| China is the country with the largest scale and quantity of tunnel in the world.The complex structure of the tunnel and the large differences in the environment,coupled with internal and external factors such as load and material degradation,lead to potential risks in the tunnel structure and endanger operational safety.Understanding the interaction mechanism between the tunnel and the external environment and discovering the correlation and mutual feedback mechanism between the tunnel structure condition and the complex geological environment information is an important topic of tunnel evaluation and maintenance.Based on the long-term monitoring and disease remediation project of Zhangjiazhuang Tunnel of Lanzhou-Xinjiang High-speed Railway,this article studies the multi-source information correlation and Assessment method of the tunnel structural Condition during the operation period.The main research contents are as follows.(1)Fully investigate and master the research status of tunnel structural condition assessment,focus on the comprehensive application of multi-source information in the risk assessment of tunnel structure condition.Based on the structural diseases of the Zhangjiazhuang tunnel,determine the long-term health monitoring system architecture and build a spatial monitoring information model.(2)Carry out the correlation analysis between the stress monitoring value of the Zhangjiazhuang tunnel and the deformation trend of the surface Gaojiawan landslide,and explore the time lag of the tunnel structure stress change relative to the landslide.The spatial correlation between the stress distribution of the tunnel and the location of the landslide is studied,and the spatial-temporal correlation model between the stress difference and the landslide is constructed.Realize the time and space accurate prediction of the stress monitoring of the Zhangjiazhuang tunnel structure,and carry out the model test verification of the tunnel structure stress response under the landslide condition.The model shows that the stress hysteresis of different mileages in the remediation section has the characteristics of "small in the middle and large at both ends".The minimum and maximum positions of the lag time are located at K1759+455(3d)and K1759+152(>50d).(3)Fully excavate the monitoring data of Zhangjiazhuang tunnel structural stress,Gaojiawan landslide deformation,and regional temperature,combine with geological survey and design data,and disease detection results to construct a quantitative parameter model of daily average temperature,tunnel stress fluctuation range,and stress development trend.And use Hermite interpolation polynomial to complete the missing stress value and form a normalized processing method for stress monitoring data.A calculation method based on the load sharing ratio of each monitoring item is proposed.Finally,combined with numerical analysis,a reasonable characterization of the mechanical behaviour of the Zhangjiazhuang tunnel structure is realized.(4)Combining multi-source information such as tunnel monitoring data,design data,landslides,and temperature environment,and fully considering the correlation factors between the evaluation information,a dynamic weighted analytic hierarchy process with multi-source information and its correlation conclusions as the core is formed.When applying this method to evaluate the Zhangjiazhuang Tunnel,the evaluation scores of each location fluctuate within the dynamic adjustment range from-10.35% to 11.09 %.The proportion of tunnel safety grade distribution was that "safe structure with sufficient safety margin" accounted for 30.56%,"safe structure with certain safety margin but insufficient to cope with major disasters" accounted for47.22%,"safe structure with insufficient safety margin" accounted for 18.06% and "structure in a dangerous condition" accounted for 4.17%.The high-risk section of the tunnel structural condition assessment is consistent with the key position of the new round of renovation starting at the end of 2018. |
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