现行规范对隧道同类围岩中某一点的塌方高度进行了统计，但未能考虑同类围岩长度范围内塌方高度的空间变异性，为此提出了围岩塌方高度空间等效方差增大函数σh(L)。同时运用Weibull—Бοлοгин脆性破坏统计理论，求得隧道空间结构所用混凝土的等效抗压强度fce；从而将同类围岩长度范围内的深埋隧道空间结构体系可靠度问题简化为平面问题。以金州隧道Ⅲ类围岩深埋段隧道空间结构为研究对象，分析了节理间距特征值、围岩塌方高度均方差上限，隧道长度等因素对其体系可靠度的影响。计算结果表明，节理间距特征值越大，可靠度指标越高；随着围岩塌方高度均方差上限及隧道长度的增长，可靠度指标逐渐减小，具有趋于稳定的趋势。

Height of similar rockmass landslides in one tunnel section was processed with the statistical method in the existing design codes.However, the spatial variability within the similar rockmass length was not taken into account.In order to overcome the shortcomings, an equivalent deviation increasing function of the space rockmass landslides height σh(L) was put forward.And the WeibullБοлοгин statistical theory for brittle materials failure was employed to find the equivalent compressive strength of tunnel secondary lining with different concrete volumes.As a result, the problem of space structural system reliability for the deepburied tunnel could be simplified as a plane problem.Taking the class Ⅲ deepburied rockmass in Jinzhou tunnel as an example, the characteristic values of joint spacing, variance upper limit of rockmass landslides height and the length of the tunnel to affect the system reliability were analyzed.And it was shown that the system reliability index increased with the increase of characteristic values.The system reliability index decreased gradually with the increase of variance upper limit of rockmass landslides height and the length of the tunnel.However, the reliability index would be towards a stable value at the end.

江南大学院长基金资助项目(HT200865)