南京秦淮东河黄马青组砂岩工程地质性质研究
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摘要
调查和试验发现,南京秦淮东河沿线黄马青组砂岩对新开河道高边坡的稳定性起到关键作用。XRD试验表明,岩石中粘土矿物含量较高,岩石软化性强,吸水后微裂隙逐渐扩展、贯通,导致岩石易发生开裂。根据抗压试验确定该类岩石属于软岩范畴,风化加剧岩石软化性。根据波速确定岩体完整性指数小于根据体积节理数确定完整性指数值。水对岩石的力学性质影响显著,未来河道边坡开挖后应特别关注水对岩石风化和边坡稳定性的影响。
Field reconnaissance and engineering test results indicate that the properties of Qinghuai East River sandstone of Huangmaqing Formation(T2 h) are critical to the stability of the proposed high cut rock slopes. The X-ray Diffraction(XRD) tests indicates that high clay mineral contents exist in sandstone so that the rock will likely be softened when absorbing the water. Rock mass fractures could also be developed after the water infiltrating and connecting the microcracks. The targeted sandstone was categorized as soft rock by the unconfined compressive strength tests on intact rock samples. When exposed in the ambient atmosphere, the soft rock will be softened. The evaluation results indicate that the rock mass integrity index determined from the shear wave velocity is less than that of determined from the volumetric joint methods. It is also concluded that the water is a critical factor affecting the rock mass properties and the stability issue of the proposed slope excavation should pay attention to the effect of water.
Field reconnaissance and engineering test results indicate that the properties of Qinghuai East River sandstone of Huangmaqing Formation(T2 h) are critical to the stability of the proposed high cut rock slopes. The X-ray Diffraction(XRD) tests indicates that high clay mineral contents exist in sandstone so that the rock will likely be softened when absorbing the water. Rock mass fractures could also be developed after the water infiltrating and connecting the microcracks. The targeted sandstone was categorized as soft rock by the unconfined compressive strength tests on intact rock samples. When exposed in the ambient atmosphere, the soft rock will be softened. The evaluation results indicate that the rock mass integrity index determined from the shear wave velocity is less than that of determined from the volumetric joint methods. It is also concluded that the water is a critical factor affecting the rock mass properties and the stability issue of the proposed slope excavation should pay attention to the effect of water.
引文
[1] 殷跃平,胡瑞林.三峡库区巴东组(T2b)紫红色泥岩工程地质特征研究[J].工程地质学报,2004,12(2):124-135.
[2] 张莉萍,许宝田,邱德俊,等.南京秦淮东河黄马青组(T2h)砂岩水致劣化特征分析[J].工程地质学报,2018,26(2):391-399.
[3] XU BT, YAN C H, XU S. Analysis of the bedding landslide due to the presence of the weak intercalated layer in the limestone[J]. Environmental Earth Sciences, 2013(70):2817-2825.
[4] 中华人民共和国国家标准.工程岩体分级标准(GB/T 50218—2014)[S].北京:中国计划出版社,2014.
[5] 刘佑荣,唐辉明.岩体力学[M].北京:化学工业出版社,2008.
[2] 张莉萍,许宝田,邱德俊,等.南京秦淮东河黄马青组(T2h)砂岩水致劣化特征分析[J].工程地质学报,2018,26(2):391-399.
[3] XU BT, YAN C H, XU S. Analysis of the bedding landslide due to the presence of the weak intercalated layer in the limestone[J]. Environmental Earth Sciences, 2013(70):2817-2825.
[4] 中华人民共和国国家标准.工程岩体分级标准(GB/T 50218—2014)[S].北京:中国计划出版社,2014.
[5] 刘佑荣,唐辉明.岩体力学[M].北京:化学工业出版社,2008.