张集铁路玄武岩崩塌落石特征研究

Research on the Characteristics of Basalt Avalanche and Rock Falling Along Zhangjiakou-Jining Railway

研究目的:通过对张集铁路玄武岩崩塌落石特征的研究,探索玄武岩崩塌落石分布与地形地貌和地层结构的关系及形成机理,确立塌落岩块形态、运动轨迹,建立影响距离公式,为玄武岩地区铁路工程设计和防护措施的选择提供依据。研究结论:张集铁路玄武岩多位于地表和夹杂于砂砾土、粘性土和第三系泥砂岩中,覆盖在山顶上的玄武岩常形成危岩陡壁,是崩塌落石的主要来源;崩塌的严重程度与下伏地层及其产状有关,逆层山坡比顺层山坡更易形成崩塌落石;崩塌落石岩块多以块状和不规则球状为主,发生概率与体积呈反比。

Research purposes： Through studying characteristics of basalt avalanche and rock falling along Zhangjiakou - Jining Railway, the discussions are made on the relation between the fallen rock distribution and the structures of land form and stratum structure and on their forming mechanism for the purposes of defining the shape and movement trace of the fallen rock and establishing the formula for calculation of influencing distance of fallen rock to provide the bases for design and construction of railway in basalt area choosing protective measures.Research conclusions：The basalt along the railway often locates on the earth＇s surface and lies into sand, gravel and clayish soil, tertiary clay stone and sandstone. The basalt covering the mountaintop generally forms unstable steep cliff,which is the main source of avalanche and rock falling. The avalanche degree of basalt relates to undersurface stratum,that is to say, adverse hillside is easier to produce avalanche and rock falling than bedding hillside. The shape of fallen rock is usually block shape and anomaly ball and its appearing probability is opposite to the volume.