Formation Mechanism and Engineering Characteristics of Sandy Dolomite in Wuhan Tianxingzhou Carbonate Rock Belt
Mo Yun
Hu Xinli
Cui Deshan
Xie Zhaoyu
Jin Xinfeng
Xiong Zonghai
Abstract：The Tianxingzhou carbonate rock belt in Wuhan has developed an exceptionally thick sandstone dolomite formation.To elucidate the genesis and engineering characteristics of this rock formation,a comprehensive study was undertaken employing various methods,including structural surveys,thin section analysis,X-ray diffraction(XRD),X-ray fluorescence(XRF),particle analysis,and saturated uniaxial compressive strength tests.The results indicate that the study area is situated between three faults,and the strata are inverted,suggesting that the region experienced intense compressive stress during the Indosinian period and tensile stress during the Yanshan period.Regional structural features and microscopic observations corroborate this interpretation.Notably,the higher the degree of sandstone,the lower the dolomite mineral content,and the higher the quartz and clay mineral content.The migration and evolution characteristics of major chemical components,such as CaO and MgO,exhibit a negative correlation with the dolomite sandstone process,while components like SiO2,Al2O3 and Fe2O3 display a positive correlation.In summary,the primary causes of the dolomite sandstone and its heterogeneous characteristics in the study area can be attributed to three distinct scales:"macroscopic structural dynamics","microscopic mineral structure composition",and"microscopic chemical composition evolution".The degree of sandstone significantly influences the saturated uniaxialcompressive strength of dolomite.The reduction amplitudes for the"micro-weak","micro-medium",and"micro-strong"sandstone stages can reach 38.6%,68.1%,and 90.0%,respectively,exhibiting a power function relationship.Consequently,the standard value of the saturated uniaxial compressive strength for the fully sandstone and extremely broken dolomite in ⑤1 layer was fitted to be 1.3 MPa,resolving the engineering challenge of obtaining rock mechanics parameters for fully sandstone dolomite through indoor testing of standard rock samples.
Keywords：Wuhan Tianxingzhou carbonate rock beltsandy dolomiteformation mechanismengineering propertiesengineering geology
Publication Date：2025-06-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：13( 2298-2310 )