公路工程

为分析衬砌劣化对山区高速公路隧道抗震性能的影响，基于一般大气环境侵蚀作用分析了衬砌混凝土力学性能劣化特性，利用钢筋锈蚀机理确定了衬砌钢筋性能劣化特性。基于地震危险性及易损性理论，构建了考虑衬砌混凝土与钢筋劣化的隧道抗震可靠度计算模型。以国内某山区高速公路隧道为工程案例，分别对其地震易损性、危险性与抗震可靠度进行了分析，并对比了不同衬砌劣化类型对隧道抗震可靠度的影响。研究表明：随着服役时间的增加，隧道地震易损性超越概率呈现非线性增加，服役前25年，隧道超越概率增加并不明显，服役后期隧道超越概率明显增大；当地震烈度一定时，随着服役年限的增加，隧道地震危险性的超越概率不断增加，但增加幅度逐渐减小；隧道抗震可靠度随服役时间的增加而不断下降，且下降幅值逐渐增大，服役前25年，抗震可靠度下降幅度较小，而服役后期抗震可靠度下降较为明显；随着服役时间的增加，不考虑衬砌劣化与考虑衬砌劣化(衬砌混凝土与钢筋共同劣化)的抗震可靠度差值逐渐增大，钢筋劣化较混凝土劣化对隧道抗震可靠度的影响更大。

To analyze the impact of lining degradation on the seismic performance of mountainous expressway tunnels, the mechanical properties of lining concrete are analyzed considering the general atmospheric environment erosion effect, and the degradationproperties of lining reinforcement are determined by the mechanism of reinforcement corrosion. Based on the theory of seismic risk and vulnerability, the calculation model of tunnel seismic reliability considering the deterioration of lining concrete and reinforcement is constructed. Taking a highway tunnel in a mountainous area in China as an engineering case, the seismic vulnerability, risk and seismic reliability of the tunnel are analyzed respectively, and the influence of different types of lining deterioration on the seismic reliability of the tunnel is compared. Research shows: with the increase of service time, the exceedance probability of tunnel seismic vulnerability presents a nonlinear increase, in the first 25 years of service, the exceedance probability of tunnel does not increase significantly, but increases significantly in the later period of service; when the seismic intensity is constant, as the service life increases, the probability of exceeding the seismic hazard of tunnels continues to increase, but the increase amplitude decreases gradually; the seismic reliability of tunnel decreases with the increase of service time, and the amplitude of decline increases gradually. In the first 25 years of service, the seismic reliability decreases slightly, but in the later period, the seismic reliability decreases obviously; with the increase of service time, the difference between seismic reliability without considering lining deterioration and with considering lining deterioration(joint deterioration of lining concrete and rebar) gradually increases, and the effect of reinforcement deterioration on tunnel seismic reliability is greater than that of concrete deterioration.