深埋隧道层状岩体地应力反演研究

Study on inversion of in-situ stress of layered rockmass in deep buried tunnel

结合渝沙高速公路共和隧道地应力量测资料,通过调整多种组合的侧压系数,获得隧址区山体多组地应力。将每一组侧压系数下获得的测试段地应力,利用横观各向同性弹塑性本构模型对测试段层状岩体进行计算,并将计算的结果与实测结果对比分析,确定出隧址区山体合理的侧压系数,从而得到了隧道轴线方向的初始地应力大小和方向,研究表明,隧道轴线初始地应力与隧道的埋深和地形地貌有关,靠山侧初始地应力大于靠河侧,最大初始地应力主要集中在埋深500-1 000m,即K41＋500-K43＋000里程段,最大初始地应力为19.7MPa,与水平面的夹角为-71.58°。这为隧道设计和施工提供了重要的基础资料。

Based on the data of Gonghe tunnel in Yu-Sha express highway, different groups of in-situ stress in the tunnel site region are acquired by adjusting different coefficient combination of horizontal pressure. The in-situ stress of layered rockmass in sections of measurement is calculated by transverse isotmpy elastoplastic model. By comparing the two results, the reasonable coefficient of horizontal pressure in tunnel site region is confirmed and then the magnitude and direction of in-situ stress along the tunnel axes is obtained. The research shows that the in-situ stress along the tunnel axes is related to the buried depth of tunnel and the to stress near the mountain is larger than that near the river. The maximum of in-situ pography, that is, the in-situ stress, which is 19.7MPa, is mainly in the depth from 500m to 1 000m, namely, in the section of K41 ＋ 500 - K43 ＋ 000, and the angle with horizontal is -71.58°. The research provides some fundamental data for tunnel construction and design.