rock components, 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 safety.It 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:①The physical and chemical composition, weathering and spontaneous combustion characteristics of coal gangue in the bajiaowan. Results show that the burned coal gangue and unburned coal gangue have not obviously suitable chemical composition for subgrade compaction. The burned coal gangue is used as subgrade filling better than unburned coal gangue.②The basic physical properties of coal gangue in the bajiaowan. Through the laboratory tests, apparent density, crumbling quantity and crush value of burned coal gangue and unburned coal gangue have been analyzed. The result shows that compared with unburned coal gangue, burned coal gangue has several characteristics: easy differentiation, easy disintegration, and low crush value so on.③Test stabilized gangue subgrade mixture compaction characteristic and CBR value. Through the compaction test and Califonia Bearing Ratio test, it concludes that the bearing capacity of burned coal gangue and unburned coal gangue mixture can both satisfy the freeway roadbed requirements. ④Inorganic binding material stability gangue subgrade mixture properties research. Through the unconfined compressive strength test and shrinkage test of the stabilized gangue, it can draw that cement stabilizes significantly unburned coal gangue and lime and fly-ash stabilizes significantly obviously burned coal gangue.⑤Stable gangue subgrade mixture settlement analysis. FLAC software is applied to simulate stability burned coal gangue subgrade and clay subgrade (control). It is concluded that the horizontal displacement and vertical settlement of stability burned coal gangue subgrade and clay subgrade has much fewer, it can clearly be seen stability burned coal gangue mixture of the subgrade compactness is feasible.