公路隧道的支护结构对交通安全具有重要意义.马鞍子梁公路隧道是复杂地质条件下的典型特长隧道,依据其Ⅴ级围岩岩性和初期支护参数,采用有限元法建立模型,从锚杆抵抗拉力、锚杆长度、喷层混凝土受力等方面计算结构安全系数,然后评价其可靠性.结果表明,初期支护的结构可靠度系数为0.588,若考虑二次衬砌的支护作用,可获得稳定的整体结构.
The supporting structure of the highway tunnel is important to traffic safety.Maanziliang highway tunnel is a typical long tunnel under complicated geological conditions.According to lithology of grade Ⅴ surrounding rock and primary support parameters,the structure factor of safety was calculated about bolt resistant tension,bolt length and shotcrete force through finite element method.As a result,the reliability was evaluated and the coefficient is 0.588,but integral structure will be steady if taking secondary lining into account.