Displacement Of Tunnel Research Articles

АНАЛИТИЧЕСКИЙ ПОДХОД К ОПРЕДЕЛЕНИЮ ПРОДОЛЬНОГО СМЕЩЕНИЯ СУЩЕСТВУЮЩЕГО СБОРНОГО ТОННЕЛЯ ПРИ ВЫЕМКЕ КОТЛОВАНА ПО ВСЕЙ ДЛИНЕ

In the realm of urban construction employing excavation techniques, safeguarding existing underground structures from detrimental consequences arising from surface construction operations poses a formidable challenge. The reduction of loads due to excavation activities can induce unintended responses, potentially jeopardizing subterranean infrastructure, particularly high-safety-demanding structures like Tunnel Boring Machine (TBM) tunnels. This article introduces an uncomplicated method for ascertaining the axial displacement of TBM tunnels amidst concurrent surface excavation activities. Primarily, the approach entails the identification of stress variations encountered during soil excavation at the tunnel face. Subsequently, employing the solutions derived for the determination of tunnel deformation subjected to concentrated loads, the deformation incurred by the tunnel due to alterations in excavation-induced stress is quantified. The analytical outcomes are meticulously juxtaposed against results generated from a three-dimensional computational model. The comparative analysis demonstrates that the displacement values and axial deviations calculated using the proposed analytical method exhibit only marginal disparities of 4,3% and 1%, respectively, when compared to those obtained through finite element analysis. This study underscores the efficient predictive capabilities of the analytical method in assessing tunnel deformations, enabling a preliminary estimation of critical parameters associated with the excavation pit. These findings have significant implications for mitigating adverse impacts on existing subterranean infrastructure in densely populated urban areas.

Numerical Simulation Study of the Vibrational Response of Continuous Arch Tunnels under the Action of Overlying Train Loads

With the rapid development of transportation infrastructure in China, continuous arch tunnels passing under existing operational railways are increasingly encountered. This paper primarily investigates the mechanical response patterns of the lining of continuous arch tunnels under the vibrational loads generated by trains traveling on railways. To this end, a three-dimensional finite element model of the dynamic response of continuous arch tunnels under train vibrational loads was constructed using Midas GTS/NX software. This model explores the patterns of acceleration, dynamic displacement, and dynamic strain responses of continuous arch tunnels under the action of moving train loads. The study reveals that under train vibrational loads, the vertical acceleration, vertical displacement, and strain time history curves at various monitoring points in the continuous arch tunnel exhibit vibrational characteristics. The acceleration, vertical displacement, and dynamic strain increase as the train enters, fluctuate within a certain range, and then decrease to zero as the train exits. Under high-speed train loads, the acceleration peak values at the arch feet and outer sidewalls of the left and right tunnels are larger, with a greater peak value difference. The vertical displacement peak values at the arch shoulders and crown are larger, whereas those at the middle partition wall and base slab are smaller. During the process from the train's entry to its exit, the dynamic strain exhibits a trend of initially increasing, then stabilizing, and finally decreasing to zero, all while displaying vibrational characteristics. The strain response on the tunnel side where the train enters is greater than that on the side where it exits.

Numerical Study on the Dynamic Response of Gas Explosion in Uneven Coal Mine Tunnels Using CESE Reaction Dynamics Model

A numerical simulation method combining the detailed chemical reaction mechanism of methane deflagration with an approximate real tunnel structure was proposed to confirm whether the unevenness of the tunnel wall during a coal mine gas explosion can be ignored. The approximate real tunnel model and smooth wall tunnel model were developed using 3D modeling methods. The propagation and attenuation processes of shock waves in the two tunnel models, as well as the different dynamic responses of the two tunnel walls, were compared and analyzed. Research results show that the non-uniformity of the tunnel wall decreases the shock wave overpressure and propagation velocity. The peak overpressure reduction value of the shock wave reaches 81.91 kPa, and the shock wave overpressure reaches its peak at an extended maximum time of 7.4 ms. The stress distribution on the approximate real tunnel wall is discontinuous, the propagation speed of stress waves in the bend tunnel is slower, and the duration of high load is relatively low. The displacement of the approximate real tunnel after gas explosion is lower than that of tunnels with smooth walls, and the displacement of most measuring points on the tunnel on the right is only 1/3–1/2 that of the smooth tunnel.

Analytical approach for the design of composite linings in deep tunnels considering the blasting damaged zone

Tunneling using the drilling and blasting method induces a blasting damaged zone around the tunnel, which affects the tunnel stability as well as the resulting support design. In this article, an analytical model that represents the whole-process interaction between the sequentially installed composite linings and the surrounding rock in the presence of the blasting damaged zone is proposed. First, assuming the blasting damaged zone to be a finite cylinder with decreased mechanical parameters, four ground forms according to the distribution of plastic zone are categorized and solved. Furthermore, the fictitious pressure concept is adopted to represent the three-dimensional effect of tunnel advancement, and thus, the construction process of the tunnel can be simulated. After that, the evolution patterns of the whole-process interaction between the composite linings and ground are distinguished. The critical distances and tunnel displacements between different forms in various interaction stages are identified and solved. Finally, the analytical solutions for tunnel displacement and structural responses can be obtained, based on the displacement compatibility conditions between composite linings and the ground. The analytical model is validated by numerical simulations through several typical examples, and the applicability in actual tunnel support design is verified by field monitoring results. Comparisons with an existing model and the conventional convergence-confinement method illustrate the inherent nature and advantages of the proposed model in the support system design. It is found that the blasting damage effect is significant on the tunnel responses, which should be considered in the support design. The proposed model provides a convenient feasible approach in determining the stiffness and support time of the composite linings for tunnels using the drilling and blasting method.

Structural displacement and deformation of adjacent shield tunnel induced by foundation pit excavation

Excavating a foundation pit close to a tunnel will unavoidably impact the nearby soil, causing the tunnel to shift and deform. Examining the longitudinal displacement and convergence deformation of a nearby shield tunnel during foundation pit excavation is crucial for maintaining safe operations. Nevertheless, most of the current research primarily focuses on the effects of a single foundation pit excavation on existing tunnels. This study examines and analyzes the effects of multiple foundation pit excavations on the displacement and deformation of pre-existing tunnels, using a project at a subway station as a case study. By employing the PLAXIS three-dimensional finite element software, a large-scale computational model based on the HS model is established, and then five dangerous working conditions are selected for simulation analysis. The research findings delineate that: (i) The displacement of the tunnel is affected by various factors. These encompass the magnitude of the foundation pit excavation, the positioning of the foundation pit excavation in relation to the tunnel, and the closeness of the tunnel to the foundation pit. (ii) The deformation encountered by the tunnel is largely influenced by external loads, where the scale of the unloading load primarily determines the deformation characteristics of the tunnel.

Seismic Stability of Tunnels in Multiple Silty Soils: Plastic Deformation

The escalating demand for efficient transportation infrastructure necessitates the construction of numerous tunnels, particularly in densely populated areas. However, their response to dynamic loads, like earthquakes, remains a critical concern. This study utilizes numerical modeling to assess the dynamic behavior of tunnels embedded in various silty soil types under seismic excitation. Employing Abaqus software and the finite element method, tunnels were modeled within three distinct silty soils: silty stone, silty sand, and low plasticity silty clay. Ground motion data from the 1994 Northridge earthquake was used as input to evaluate tunnel displacements. The results demonstrated significant variations in tunnel behavior based on the surrounding soil. Notably, low plasticity silty clay exhibited the largest displacements, followed by silty sand and silty stone. This emphasizes the crucial influence of soil properties on tunnel stability during seismic events. Future investigations could expand upon this work by incorporating additional soil parameters and utilizing more intricate soil models to yield even more precise predictions of tunnel response under dynamic loading conditions.

A semi-analytical method for stress-strain analysis of tunnels under dip-slip faulting based on an elastic-plastic foundation beam model

Tunnels under faulting will be seriously damaged, and an accurate analytical method is an effective tool for tunnel response assessment in preliminary design. A series of mechanical analytical methods have been developed for tunnels under faulting. However, some unrealistic assumptions are still employed in the analytical method for tunnels under dip-slip faulting, including tunnel segmentation, constant stratum stress, and axial force in governing equations of tunnel displacement, which increases the solution complexity and decreases the accuracy. In this paper, a tunnel crossing an active fault is simplified as a large deformed continuous beam acting on an elastic-plastic foundation, and the tunnel-stratum interaction is treated as a series of axial and vertical elastic-plastic springs; the elastic-plastic tunnel-stratum interaction stresses and axial force are considered in the governing equations by using the finite difference method and a novel iterative method. In this way, the three assumptions employed in the existing analytical methods are removed. Later, the proposed method is verified by comparing it with the results from the model test, numerical simulation, and existing method. The comparisons show that the results of the proposed method agree excellently with those from the model test and numerical model, and the accuracy is higher than that of the existing analytical method. Finally, the failure scope and stress distribution of tunnels under the action of normal and reverse faulting are analyzed in detail.

Seepage Actions and Their Consequences on the Support Scheme of Deep-Buried Tunnels Constructed in Soft Rock Strata

The stability of deep soft rock tunnels under seepage conditions is of particular concern. Aiming at thoroughly discussing seepage actions and their consequences on the support schemes of such structures, the host rocks of the Weilai Tunnel situated in the Guangxi province of China are used as the research subject. Emphasis is placed on adequately examining the seepage conditions, stresses, displacements and plastic zone radii along the surrounding rocks of such tunnels, taking into consideration the Mogi–Coulomb strength criterion and the elastic-plastic theory. Explicitly, this article proposes analytical solutions for stresses, displacements and plastic radii around deep tunnels in soft rocks under seepage conditions by considering the aforesaid criterion and nonlinear elastoplastic approaches. Subsequently, based on the strain-softening model, the coupled actions of seepage and softening on the rocks surrounding the tunnel are studied. In order to investigate the effects of relevant influencing factors on tunnel stability, parametric studies are thoroughly examined. According to the results, it is revealed that the support scheme of deep soft rock tunnels must be of the highest resistance possible to better decrease the plastic zone and the tangential stress along the host rocks. Moreover, throughout the surrounding rocks, the dissemination of pore water pressure is strongly affected by the uneven permeability coefficient under anisotropic seepage states. The combined effects of softening and seepage are very dangerous for the surrounding rocks of deep-buried tunnels. It is also shown that the seepage pressure substantially affects the plastic radii and tunnel displacements. Under high seepage pressure, the surface displacements of the tunnel are excessive, easily exceeding 400 mm. To better guarantee the reasonable longevity of such tunnels, the long-term monitoring of their support structures with reliable remote sensors is strongly recommended.

3D Monitoring Model for Real‐Time Displacement of Metro Tunnel under “Dual Carbon” Background

Real‐time automatic displacement monitoring of metro tunnels is vital for ensuring operational safety and contributes to carbon reduction goals by improving system efficiency. This study focuses on key monitoring elements such as displacement, settlement, convergence, and cracking. Through the analysis of continuous monitoring data, a real‐time displacement monitoring model for metro tunnels based on robotic total stations is proposed. This model can timely identify potential risks, thereby ensuring the safe operation of tunnels and reducing carbon emissions from unnecessary maintenance operations, thereby reducing the carbon footprint of metro operations. This article takes the Jinan Metro Tunnel Displacement Real‐time Monitoring Project in China as a case study and constructs a comprehensive monitoring framework using robotic total stations, intelligent automated deformation monitoring data collectors, and cloud servers. The implementation details of the project, displacement monitoring principles, monitoring system construction, and data analysis processes are elaborated in detail. Taking the monitoring data of Jinan Metro Line 2 from April 1, 2022, to May 31, 2023, as an example, the results show that the tunnel displacement is within the safe range, verifying the practical application value of the method proposed in this paper. It can effectively ensure the safe operation of the metro and promote sustainable development and low‐carbon metro construction.

Influence of Static and Repeated Surface Surcharge Loadings on Tunnel Displacement Considering Small-Strain Stiffness of Soft Clay

With the rapid development of urban metro tunnels, the effect of surface surcharge loading on existing tunnels is unavoidable. Accurate evaluation of soil deformation and tunnel displacement under surface surcharge loading is of great significance for practical engineering. In this research, the effect of static and repeated surface surcharge loadings on tunnel displacement in soft clay was investigated numerically. The hardening soil model with small-strain stiffness (HSS model) was adopted to simulate the soil response. The parameters of the HSS model were obtained through geotechnical tests. The result indicates that Shanghai layer 4 soft clay exhibits large soil shear stiffness in the small strain range. Tunnel displacement is closely related to parameters of surface surcharge loading width, burial depth of tunnel, and the horizontal distance from the centerline. The overlapping influence range of tunnel displacement was proposed. Under repeated surface surcharge loadings, the first cycle of the repeated surface surcharge loading has the greatest effect on the tunnel displacement, and the subsequent cycles of loadings still cause further increases in the tunnel displacement. The effect of repeated surface surcharge loadings on tunnel displacement gradually decreases as the burial depth of tunnel and the number of cycles increase.

Analysis of the interaction between bolt-reinforced rock and surface support in tunnels based on convergence-confinement method

To investigate the interaction of the bolt-reinforced rock and the surface support, an analytical model of the convergence-confinement type is proposed, considering the sequential installation of the fully grouted rockbolts and the surface support. The rock mass is assumed to be elastic-brittle-plastic material, obeying the linear Mohr-Coulomb criterion or the non-linear Hoek-Brown criterion. According to the strain states of the tunnel wall at bolt and surface support installation and the relative magnitude between the bolt length and the plastic depth during the whole process, six cases are categorized upon solving the problem. Each case is divided into three stages due to the different effects of the active rockbolts and the passive surface support. The fictitious pressure is introduced to quantify the three-dimensional (3D) effect of the tunnel face, and thus, the actual physical location along the tunnel axis of the analytical section can be considered. By using the bolt-rock strain compatibility and the rock-surface support displacement compatibility conditions, the solutions of longitudinal tunnel displacement and the reaction pressure of surface support along the tunnel axis are obtained. The proposed analytical solutions are validated by a series of 3D numerical simulations. Extensive parametric studies are conducted to examine the effect of the typical parameters of rockbolts and surface support on the tunnel displacement and the reaction pressure of the surface support under different rock conditions. The results show that the rockbolts are more effective in controlling the tunnel displacement than the surface support, which should be installed as soon as possible with a suitable length. For tunnels excavated in weak rocks or with restricted displacement control requirements, the surface support should also be installed or closed timely with a certain stiffness. The proposed method provides a convenient alternative approach for the optimization of rockbolts and surface support at the preliminary stage of tunnel design.

Inversion of Surrounding Red-Bed Soft Rock Mechanical Parameters Based on the PSO-XGBoost Algorithm for Tunnelling Operation

In constructing hydraulic tunnels, construction disturbances and complex geological conditions can induce variations in the surrounding rock parameters. To navigate the complex non-linear interplay between rock material parameters and tunnel displacement during construction, this study proposes a hybrid learning model. It employs particle swarm optimization (PSO) to refine the hyperparameters of the eXtreme Gradient Boosting (XGBoost) technique. Sensitivity analysis and inversion of rock parameters is performed by using orthogonal design and the Sobol method to analyze the sensitivity of environmental and rock material factors. The findings indicate that the tunnel depth, elastic modulus, and Poisson ratio are particularly sensitive parameters. Mechanical parameters of the rock mass, identified through sensitivity analysis, are the focal point of this research and are integrated into a three-dimensional computational model. The resulting tunnel displacement calculations serve as datasets for the inversion of the actual engineering project’s surrounding rock mechanical parameters. These inverted parameters were fed into the FLAC3D software (version 7.0), yielding results that align closely with field measurements, which affirms the PSO-XGBoost model’s validity and precision. The insights garnered from this research offer a substantial reference for determining rock mass parameters in tunnel engineering amidst complex conditions.

Elastic analytical method with machine learning for predicting the stratum displacement field induced by shallow tunneling

Support vector regression (SVR) with sparrow search algorithm (SSA) is developed as the machine learning (ML) model to predict maximum surface settlement smax caused by tunneling. A novel method for calibrating boundary conditions of analytical solution is proposed, where the maximum surface settlement derived by the analytical method is equal to smax predicted by SSA-SVR method. The elastic analytical solution for stratum displacement of a shallow tunnel is presented by the complex variable method, when the calibrated nonuniform displacement function is applied as the tunnel displacement boundary condition. The proposed analytical solution-machine learning (AM) method can predict the stratum displacement field prior to the tunnel excavation. Seventy-three tunnel engineering cases are employed to verify the rationality of the proposed SSA-SVR method in predicting smax. The value of R2 in the training and test process is 0.894 and 0.877, respectively. Taking Heathrow Express Trial Tunnel as an example, the potential of the proposed AM method in predicting stratum displacement is presented where the influence of cohesion strength, internal friction angle, Young's elastic modulus of stratum, tunnel radius and depth are considered. The proposed AM method can well predict the stratum surface settlement trough curve, vertical and horizontal displacement at different positions.

Expanding the Scene of Tunnel Behaviour Through the DEM Model: a Case Study from ZaB-Zentrum Am Berg

The displacement of a tunnel plays a crucial role in conventional tunneling methods, serving as a key parameter for support requirement. Therefore, analyzing tunnel displacement is important for ensuring safety and optimizing costs by determining the appropriate level of tunnel support and installation time. Numerical analysis methods are commonly employed for assessing tunnel displacement, and two widely recognized approaches used worldwide are the continuum and discontinuum methods. While previous studies have highlighted differences in the analysis results obtained from these two methods, the magnitude of such disparities has not been extensively explored. Hence, the objective of this study is to quantify the extent of variation between the two methods through various scenarios, encompassing unsupported and supported excavated ground. Specifically, the focus is on tunnel displacement and the tensile force generated on axial tunnel supports, such as rock bolts. To facilitate this investigation, three tunnel sections from the Zentrum am Berg, tunnel research centre located in Austria, are utilized. The results show that discontinuum models exhibit higher displacements and higher tensile loads on axial support than continuum numerical models of the same tunnel geometry and equivalent rock masses. We show that discontinuum models can also capture asymmetric behaviour, and thus should be preferentially used in fractured rock masses where displacement of rock blocks dominate the rock mass behaviour.

Study on the time‐dependent interaction between surrounding rock and yielding supports in deep soft rock tunnels

AbstractAs yielding supports can deform without being damaged, the yielding principle has attracted significant attention for tunnelling in squeezing ground compared with the heavy support method. The deformation energy of surrounding rock can be managed using yielding supports that maintain the rock pressure within the bearing capacity of the supports. However, although the yielding principle has been often applied in practical scenarios, a design method for yielding supports has yet not been well developed. This study discusses interaction between the squeezing ground and yielding supports and investigates the influence of the time‐dependent behaviour of rock on the yielding supports. The yielding supports can be implemented by the movement of sliding joints of steel arches or by shortening the yielding elements inserted in shotcrete linings. The deforming process of yielding supports can be divided into three stages: elastic a, yielding, and elastic b. A three‐stage pressure‐displacement relationship of yielding supports is proposed and a method is provided for the calculation of the support stiffnesses of yielding supports in different stages. Furthermore, a unified design approach for the yielding supports is presented and the theoretical model is established after simplifying the asymmetry of problem. The analytical solution for tunnel displacement and support pressure in a tunnel supported by the yielding supports is obtained. The proposed design method for the yielding supports is successfully applied to the Saint Martin La Porte access tunnel, and the mean tunnel deformation in this tunnel is appropriately predicted by the analytical solution. Additionally, a parametric investigation is performed based on the analytical solution, and the effects of yielding path, yielding displacement, support thickness, and installation time of the yielding supports are discussed. Finally, certain highlights of the analytical model of yielding supports in this study are identified, compared with other researches, and recommendations for the design of the yielding supports are provided. The outcome of this research has potential applications in the preliminary design of deep tunnels in squeezing ground.

Analysis and treatments of primary support failure in large-span tunnel under a soft-hard interbedded surrounding rock mass

The construction of large-span tunnels inevitably involves traversing uneven strata. Due to the influence of the flatness of the large-span tunnel structure and asymmetric surrounding rock loads, concrete cracking and excessive deformation of steel arches occur frequently. Taking a large-span highway tunnel with uneven rock strata as an example, the mechanical behavior, failure causes, failure mechanisms, and treatment techniques of the tunnel's initial support structure were studied. Firstly, field monitoring and systematic analysis of typical sections revealed that the displacement of tunnels on the soft rock side and the contact pressure between the surrounding rock and the support were significantly greater than on the hard rock side. Then, combined with the field test results, a similar model test was designed based on the tunnel structure performance testing platform developed by the research team to study the deformation and failure modes of conventional initial support systems for large-span tunnels under geological unbalanced pressure. Finally, an innovative technique is proposed to adjust external loads and optimize internal forces of the structure by locally adding long anchor rods or cables, and the treatment effects of various schemes are evaluated and compared. The results show that the initial support system exhibits a state of biased pressure in the presence of weak surrounding rock on one side. The maximum bending moment of the soft rock side spandrel bearing structure, the spandrel and vault on the soft rock side are the most vulnerable positions of the structure. By implementing local long anchor or bolts, the stress distribution within the initial support structure of a large-span tunnel can be effectively enhanced. This method offers significant practical value and flexibility, addressing the issue of initial support failure caused by a soft-hard interbedded surrounding rock mass in large-span tunnels.

Vertical Displacement Measurement of Tunnel Structures Based on Long-Gauge Fiber Bragg Grating Strain Sensing

Displacement monitoring systems play a crucial role in ensuring the safety of tunnels. Existing sensing technologies and analysis methods may be insufficient for monitoring tunnel displacement, particularly vertical displacement, due to the harshness of long-term monitoring conditions and the intricacies of structural characteristics. A long-gauge fiber Bragg grating (FBG) sensor can be used to obtain macro- and micro-level information and be connected in series for area sensing. In this study, a novel method was developed which utilizes long-gauge strain sensors to monitor the vertical displacement of a tunnel. This method employs a combination of mechanical analysis and monitoring data to accurately estimate the vertical displacement of the structure from the measured coupled strain. Several key aspects of the proposed method for identifying vertical displacement were investigated, including establishing a separation model of coupled strain on the cross-section, deriving the theory for vertical displacement identification, and determining the sensor layout of the tunnel. A series of simulation tests of a tunnel with a three-hole frame structure confirmed the efficiency and robustness of the proposed method, even when subjected to various loading conditions, noise levels, and sensor layouts. The results of this work may provide valuable insights and practical guidance for the effective and continuous displacement measurement of tunnels, ensuring their structural integrity and operational safety.

Effect of compressible layer on time-dependent behavior of soft-rock large deformation tunnels revealed by mathematical analytical method

The application of compressible layers is considered to be the most promising solution for solving the problem of large deformations in deep soft-rock tunnels. However, although significant effort has been devoted to understanding its mechanical working, the effect of the compressible layer has not been completely revealed. This study theoretically predicts the mechanical response of a deep soft-rock large deformation tunnel by applying a compressible layer. The theoretical model involves a circular tunnel, which is supported by a compressible layer and concrete lining, and subjected to a non-hydrostatic stress field. The influence of the tunnel face advancement is described by the stress release coefficient, and the three-stage deformation characteristics (elastic–yielding–compaction) of the compressible layer material are considered in this model. The entire tunnel deformation process is divided into unlined and lined (further subdivided into elastic, yielding, and compaction phases of the compressible layer material) phases. A series of complex potential functions in different media (rock, compressible layer, and concrete lining) and at different phases is provided; subsequently, the unknown coefficients in these functions are determined using the stress balance and displacement continuity conditions at different interfaces. Thus, the analytical solutions for tunnel displacement and support pressure at different phases are obtained. Good agreement between the numerical and analytical results is observed after performing the numerical simulation to validate the reliability and feasibility of the proposed analytical derivation. Finally, a parametric sensitivity investigation is conducted by including the yielding stress of the filling material, yielding length of the compressible layer, and installation time of the support. Adequate attention is paid to the tunnel displacement and support pressure on the 100th day and their development laws at the positions of θ = 90°, 45°, and 0° during the first 100 days. Some interesting findings are presented, and useful design suggestions for the compressible layer are provided.

Automatic monitoring and control of excavation disturbance of an ultra-deep foundation pit extremely adjacent to metro tunnels

This paper proposes an automatic monitoring and control system to control the construction disturbances of an ultra-deep foundation pit extremely adjacent to the operational metro tunnels. By real-time monitoring the structural response of tunnels and foundation pits, the reinjection wells and servo support system were automatically controlled to change the groundwater level and support axial force, respectively. All the relevant monitoring and control equipment was integrated into the system through Internet of Things technology. The field observations revealed that the proposed automatic monitoring-control system and framework can well control the excavation disturbance in adjacent metro tunnels. Under the ultra-deep excavation depth of 42.25 m and ultra-close spacing of 3.0 m, the maximum absolute value of the observed tunnel displacement was less than 5 mm. All the relevant structural responses of the tunnel and foundation pit were within limits. The wall deformation of the servo side is different from the common bulging deformation curve and is approximately 2 times smaller compared to the non-servo side. The observed tunnel deformation mainly changed at the excavation stage within the buried depth of tunnels. The presented system, data, advised control index and framework can provide useful guidance for similar scenarios.

Prediction of systolic displacement of tunnels by surface displacement

The method of surface displacement prediction of tunnel convergence displacement is used to make up for the failure of tunnel convergence displacement monitoring in the construction process, to supplement and verify the tunnel monitoring data, and to guide the construction. Firstly, some sets of systolic displacement and surface displacement data are obtained by field monitoring, which is used to calculate the parameter vector to be determined. The corresponding mathematical model is established and the systolic displacement of tunnel is predicted according to the monitoring data of surface displacement. Combined with field tunnel displacement monitoring and surface displacement monitoring, the correlation of displacement curve is analyzed, and the corresponding mathematical model is established. Combined with Matlab programming, the corresponding program language is written, the user interface is compiled, and the method of predicting tunnel convergence displacement by the ground displacement is realized.