The real-time monitoring of the cutter wear was realized during TBM tunneling by installing a cutterhead working status monitoring system on the cutterhead of TBM in the tunnel section of the second bid, the Chaoer River to Xiliao River Water Conveyance Project. The whole life wear process curve for a single cutter was obtained on basis of the monitored data. The wear process of a single cutter could be divided into three stages, namely low cutter wear rate at the initiation stage, acceleration cutter wear stage and uniform cutter wear stage. The cutter edge shape had a significance impact on the cutter wear curve. Based on the rock mass conditions recorded during TBM tunneling process, combined with TBM operating parameters and monitoring data, the influence of the rock mass parameters and TBM operating parameters on the cutter wear rate was analyzed. The results showed that the cutter wear value per unit broken rock volume was suitable to measure the cutter wear rate, and the rock abrasivity, rock mass integrity and field penetration index were the key parameters to affect the cutter wear rate, which could provide a basis for the accurate cutter wear prediction model in the future research.

To clarify the equivalent blasting load for the periphery hole with air-deck charge, the refined numerical model for two contour holes with air-deck charge was established on the LS-DYNA platform, and the instantaneous blasting process was carefully simulated through fluid-solid coupling algorithm. As for the charge section, the surrounding rock were crushed immediately due to the intensive blasting pressure, while the tensile stress due to the superstition of two blasting pressures produced the main crack along centerline. The pressure time-histories along centerline were triangle-shaped, and the peak value attenuated sharply with blasting distance. As for the air section, no crush zone appeared surrounding the hole, while the superimposed tensile stress could still produce the main crack along centerline. Comparing to the charge section, the pressure time-histories along centerline were characterized by multi-peaks, while the peak value decreased substantially and the duration increased notably. The peaks of real blasting load were averaged along centerline, which yielded the equivalent blasting load with ladder-type. The equivalent blasting load reflected the main features of real blasting load in a simplified way, which could provide some technical supports for the further numerical simulation about far-field vibration.

The problem that the stress and displacement of surrounding rock in loess tunnels may cause large errors based on the Mohr-Coulomb strength criterion. A new solution for calculating the stress and displacement of the surrounding rock of the loess tunnel was derived based on the quadratic parabolic strength criterion, which could comprehensively consider the tensile and shear strength characteristics of the loess. The analysis showed that the peak value of tangential stress of tunnel surrounding rock appeared at the elastic-plastic interface. The peak value of tangential stress based on quadratic parabolic strength criterion was 6.1% lower than that based on Mohr-Coulomb strength criterion, and the stress in plastic zone of the former was smaller than that of the latter. The plastic zone radius of loess tunnel surrounding rock increased with the decrease of supporting force. When the supporting force was small, the plastic zone radius of the former was larger than that of the latter, and the smaller the supporting force, the greater the difference between the two. The peripheral displacement of loess tunnel increased with the decrease of supporting force, the former was larger than the latter, and the difference between the two increased gradually with the decrease of supporting force. By comparing the surrounding rock stress of the loess tunnel under different strength criteria with the model test results, it was found that the surrounding rock stress of the loess tunnel based on the quadratic parabolic strength criterion was in good agreement with the model test results. It showed that the surrounding rock stress, plastic zone radius and tunnel surrounding displacement of loess tunnel based on the quadratic parabolic strength criterion were closer to engineering practice.

Aiming at low accuracy of recognition in complex leakage images of subway tunnels, this paper studied the application of image recognition algorithms in tunnel water-leakage disease, was using two kinds of neural networks: U-Net and PSP-Net. Based on the subway tunnel images, tunnel leakage disease sample data set was constructed, where 5000 subway tunnel disease image data and 4000 labeled images were included. This data set could be used for deep neural convolution network training. U-Net and PSP-Net deep learning frameworks were established, and the neural networks were trained by self-made data set. The accuracy of the prediction results from U-Net and PSP-Net was evaluated, and the performance of the two networks in the application of leakage disease identification was compared. U-Net had stronger coverage for the disease and quick detection, while PSP-net had higher accuracy fit to fine detection.

By comparing the field test statistics of the surrounding rock pressure of 23 shield tunnels and 44 NATM(new Austrian tunnelling method, NATM)tunnels, the relationship between the surrounding rock pressure of shield tunnels and the buried depth, tunnel diameter and stratum type was studied. The difference between the surrounding rock pressure of shield tunnels and the NATM tunnels was analyzed, and the characteristics of the surrounding rock pressure of shield tunnels were further clarified. The applicability of each surrounding rock pressure calculation formula to the shield tunnel was discussed through calculation and analysis. It was found that the surrounding rock pressure of the shield tunnel increased with the buried depth, and the surrounding rock pressure of tunnels in loess and silty clay stratum was obviously less than that in stratum containing sandy soil. The surrounding rock pressure of NATM tunnels showed an obvious increasing trend with the increase of buried depth and excavation hole diameter. The surrounding rock pressure of the shield tunnel and NATM tunnel was quite different. Due to the timelier lining support of the shield tunnel, the surrounding rock pressure of the shield tunnel was significantly higher than that of the NATM tunnel, and the distribution of surrounding rock pressure along the tunnel perimeter was more uniform. The surrounding rock pressure of the shield tunnel was more inclined to belong to deformation pressure.

In order to solve the large deformation problem of Shanenshan No.2 Tunnel of the China-Lao's Railway, the design principle of the support resistant limiting damper(SRLD)was introduced, and the energy-consuming support scheme with the SRLD was designed according to the field working conditions from the point of rational utilization of the load-bearing capacity behind the peak of the surrounding rock. Based on the comprehensive analysis of the working state, structural deformation and internal force monitoring results of the primary support of the test section, the rationality of using the SRLD to treat the tunnel with carbonaceous SLATE stratum was verified. The results showed that after tunnel excavation, the system energy was dissipated mainly through the plastic strain energy of surrounding rock, while the energy dissipated by support was limited. Therefore, if the plastic deformation ability of surrounding rock could be fully utilized and the energy could be dissipated by surrounding rock itself, the energy conservation and conversion could be accomplished, thus reducing the pressure of surrounding rock. The SRLD was a pressure yielding control system, suitable for small eccentric pressure environments controlled by deformation pressure, which assised the surrounding rock to dissipate energy in an elastic-plastic state under reduced surrounding rock pressure, without damage. The SRLD was successfully applied in the double-lane section of Shannon Hill Tunnel No. 2, which significantly reduced the pressure on the surrounding rock compared to the “strong support and hard roof”, and avoided problems such as cracking of the initial support and buckling of the steel frame without strengthening the initial support parameters, thus improving the economy of the project while ensuring safety.

In order to cope with the risk of sudden fire and reduce the damage caused by the fire, it was necessary to investigate the performance change trend of the gasket under high temperature, and then the mechanical properties and sealing performance of the gasket after high temperature were verified. The material selection and hole type selection of sealing gasket were investigated. In view of the influence of high temperature on gasket material, the thermal oxidizing aging test of rubber specimen was carried out under high temperature condition and the material property loss was measured. The main research findings were as follows: it was found that the engineering industry tends to adopt “Shesfield type” sealing gasket made of EPDM ma-terial, and the hole type was mostly circular double row hole. After aging at different temperatures, the overall material property of medium or low hardness(40 HA, 60 HA)EPDM materials showed a downward trend, while the tensile strength of 80 HA EPDM material had a high hardness increases first and then decreases. Under high temperature conditions, EPDM would have a large material loss, which would affect the sealing performance of the sealing gasket at the segment joint at the material level, and reduced the long-term waterproof reliability of the joint. The research results have guiding significance for the scientific evaluation of the service performance evolution of shield tunnel joint gaskets.

In order to explore the shear characteristics of sand, the finite element method was used to simulate the triaxial compression experiment of sand with a subplastic constitutive model and the accuracy was verified. The model was used to carry out some analysis on the influence of the initial conditions of the sandy soil on the shear mechanical properties of the sandy soil. The research results showed that the model had high accuracy and could reflect the stress-strain relationship of sand under triaxial compression experiments, and the confining pressure and compactness of sand had significant effects on the hardening characteristics and shearing phenomenon of sand during shearing impact. Based on the simulation results, the effects of various parameters in the hypoplastic constitutive model on the deviatoric stress and volumetric strain during the shearing process of sand were further analyzed.

In order to timely alarm the deformation and damage of underground water supply pipelines under the influence of the stratum deformation caused by the excavation of the adjacent foundation pit, and make up for the deficiencies of the existing municipal pipeline information management platforms in the intelligent early warning service module for the monitoring of adjacent construction disturbances, the theory of the displacement field calculation around the foundation pit and the underground pipeline failure criterion was introduced, based on which, a warning model and the corresponding digital procedure for the damage of deformed underground water supply pipelines utilizing the monitoring data of the foundation pit was established. The corresponding microservice module was developed based on the infrastructure Smart Service System(iS3)independently developed by Tongji University. The real-time deformation estimation and damage warning of underground water supply pipelines near the foundation pit were achieved in an engineering project, which provided a tool for the risk scenario deduction for the safety analysis on underground water supply pipelines in extreme cases.

At present, the evaluation method of TBM construction suitability under different large deformation levels was lacking. The suitability classification standard of TBM method for soft rock tunnel was established by analyzing the mechanism of large deformation in soft rock, summarizing the classification methods, and considering the influencing factors of TBM tunnelling. It was divided into five classes: very suitable, suitable, more suitable, poorly suitable and unsuitable, and the reasonableness of the method was verified by engineering examples. This method could provide a reasonable reference basis for the classification of large deformation in soft rock tunnels and the evaluation of the suitability of TBM, and then selected suitable construction methods and prevention measures.

Aims at the situation that the influence of the seepage water pressure of the surrounding rock on the stress and displacement of the surrounding rock of the deep-buried tunnel is not clear, based on the spatial mobilized plane(SMP)strength yield criterion and non-correlated flow law, the elastic-brittle-plastic analytical solutions of tunnel surrounding rock stress and displacement under seepage water pressure were derived, and the effect laws of seepage water pressure and shear dilatation on the displacement and stress of tunnel surrounding rock were analyzed. <b>Results</b> showed that, the infiltration water pressure had a significant effect on the stress and displacement of the surrounding rock. With the increase of the infiltration water pressure, the stress and displacement of each point of the tunnel and the radius of the plastic zone increased, and the greater difference between the water head inside and outside the tunnel, the greater change of the stress, displacement and the plastic zone radius, among these, the plastic zone radius and the infiltrating water pressure had a linear positive correlation. The results of this research are of great significance for accurately determining the seepage water pressure of surrounding rock around the tunnel and ensuring the stability of the surrounding rock.

Relying on the Shenzhen Metro Line 13 project, a comprehensive set of shield muck treatment process was established, along with a set of treatment equipment according to the component characteristics of the muck, which efficiently realized the rapid separation of gravel, sand and mud cake in the shield muck. The technology has high treatment efficiency, outstanding separation effect and excellent economic and environmental benefits.