EXPERIMENTAL RESEARCH ON INFLUENCES OF PHYSICAL INDICES AND MICROSTRUCTURE PARAMETERS ON STRENGTH PROPERTIES OF RED STONE FROM WESTERN HUNAN
LIN Zhihong1，XIANG Wei1，ZHANG Yunming2
(1. Faculty of Engineering，China University of Geosciences，Wuhan，Hubei 430074，China；2. China Railway Siyuan Survey and Design Group Co.，Ltd.，Wuhan，Hubei 430063，China)
Abstract：Some experiments are conducted including measuring basic physical indices and uniaxial compressive strength(UCS)，mineral composition，grain area ratio(GAR)，packing density(PD)，and grain contact(GC) of cretaceous red sandstone from Western Hunan by physico-mechanics tests through polarized microscope analysis，and powder X-ray diffraction analysis. The average grain diameter and cumulative relative curve of red sandstone are obtained by the grain size analysis. In order to analyze the wetting soften mechanism of sandstone，the uniaxial compressive tests of different red sandstone samples are conducted under the dry state，the nature state and the saturation state. Additionally，how the basic physical indices and microstructure parameters impact the UCS and strength reduction(SR) due to wetting is investigated. Experimental results indicate that the UCS shows a negative exponential relationship with porosity and saturated water adsorption，but a positive exponential relationship with dry density，and a positive linear relationship with GAR，PD，and GC. However，the average grain diameter has no obvious influence on the UCS of red sandstone. When the clay content is higher than 25%，the UCS and SR decrease with the increase of the clay content. Among multifactorial regression analysis，the GAR and saturated water absorption are found to be the key parameters. As a result，the regression equations of UCS and SR due to wetting，in terms of GAR and saturated water absorption，are proposed.
收稿日期: 2009-05-11
引用本文:
林志红，项伟，张云明. 湘西红砂岩基本物理指标和微结构参数对其强度影响的试验研究[J]. 岩石力学与工程学报, 2010, 29(01): 124-133.
LIN Zhihong1，XIANG Wei1，ZHANG Yunming2. EXPERIMENTAL RESEARCH ON INFLUENCES OF PHYSICAL INDICES AND MICROSTRUCTURE PARAMETERS ON STRENGTH PROPERTIES OF RED STONE FROM WESTERN HUNAN. , 2010, 29(01): 124-133.
