Tunnel Conditions Research Articles

Numerical Investigation with Failure Characteristic Analysis and Support Effect Evaluation of Deep-Turning Roadways

In recent years, tunnel-boring machines (TBMs) have been widely applied in deep coal mining. Turning is an inevitable challenge in TBM tunneling, and a TBM turning roadway exhibits greater instability than a straight roadway, as engineering experience has indicated. This study aimed to explore the failure mechanism and evaluate the support performance of a deep-turning roadway. Several numerical models were established to investigate the deformation of the roadway, the stress distribution, and the failure zone of the surrounding rocks under different tunneling conditions. The results show that the tunneling depth influences the failure pattern of the turning roadway: deep tunneling with high in situ stress can cause asymmetric failure of the turning roadway, while shallow tunneling with low in situ stress does not. Moreover, the change in turning radius, namely the change in roadway geometry, does not influence the stability of the turning roadway. In addition, the support actions for both the straight and turning roadways do not differ significantly, and the amount of controlled deformation of the surrounding rocks is proportional to their natural deformation.

A Theoretical and Experimental Investigation of the Effects of Inverted Wings Modifications on the Stability and Aerodynamic Performance of a Sedan Car at Cornering

ABSTRACTThis research examines the impact of cornering on the aerodynamic forces and stability of a Nissan Versa (Almera) passenger sedan car by introducing novel modifications. These modifications included single inverted wings with end plates as a front spoiler, double‐element inverted wings with end plates as a rear spoiler, and incorporating the ground as a diffuser under the car trunk. The goal is to enhance the performance and stability of conventional passenger cars. To ensure the accuracy of the numerical data, the study utilized multiple methodologies to model the turbulence model, ultimately selecting the most suitable option. This involved comparing numerical data with wind tunnel experimental data using force balance and pressure distribution. Once validated, the computational fluid dynamics (CFD) was employed to analyze the vehicle's aerodynamic performance relative to the straight‐line condition under cornering conditions. The car simulation in a cornering condition was conducted at a representative Reynolds number based on the vehicle length of about 1.3 × 107. The study discovered that asymmetry was a recurring theme regarding surface pressure distribution, with greater prominence under cornering conditions. All modified models exhibited a more favorable lift‐to‐drag ratio than the baseline, indicating improved aerodynamic efficiency. The underbody double‐element diffuser proved most effective for enhancing fuel efficiency and stability. Mesh refinement with a polyhedral algorithm consisting of 11.27 million elements and a computational domain with a frontal area of 91.8 m2 and a curved length of 31 m (˜7 times car length) was crucial for achieving accurate and repeatable results. The study employed multiple turbulence models within the CFD framework. The realizable k‐ε model was chosen due to its balance between accuracy and computational cost for all Nissan Versa models. These findings are limited to the selected parameters and wind tunnel conditions, and further investigations might be needed for extreme driving scenarios.

Effect of Drip Irrigation Regimes and Mulching on Cucumber Production under Cooled Plastic Tunnel Conditions, Kassala State, Sudan

An experiment was conducted in a cooled plastic tunnel greenhouse during March-August of 2022 and 2023, the objectives of this study to investigate the effect of drip irrigation regimes and mulching on yield and yield components of cucumber under greenhouse conditions, Kassala, Sudan. Seedlings of the most popular cucumber hybrid (Fatin) were planted on 40cm and 50 cm inter and intra-row spacing, respectively. The experiment was composed of two factors; the irrigation regimes (75%, 100% and 125% of recommended irrigation water) and the other was mulching (mulching and no mulching). These factors were arranged in split plot design with three replications. The main plots were allocated for irrigation regimes and subplots for mulching. The subplot size was 200cm×70cm (bed/mastaba). Results reported that125% of recommended irrigation water (RIW) under drip irrigation recorded highest yield and yield components in both seasons. Moreover, the highest values of yield and yield components; fruit length, fruit diameter and fruit weight were obtained under 125% of (RIW) with mulch while, the lowest were obtained with75% of (RIW) without mulch on both seasons. The highest values of water productivity and economic water productivity were recorded under 125% of (RIW) with mulch. On the other hands, the highest marginal rate return (MRR) was obtained under 100% of (RIW) with no mulch.

Modeling Multi-Factor Coupled Pressure Fluctuations in EMU Trains under Extreme Tunnel Conditions

Modeling Multi-Factor Coupled Pressure Fluctuations in EMU Trains under Extreme Tunnel Conditions

Variability in strawberry tunnels impacts fruit quality and limits melatonin effects.

Fluctuations in environmental conditions within fields and crop plant performance can greatly affect production and quality standards. These factors are particularly relevant for producers, who require sustained optimal production to profit from small margins. Fluctuations might be exacerbated at the end of the crop season, where neither of the aforementioned factors are optimal. In the present integrated study, we assess strawberries' nutritional quality and the impact of harvest timing, tunnel conditions and inter-individual variability in a Mediterranean production tunnel divided into blocks, where two harvests were performed 3 weeks apart. In addition, the effects of sprayed melatonin at the end of productive season were also evaluated. End-season harvesting negatively impacted fruit hydration, antioxidant capacity and ripening-related hormones in strawberry fruits. Additionally, tunnel distribution influenced fruit nutritional quality, with light radiation being the main variable factor disturbing antioxidant contents. Nutrients exhibited high inter-individual plant variability, accounting for 20% variation, and were strongly correlated with fruit hydration and ripening-related phytohormones. Finally, melatonin applications affected neither fruit production, nor nutritional parameters, for which the effects were masked by the intrinsic strawberry variability. Overall, the results underline the limitations of this type of application for field implementation. Fruit quality variation in strawberry fields is explained by environmental and inter-individual variability. Likewise, the implementation of regulatory molecules such as melatonin in field applications relies on crop homogeneity and might have limited applicability in heterogeneous productive systems. Consequently, identifying and reducing microclimate variability in productive fields is paramount for advancing agricultural practices to uphold unwavering standards on fruit quality. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Comparative Study of Ginger Cultivars under Shading Conditions in a High Tunnel

Ginger (Zingiber officinale Rosc.) is a valuable sciophyte crop used as a spice or fresh herb in culinary dishes and for treating medical issues such as osteoarthritis, neurological diseases, vomiting, and asthma. The demand for ginger in the United States is remarkably high; it is produced commercially and exclusively in Hawaii but can only meet ∼20% of US demand. Light for ginger growth may be more important than is often assumed, but the roles of light in ginger growth and rhizome yield are not fully understood. We hypothesized that artificial shade would produce the highest yielding ginger compared with no shade. This study evaluated the impact of different shading suited for ginger growth and rhizome yield of different cultivars grown in a high tunnel. There were three levels (0%, 22%, and 40%) of shade using RCBD design. We analyzed the overall yield (weight) of ginger and the specific yield (weight) of different rhizome parts (biological root, edible root, and seed ginger) per plant in addition to plant growth data. Data were analyzed for 2018 and 2019, and shade conditions influenced ginger growth and yield. There was no significant difference between shade conditions or cultivars, but general trends found that data differed between the two growing seasons. In 2018, Chinese White and Hawaii Yellow produced a better (higher) yield under 0% and 40% shade. However, in 2019, Chinese White and Hawaii Yellow produced the highest total yield under 22% shade, but Bubba Blue produced the highest overall yield at 0% shade.

In-tunnel pollutant concentration measurement and ventilation control indexes for highway tunnels in mountainous area: A case study of no.1 Qinling tunnel, China

The pollutant concentration and hygiene standards in mountain tunnels are key factors determining the ventilation effectiveness of tunnel operation. Previous studies have mainly focused on the spatiotemporal distribution patterns of in-tunnel pollutants, while research on ventilation control indexes for pollutants in long mountain tunnels are relatively limited. Therefore, this paper aims to discussing the hygiene control indexes for operational ventilation of mountain tunnels. Field tests were conducted in the No.1 Qinling Tunnel of Xi'an to Han zhong Highway in China, and the distribution laws of traffic flow, wind speed, and concentrations of particulate matter (PM), carbon monoxide (CO), and nitrogen oxide (NOX) were on-site measured. The spatiotemporal distribution characteristics of pollutants in the long mountain tunnel were revealed, and the ventilation hygiene control indexes for harmful gases were calculated and compared to those of urban highway tunnels. The results show that the traffic volume of operational highway tunnels in mountainous areas of China is increasing rapidly, and the particulate matter emitted from diesel vehicle exhaust will pose a threat to the normal environmental quality in the tunnel. The average value of CO base emission factor in 2000 for the upline of No.1 Qinling tunnel was 0.0019 m3/(veh·km) by back-calculation, and the annual decline rate of CO in the ventilation design for mountain highway tunnels should be 6 %–8 % and revised every 8 years. It is recommended to consider the geographical location and traffic conditions of mountain tunnels when calculating the air demand required for diluting NO2. NOx has basically replaced CO as the primary pollutant with the most significant impact on human health in mountain tunnels. It is recommended that NOX be considered as the primary hygiene control indicator in the ventilation design of mountain tunnels in China. The pollutant distribution and ventilation control indexes of mountain and urban highway tunnels are quite different, which should be treated differently in engineering applications. The research results can provide a significant reference for ventilation design and environmental evaluation of highway tunnels in mountainous areas.

Specialty Melons Grown under High Tunnel Conditions Yield Good to Excellent Internal Quality

Interest in local foods, especially locally grown fruit, is increasing. High tunnel vegetable growers are strategically poised to meet this demand by growing specialty melons (Cucumis melo). Although specialty melons are commonly grown in high tunnels in other parts of the world, it is an uncommon practice in the midwestern United States. The objectives of this study were to evaluate 10 specialty melon cultivars for high tunnel production and measure fruit yield and internal quality. Fruit of the cultivar Eden’s Gem yielded the greatest number of marketable fruits per plant; however, these melons are small and have a loose cavity. Fruit of the cultivars Honey Orange and Divergent yielded the largest marketable fruit per plant with tighter cavities; however, the cavities were large. All cultivars had good to excellent internal quality in terms of sugar content. The production of specialty melons in the high tunnel was successful, resulting in the production of melons with good to excellent internal quality, and several yielded three to four marketable fruit per plant. Implementing a strong pest management plan for cucumber beetle (Diabrotica undecimpunctata howardi) and powdery mildew (Erysiphe cichoracearum, Sphaerotheca fuliginea) is recommended to prevent yield loss, especially in locations such as the Midwest, where cucumber beetles often vector bacterial wilt (Erwinia tracheiphila).

Tailored directional porosity in ceramic matrix composites (CMCs) for hypersonic applications

AbstractIn the field of hypersonic systems and their missions, the occurring flows impose extreme mechanical and thermal loads on the materials used. At the German Aerospace Center (DLR), extensive research is conducted in this area, ranging from design and specification to the development of suitable materials concluding with the proof of concept under realistic conditions in wind tunnels. In recent years, ceramic matrix composites (CMCs) have been investigated for specific aspects of hypersonics. These materials exhibit consistent mechanical behavior over a wide temperature range (up to 1600 °C), coupled with high damage tolerance and thermal shock resistance, distinguishing them from metals and superalloys. Particularly, special porous C/C–SiC ceramics (carbon-fiber-reinforced carbon with silicon carbide) enable innovative material applications for components in transpiration cooling, fuel injection, or boundary-layer transition control. The work presented focuses on the next generation of porous C/C–SiC ceramics currently in development. By deliberately modifying the textile preform, the resulting microstructure and pore morphology are influenced, allowing for control over both the total volume and the orientation of the pores. Relevant parameters influencing porosity have been determined based on the results, and an initial characterization has been conducted. It has been demonstrated that there is a preferred direction of porosity within the sample thickness (Z-axis), and in terms of hypersonic-relevant properties, an absorption coefficient of 0.58 for an acoustic wave at 500 kHz (static pressure of 15 kPa), as well as a length-specific flow resistance of 3.4 MPa s/m2 and an overall porosity of 12.25% were determined. Building upon these promising initial findings, the goal is to further expand the understanding of the parameters influencing porosity and to generate a tailored material for different application scenarios by correlating them with hypersonic properties.

TBM adaptability analysis in small-radius curved tunnels in Kurkar strata in Israel

In shield tunnelling, both alignment and geological conditions not only influence the performance of the tunnel boring machine (TBM) but also affect disturbance of the strata. Based on an analysis of the challenges posed by alignment and geological conditions, a targeted design was implemented for a TBM for small-radius curved tunnels in the Kurkar strata in Israel. The adaptability of the TBM was verified through a comprehensive analysis of strata disturbance, variations in boring parameters, tunnel alignment and cutter wear. The results indicated that, to accommodate small-radius curves, the TBM could be adapted by shortening the shield length, setting articulation cylinders and configuring overcutting tools. To adapt to the Kurkar strata, 2.5‰ of foaming agent (CLB F5/M) can be added, along with appropriately increasing the soil chamber pressure. The TBM parameters can be set as follows: total thrust 20 000–24 000 kN, cutterhead rotation speed 1.3–1.4 rpm, TBM advance rate reaching 30–45 mm/min and cutterhead torque ranging from 2500–3500 kN.m. Double-disc cutters should be avoided in the Kurkar strata, especially in central regions of the cutterhead.

Evaluation of priority index for enhancing the seismic resilience of tunnels

Tunnels are essential infrastructure elements, offering significant economic, social, and environmental benefits. However, they are particularly vulnerable to seismic risks, especially in regions with high seismic activity. Given their importance in terms of safety, economy, and social factors, it is crucial for the relevant authorities to prepare for natural and human-made disasters by enhancing the seismic resilience of tunnels. In Algeria, where the number of tunnels is high, this necessity is particularly urgent.This article proposes a prioritization model aimed at improving the seismic resilience of tunnels, based on the expertise of specialists and structured into three main steps. The first step involves identifying key criteria, including the tunnel's condition, design phase, availability of alternative routes, social importance, geometric shape, and seismic zone. The second step applies the Analytic Hierarchy Process (AHP) to calculate the weights of the criteria and incorporates expert opinions through the Euclidean Distance-Based Aggregation Method (EDBAM). Finally, the third step establishes the Priority Index for Tunnel Seismic Resilience Improvement (PIT).The model was tested on five tunnels, and the classification obtained based on the priority index was found to be well aligned with the observed reality on the ground.

Study on the influence of combined utilization of air-fog curtain on fully mechanized face

To address the ambiguous regulations for dust control and removal in the joint use of air curtain and fog curtain, this study developed a multi-field coupling model of airflow, dust, and droplets. By incorporating the spraying method into both traditional ventilation technology and air curtain technology, this study comparatively analyzed the dust control and removal efficiencies of these two methods under various ventilation conditions in tunnels. The spray experiment and simulated result indicated a maximum relative error of 19.9%. The simulation results demonstrated that the use of traditional ventilation technology resulted in significant dust contamination in the rear and top regions of the tunnel. Although the dust pollution was ameliorated when the pressure-suction ratio was 1.25, the dust control effect remained unsatisfactory, with the pollution distance extending 37.0m. After implementing air curtain technology, the airflow generated a spiral air curtain due to the wall attachment effect, effectively confining the majority of dust to the heading face area. When the axial flow ratio was 45%, the dust concentration at exceeding 13.0m from the heading face dropped to blow 1.0mg/m3, significantly reducing health risks for operators.

Random Lasing under Dissipative Tunneling Conditions in a Network Quantum Material

A new mechanism of the generation of a random laser based on a random photonic network with dissipative tunneling of photons between microcavities that are placed at the nodes of such network and contain identical two-level quantum systems has been revealed. It has been shown that an additional source of photon losses in tunneling promotes the separation of individual modes of the random laser and the achievement of the lasing threshold even at a vanishingly small population inversion. In this case, the enhancement of laser modes has an interference nature and is due to the energy redistribution between the nodes of the photonic network that correspond to different signs of the frequency detuning of stationary modes of the random laser from the transition frequency of two-level systems. It has been shown that the traditional lasing mechanism, which demonstrates features of the spectrum of single microcavities, i.e., is almost independent of the topological properties of the network and the tunneling parameter, is present in the region of zero detuning.

Study on Leakage Assessment and Stability Analysis of Water Level Changes in Tunnels near Reservoirs

The geological and hydrological conditions of tunnels near reservoirs are complex, and the impact of water level changes on the stability and leakage assessment of the lining structure is not considered in the current leakage evaluation. In order to construct an evaluation model for leakage level of tunnels near reservoirs, the influences of water level changes on tunnel stability and changes in environmental conditions on the leakage of tunnels were researched. Based on the AHP and extensibility theory, a hierarchical system for leakage assessment was created, incorporating values from nine indexes representing three aspects: geological conditions, hydrological conditions, and tunnel engineering. Numerical simulation was used to analyze the influence of water level changes. It was found that the water level change index greatly influences the displacement and stress distribution inside the tunnel structure. The leakage evaluation model was applied to the Tiebeishan Tunnel, resulting in a rating of 3, indicating medium-level leakage. Attention should be paid to water leakage in tunnels with changes in reservoir water levels. The leakage evaluation model for tunnels near reservoirs can effectively assess leakage levels under various conditions, providing a reference for safety assessments of tunnel leakage near reservoirs.

Postharvest dehydration of red grapes: impact of temperature and water-loss conditions on free and glycosylated volatile metabolites of exocarp and epicarp of Nebbiolo and Aleatico varieties.

Postharvest dehydration affects the metabolism of grapes, impacting odorous secondary metabolites and therefore the features of the corresponding passito wines - high-quality products with winemaking practices linked to specific territories and related autochthonous grape varieties. Water loss and temperature conditions are the main variables of the dehydration process. This study assessed how they impacted the patterns of free and glycosylated volatile organic compounds (VOCs) of the exocarp (pulp) and epicarp (skin) in Nebbiolo and Aleatico, a neutral and semi-aromatic red grape variety, respectively. Dehydration parameters were set in tunnel conditions, and VOCs were quantitatively analyzed by solid phase extraction-gas chromatography-mass spectrometry. For Nebbiolo grapes, weight loss had a greater impact on free volatiles than dehydration temperature, with a 20% weight loss increasing total VOCs in both exocarp and epicarp. Low temperature (10 °C) significantly increased (P < 0.05) the glycosylated VOCs' terpene content. In Aleatico grapes, weight loss was key in modulating free volatiles, with 30% weight loss and 15 °C leading to significant increases in VOCs, especially exocarp terpenes, acids and benzenoids. More stressful dehydration (30% weight loss at 25 °C) resulted in higher aroma precursor concentrations. These findings can assist passito wine production in preserving varietal aromas of original grapes trough optimized dehydration conditions, preventing sensory homologation occurring because of strong uncontrolled dehydration. They can also promote optimization of energy consumption, thus fostering financial and environmental sustainability. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Tunnel construction worker safety state prediction and management system based on AHP and anomaly detection algorithm model

Tunnels represent complex, high-risk, and technically demanding underground construction projects. The safety of construction workers in tunnels is influenced by various factors, including physiological indicators, tunnel dimensions, and internal environmental conditions. Analyzing safety based solely on static factors is inadequate for modern tunnel engineering safety management requirements. To address this challenge, this paper provides a comprehensive analysis of factors impacting safety and employs the Analytic Hierarchy Process (AHP) to identify seven significant factors with high importance: body temperature, heart rate, internal temperature, internal humidity, CO concentration, chlorine concentration, and the relative positioning of personnel. Considering these factors essential for assessing worker safety, we introduce a novel model named Tunnel-APH-AD. For training models aimed at anomaly detection, we performed data augmentation and utilized four distinct machine learning models. Additionally, ensemble learning techniques were applied to aggregate the predictions from individual models, thereby enhancing the effectiveness of detecting safety states for tunnel workers. We also evaluated the performance of these models on out-of-distribution (OOD) samples to test their robustness and generalizability. The experimental results indicate that, under similar ventilation and tunnel conditions, the ensemble learning model exhibits superior overall performance compared to individual models, underscoring the effectiveness of model combination in improving the accuracy and reliability of safety alerts. Through experimental validation, this study provides interpretable, scalable, and scientifically generalized applications of machine learning theories in systems for tunnel construction worker safety alerts. These findings contribute to advancing safety management practices in tunnel engineering, enabling proactive and effective measures to mitigate potential risks and ensure the well-being of workers.

Local Excitation of Kagome Spin Ice Magnetism Seen by Scanning Tunneling Microscopy.

The kagome spin ice can host frustrated magnetic excitations by flipping its local spin. Under an inelastic tunneling condition, the tip in a scanning tunneling microscope can flip the local spin, and we apply this technique to kagome metal HoAgGe with a long-range ordered spin ice ground state. Away from defects, we discover a pair of pronounced dips in the local tunneling spectrum at symmetrical bias voltages with negative intensity values, serving as a striking inelastic tunneling signal. This signal disappears above the spin ice formation temperature and has a dependence on the magnetic fields, demonstrating its intimate relation with the spin ice magnetism. We provide a two-level spin-flip model to explain the tunneling dips considering the spin ice magnetism under spin-orbit coupling. Our results uncover a local emergent excitation of spin ice magnetism in a kagome metal, suggesting that local electrical field induced spin flip climbs over a barrier caused by spin-orbital locking.

Efficient Mako Shark-Inspired Aerodynamic Design for Concept Car Bodies in Underground Road Tunnel Conditions.

The automotive industry continuously enhances vehicle design to meet the growing demand for more efficient vehicles. Computational design and numerical simulation are essential tools for developing concept cars with lower carbon emissions and reduced costs. Underground roads are proposed as an attractive alternative for reducing surface congestion, improving traffic flow, reducing travel times and minimizing noise pollution in urban areas, creating a quieter and more livable environment for residents. In this context, a concept car body design for underground tunnels was proposed, inspired by the mako shark shape due to its exceptional operational kinetic qualities. The proposed biomimetic-based method using computational fluid dynamics for engineering design includes an iterative process and car body optimization in terms of lift and drag performance. A mesh sensitivity and convergence analysis was performed in order to ensure the reliability of numerical results. The unique surface shape of the shark enabled remarkable aerodynamic performance for the concept car, achieving a drag coefficient value of 0.28. The addition of an aerodynamic diffuser improved downforce by reducing 58% of the lift coefficient to a final value of 0.02. Benchmark validation was carried out using reported results from sources available in the literature. The proposed biomimetic design process based on computational fluid modeling reduces the time and resources required to create new concept car models. This approach helps to achieve efficient automotive solutions with low aerodynamic drag for a low-carbon future.

Research on ventilation cooling design driven by human thermal response in high geothermal temperature tunnel construction

Constant high temperature conditions in tunnel not only significantly reduced the labor efficiency of workers but also affected their physical and mental health. However, the traditional design of ventilation and cooling for high geothermal tunnel construction only considers the control of environment temperature and ignores the thermal comfort state of the workers, which will increase the potential risk of tunnel safety accidents. Therefore, this paper adopted the methods of scene testing, theoretical analysis and numerical simulation to establish a modified evaluation model applicable to the thermal comfort of workers in high geothermal tunnels. By analyzing the temperature distribution pattern of heat-sensitive parts of workers engaged in different labor intensity under different air supply parameters, the design strategy for ventilation and cooling of high-temperature tunnels was refined on the basis of ensuring that the environment temperature and thermal comfort meet the requirements. The results show that ventilation design parameters that satisfy the environmental temperature control criteria are equally adequate for worker thermal comfort at light-intensity work. However, when the ambient temperature is higher than 40 °C, the thermal comfort of workers engaged in medium-intensity work still does not meet the requirements, even if the ambient temperature already meets the criteria. It is recommended that the wind speed be increased by at least 8.3 %, 15.6%and 28.6 % for ambient temperatures of 40 °C, 45 °C and 50 °C, respectively. More effective cooling techniques should be tried to further enhance thermal comfort for workers engaged in heavy workloads especially in hot environments exceeding 40 °C.

Dynamic reliability evaluation of TBM components in tunnel construction

The complex geological conditions in tunnels pose a huge challenge to the reliability of tunnel boring machine (TBM). However, existing reliability studies typically focus on core structures such as cutters and cutterheads, with less consideration given to the rest of the components that frequently fail. In this study, the reliability analysis and dynamic evaluation of TBM components with high failure rates are carried out relying on the Shanxi Central Yellow River Diversion Project. The life distribution and reliability variation characteristics of TBM components under different rock mass classes are investigated in terms of tunnelling time and tunnelling distance as two types of life data indexes. And the life index which is more suitable for the reliability evaluation of TBM components is identified by comparison. On this basis, a dynamic evaluation method for the reliability of TBM components under the condition of multi‐classes surrounding rock is proposed. This method can quickly evaluate the current reliability of TBM components and serve as the basis for preventive maintenance. The results of this study play a certain role in supplementing the reliability research of TBM and also provide a scientific basis for optimizing the design and maintenance strategy of TBM components.