Earth pressure balance shield tunnel boring machines (EPBM) are widely used in tunneling practice yet the mechanics that define ground-EPBM interaction, specifically the advance rate, are not well understood. In the study presented here, machine learning techniques including feature selection, support vector regression (SVR) and partial dependence plots (PDP), were successfully applied to EPBM data

Computational Fluid Dynamics (CFD) simulation results, obtained with FDS 6.0.1, are presented of reduced-scale tunnel fire tests with longitudinal mechanical ventilation and an activated water spray system. This is a sub-set of a more extensive data set, in the context of blocking fire-induced smoke tunnel tests conducted previously. As discussed in Sun et al. (2018), CFD can complement the experimental

In this study, a series of full-scale fire tests are performed in a tunnel with large cross-sectional vertical shafts. The heat release rates and fire locations are considered, and the general smoke development, smoke flow pattern in the shaft, smoke temperature distribution, and smoke front velocity are analysed. It is found that complete plug-holing occurs in the tunnel with large cross-sectional

The artificial ground freezing (AGF) is one of the most popular ground-support methods. Driven by its reliability, compatibility with a wide range of ground types, and low impact on the environment, the AGF became one of the most favorable geotechnical-support methods in various mining, civil, and environmental projects. Over the last few decades, there has been a growing interest in the AGF. Several

The form of utility tunnel is increasingly used nowadays for urban development. Considering the ease and the speed of construction, a novel prefabricated utility tunnel structure is proposed. Analytical calculation is conducted to derive the longitudinal equivalent flexural stiffness, from which the design detail of “wall chamfer” is found to have minimum influence. The leakage behaviour of the proposed

The safe and cost-effective excavation of mountain tunnels requires appropriate prediction and evaluation methods for ground conditions ahead of the tunnel face, since appropriate choice of support members and auxiliary tunneling methods depends on such data. The authors have developed a new prediction method based on monitoring tunnel crown inclination in the direction of the tunnel axis and have

Fault fracture zones are adverse geological conditions often encountered in the constructions of mountain tunnels. Extensive structural damage to the mountain tunnels in adjacent to the fault fracture zones has been documented in the past earthquakes. In current work, three-dimensional numerical model of a water conveyance tunnel crossing multiple active strike-slip faults was established to assess

Gas leakage from buried gas pipelines in urban areas can lead to accidents involving fire and explosion when the gas gets concentrated into the adjacent underground spaces. Determining monitoring points for the gas leakage in the underground spaces can prevent the initiation of fire and explosion. In this regard, this study proposes an optimized distribution model which relies on risk prediction. It

Coal burst induced by fault-slip in longwall mining can adversely influence underground mining activities. This paper analyses the source mechanisms of fault-slip behaviour using a numerical fast Lagrangian analysis of continua in three dimensions (FLAC3D) model. The fault was simulated by the build in zero-thickness interface elements. The post failure process of fault-slip was studied using the linear

Fractures in rock masses not only are main flow conduit for groundwater, but also provide planes of weakness on which further displacement can more readily occur. Grouting has been widely used to reduce the permeability of fractured rocks, as well as to improve the stability of fractured rocks. Therefore, fractures infilled with grout appear extensively in practice, and may be subjected to different

The incoming directions and incoming angles of near-fault (NF) seismic waves may play important roles in potential seismic-induced damage to hydraulic arched tunnels due to the uncertainty and randomness of NF ground motions. Moreover, the correlation between the seismological characteristics of NF ground motions and the seismic behaviour of underground structures, especially hydraulic arched tunnels

Disconnectable coupling (DC) joint is an important connecting device in support system, and its bearing capacity, which is usually inaccessible, has a crucial impact on the support system’s bearing capacity. In order to quantitatively study the bearing capacity of a DC joint and propose relatively accurate formulas for calculating its yield load and compression stiffness, indoor axial loading tests

A series of dynamic centrifuge tests were performed to analyse the seismic response and failure mechanism of the underground frame structures. In the model test, the model structure experienced complete collapse, which has rarely been reported in previous studies. This study aimed to obtain an effective numerical model based on physical tests that could properly simulate large deformations or even

A series of scaled fire tests were conducted in a model bifurcated tunnel to investigate the influence of ramp slope on fire behaviors of ethanol pool fire under natural ventilation. Four ramp slopes of 0%, 3%, 6% and 9% with three fuel areas were varied. The maximum ceiling temperature in main tunnel and longitudinal temperature decay along the ceilings of horizontal main tunnel and ramp were measured

Within a major tunnelling-infrastructure project in Southern Germany, the mineral anhydrite of the rock “Grabfeld Formation” (formerly “Gipskeuper”) proved to be challenging with respect to the prohibition of the use of water. Due to its bulking potential (swelling) when anhydrite interacts with water (gypsum) the use of water was prohibited during the complete process of tunnelling works. This led

This paper presents a new method of foundation improvement for high embankment culverts on soft foundation; high strength exchanging-fill materials are adopted to partially replace the foundation soil, and a lattice-shaped diaphragm wall is thus formed. Based on the actual project, a field test was conducted to study the working performance of the culvert. In this project, a reinforcement bridge was

The geological conditions of the underground caverns in the Jinping I hydropower station are particularly complicated, with high ground stress (the extreme value of the measuring point is 35.7 MPa), complicated deformation and failure mechanisms, and large unloading depth. The large deformation of the surrounding rock mass was beyond current engineering and academic understanding. During the construction

The method of using steel plates to strengthen existing tunnel linings has been widely applied in many tunnel rehabilitation projects around the world. However, the effectiveness of the strengthening resulting from this method is still unclear, especially for conditions when the segmental linings are deformed to a relatively large extent. In this paper, a series of physical model tests conducted in

The traditional method of buried utilities (i.e. water, sewer and gas pipes, and electrical and tele-communication cables) has been using for many decades particularly in urban areas. Repeated excavations are needed to access these underground utilities for maintenance, repair, and renewal activities. Urban areas have been experiencing many street closures and traffic disruptions because of excavation

Accurately predicting the performance of a tunnel boring machine (TBM) is important to safe and efficient tunneling. The application of machine learning algorithms to TBM performance prediction creates several challenges. Such prediction is a nontrivial task involving procedures such as data preprocessing, selection of a machine learning algorithm and optimization of the related hyperparameters. The

In this study, a new technique for predicting roadways stability in tunneling and underground space was proposed based on a combination of particle swarm optimization (PSO) algorithm and artificial neural network (ANN), called ANN-PSO model. The dataset from five tunneling and underground mines in the 2006-2019 period was recorded monthly and used for this aim with 145 observations. Accordingly, the

The time-dependence of rock strength is an issue that cannot be ignored in the rock engineering field. This paper summarizes previous study results on the degradation of the uniaxial compressive strength of rock (including component cohesion and internal friction angle), tensile strength and Young's modulus over time. Based on previous studies, the degeneracy formulas of intact rock cohesion and internal

Along with the development of urbanization, an increasing number of subsurface voids in urban cities can have serious effects on the expected functionality of key infrastructure elements such are roads. Ground penetrating radar is an effective technique for imaging the subsurface and detecting such air voids. The GPR responses of air voids with different horizontal width were quantitively investigated

The double deck system of road tunnel is of large cross-section. To investigate its characteristics under dynamic action large-scale shaking table tests are performed. Through comparison the seismic performance between a double deck tunnel model and a simple tunnel model, the effects of interior structure on the seismic performance of the segmental linings are investigated. The detailed responses of

The atrium-style station is one of the favourite choices in underground railway systems, as it can provide a larger and clearer space for passengers and commercial clients at the hall level of the station. With such style, as hall slabs are replaced with flat-beams, the station's capabilities to withstand lateral action like seismic action become one of the main concerns. Shaking table tests were conducted

Point-attack picks have been widely used in mechanical excavators, such as roadheaders, long-wall shearers, and trenching cutters. Different parameters (i.e., cutting conditions and mechanical properties of the rock) affect the cutting performance of point-attack picks. Among the parameters, skew angle is an important parameter that affects the cutting performance (i.e., cutter forces and specific

The surrounding rock deformation during tunnelling is difficult to be measured or calculated accurately, especially in tunnels constructed by double-shield TBM. A method for prediction of the crown convergence deformation of surrounding rock based on advance borehole monitoring and numerical inversion analysis is proposed. Combined with the field deformation monitoring and numerical simulation, the

The probabilities of exceedance of the maximum tensile stress in cement-stabilized soft clay, the displacement of retaining structure and bottom upheave are explored with deterministic finite element method and fuzzy finite element approach (FFEA) for a Shanghai pit excavation. Effect of the scale of fluctuation on the probability of exceedance is clearly observed. In the cases with an infinite scale

The density and unsustainable placement of buried utilities in the limited underground space lead to coordination issues between utility owners and increase the social costs because of repeated excavations. Multi-purpose utility tunnels (MUTs) integrate all utilities in one tunnel that can be easily accessed for inspection and maintenance activities, which can be conducted all-year-round irrespective

One of the main factors that affect the tunnel face stability is the free or unsupported span (i.e., the unlined length adjacent to the tunnel face). In this work, a 2D failure mechanism is developed to compute, in the context of Limit Analysis, the collapse pressure for tunnel faces in Mohr-Coulomb materials, considering the free span. The new mechanism comprises three non-deformable blocks (two translational

Given the frequent cost overruns and schedule delays associated with tunnel construction projects, it is imperative that a detailed estimation of both be developed and considered prior to starting construction. To this end, two artificial intelligence tools of Gaussian Process Regression (GPR) and Support Vector Regression (SVR) were used to forecast geology, construction time and construction costs

Ground support and reinforcement technology can greatly enhance the stability of underground excavations and make the underground infrastructure safer. This paper investigates a combined support methodology aiming at increasing the stability and safety of soft-rock roadways in the Zhongguan iron mine in China via analysis of the field structure of weak surrounding rock by means of numerical modelling

The research carried out full-scale fire experiments for smoke movement and control in an underground double-island subway station. Four kinds of fire scenarios were designed in the station hall and platform respectively, and series of thermocouples were arranged in the public space. Several vital fire parameters were analyzed, including the vertical temperature distribution, the longitudinal temperature

Longitudinal ventilation is widely employed for smoke control in tunnels due to its relatively low installation cost and compactness. However, smoke control using a longitudinal ventilation system becomes complex when applied in a multi-branch sloping tunnel. In sloping tunnels, the stack effect and forced longitudinal ventilation may combine to produce multiple smoke flow patterns, even under identical

Fiber reinforced concrete, with different types of fibers, has been increasingly used in underground structures, especially for tunnel lining segments. Macro synthetic fiber reinforced concrete has a considerable structural bearing capacity. Compared to steel fiber reinforced concrete, it has the advantage of corrosion resistance and durability. However, the main application of macro synthetic fiber

Plug-holing of the smoke layer is an unfavorable phenomenon for the smoke extraction efficiency in the naturally ventilated tunnel with vertical shaft. In this work, theoretical analysis and large eddy simulation (LES) are carried out to investigate how to prevent the occurrence of the plug-holing phenomenon and improve smoke extraction efficiency. The results show that the occurrence of plug-holing

The Daikai Station failed during the 1995 Kobe earthquake. Detailed analyses of the seismic response of the station had been conducted under the assumption of a drained response of the ground; that is, no excess pore pressure accumulate during the cycles of loading. Such assumption is supported by the location of the water table around the station, which was depressed, compared to locations far from

In engineering construction, the elastic-slip interface often exists around the tunnel. An elastic-slip interface model is proposed to analyze the dynamic response of underwater convey tunnel, and the surrounding soil is assumed to be saturated poroelastic medium. The reflected, refracted and scattered waves in the free surface water, the surrounding soil medium and the tunnel are expressed by wave

Waterproofing heavily influences the operation and maintenance costs of underground structures. Currently, the most commonly used technology for tunnel waterproofing is plasticized polyvinyl chloride (PVC-P) geomembranes. However, not much is known about the long-term durability of these geomembranes, especially in relation to the long expected lifespan of new tunnels (i.e. 100–150 years). Therefore

The performances of a long and deep excavation and underlying collinear existing tunnels in Shenzhen granite residual strata are presented and evaluated. The collinear section for the excavation and tunnel had a length of 3.1 km and the maximum excavation depth was 18.0 m. The excavation was supported with retaining piles, one level of reinforced concrete strut, and 1–3 levels of steel pipe strut.

Excessive floor deformation in underground coal mines, known as floor heave, can cause production delays and thus financial losses. This paper presents parametric studies using numerical models to understand the mechanisms of floor heave in coal mine roadways. An Australian longwall coal mine that experienced significant floor heave in the roadways, where a strong floor unit overlying weak floor units

In this paper, a novel non-planar interlocking element is developed, which can be used to construct cylindrical structures. The proposed element has a symmetrical geometry with six curved side surfaces to be interlocked with adjacent elements. A tubular structure can be constructed by assembling a number of identical non-planar elements, and the movement of each element is naturally restricted in all

Fibre reinforced concrete (FRC) is increasingly used in tunnel segmental linings constructed with tunnel boring machines. Several codes include the FRC as a structural material and specific guidelines cover the design of FRC precast segmental linings. All of these consider the traditional limit state format, applying partial safety factors to the loads (γL) and material strengths (γM). Often, the γM

Downward flame spread over insulation materials by restriction of parallel glass curtain wall is an important potential scenario in modern underground building fire accidents. Meanwhile, considering the continuous challenge of research efforts in low pressure fire behavior, experimental investigation was conducted for the individual and coupling effects of pressure and curtain wall spacing on flexible

The rationality of formulas 22, 27 and 28 in the paper by Qi Zhang et al. (2019) were discussed due to its derivation process. The reason for this irrationality was analyzed in detail and the relationship between RMR89 and RMR14 under the condition of considering only discontinuities of rock mass was extracted. On this basis, a more reasonable formula has been proposed to replace formula 22. And another

The effects of hydro-mechanical coupling in fractured rock mass on groundwater inflow into underground openings were investigated using numerical simulations and case study. The groundwater inflow were obtained with different stress field configuration, fracture shear dilation behavior and fracture orientations The interplay of stress field configuration and fracture orientation on both fracture aperture

A multi-layer repository concept is proposed as an alternative to the single-layer repository concept to improve the disposal density of high-level radioactive waste (HLW) in Korea. Numerical simulations are performed to compare the coupled thermo-hydro-mechanical (THM) behavior in the existing Korean reference HLW disposal system (KRS) based on the single-layer repository concept to that in the new

Passive bolting is used to stabilise unstable rock blocks in surface and underground structures due to the various advantages it offers. Despite its use, the design phase still presents aspects of considerable complexity because the fact that the load of the bolt and therefore, its static action depends on its interaction with the block and the stable rock. In the present work, a mathematical model

The Junchang tunnel is a part of a major project in the Censhui highway in Guangxi province, China. The weathered granite part of the tunnel is approximately 180 m long with two lines and four lanes. Numerous water and mud inrush disasters frequently occurred in the weathered granite area, leading to serious economic loss and challenge to the constructors. Therefore, continuous grouting was carried

One highly effective approach for tunnelling in rock at deep depth is blasting. The damage and in-situ stress redistribution in the surrounding rock mass induced by the blast loading during this process is, however, unavoidable. In this study, a powerful GPGPU-parallelized combined finite-discrete element method is implemented to study the damage evolution during controlled contour blasting in the

The rapid development of underground construction results in safety problems in surrounding environments due to ground surface settlement. Comparing accumulated settlement with threshold to evaluate settlement risk is insufficiently accurate. Thus, identifying the location and change in the settlement risk is difficult. This research develops a data-based complex network approach to analyze and assess

The hybrid ventilation system combining forced longitudinal flow and shaft natural ventilation has the advantages of both ventilation strategies; for example, it can discharge buoyant smoke through the nearest downstream shaft and can actively constrain backlayering flow. A series of brine-water experiments were conducted to investigate the effects of the longitudinal velocity and shaft dimensions

Rock indentation is the basic process in drilling and excavation from the mechanical points of view. A better understanding of the fundamental mechanism of rock-indenter interaction is of great significance. This paper proposes a semi-analytical model (SAM) to analyze rock fragmentation processes induced by indentation loads. In SAM, the analytical expressions of the stress and strain relationship

Measurement-While-Drilling (MWD) data are complex because of the drilling process and drilling system. Swift and accurate normalization and filtration processes are required if MWD data are to be used for rock mass characterization. The current method for MWD data filtration does not consider all the effects of the drilling process, e.g., collaring or extension rod coupling. This paper presents a new

A series of numerical simulations about tunnel fires are carried out to study the performance of different arrangements of natural ventilation shafts in a 500 m tunnel. Two to four identical shafts are arranged in a group at the centerline and the sideline of the tunnel ceiling. The characteristics of the temperature distribution, velocity field and the total amount of smoke exhausted from each shaft

According to the factors affecting the stability of the integral load-bearing structure of the surrounding rock of a retained gob-side entry, the load-bearing capacity of roadside supports with flexible concrete formwork is studied to propose a new integrated supporting control technology. This approach is based on a bolt and anchor cable support with a wire mesh for retaining the surrounding rock

Structural performance of shield tunnels is of paramount concern during their long-time service. This work presents a case study describing the structural responses of a shield tunnel caused by unexpected leakage and the corresponding treatment measures. Firstly, the general information of the accident is introduced, and the structural responses of segmental lining are highlighted, e.g., longitudinal

A utility tunnel typically houses various types of urban lifelines. As one of the assembled pipelines in a utility tunnel, the sewer pipeline is of great importance for city life. For example, leakage of toxic and combustible gases and a subsequent explosion can result in severe accidents. The potential hazards in the sewer pipeline compartment of a utility tunnel are greatly different from those in