Cracking and crushing were observed in the first tunnel lining of the Kaidagu double-arch tunnel (China), excavated in weathered surrounding rock. This concrete damage occurred during excavation of the second tunnel. It was necessary to monitor the continuous strain distribution along the entire cross section of the lining, so distributed fibre optic monitoring was carried out for nearly 1 year to

Influences of cutterhead of a shield machine on tunnel face stability have been rarely studied in the past. In this study, three-dimensional numerical analyses of face stability of shield tunnels were performed using discrete element method (DEM). In the DEM model, a shield machine with cutterhead panel and cutting tools was generated. The influence of the cutterhead and soil properties on the face

Optimization in TBM cutterhead design is essential for increasing its performance. Lace design for the cutters, buckets, and manholes in the cutterhead, is one of the major considerations in the design of the hard rock TBMs. An optimum lace design is necessary to avoid cutterhead deviation, vibration, and stress concentration during its operation. TBM manufacturers usually utilize two common lace designs

Current knowledge on seismic analysis of underground structures is limited to analytical solutions, numerical methods and scaled model tests. Virtual hybrid simulation (VHS) is an efficient and economical analysis method that combines numerical approaches and experiment methods while taking the advantages of both. In this study, a VHS method employing a multi-axial experimental setup for seismic analysis

The continuous monitoring of long-term performance of tunnels constructed in soft rock masses shows that the rock mass deformations continue after construction, albeit at a rate that reduces with time. This is in contrast with NATM postulates which assume deformation stabilizes shortly after tunnel construction. This paper proposes the prediction of long-term vertical settlement performance of a tunnel

In a segmental metro tunnel, it is widely observed that cracks, water leakage and other structural defects usually appear at segmental joint section of a smaller stiffness than main tunnel segment section. In this study, a 3D finite element analysis was conducted to simulate a typical concrete segmental joint explicitly using 3D continuum elements, and the performance of 3D continuum model was validated

In the past few decades, the number of tunnels constructed next to an existing tunnel has been gradually increasing in order to accommodate infrastructure needs in congested urban cities. When a new tunnel is constructed adjacent to an existing tunnel, both the relative position of the tunnels and the construction sequence affect the ground settlement and internal forces in the linings of both tunnels

This study analyzes the impact of different numbers of visible retroreflective rings on the drivers’ ability to perceive the curvature in curved freeway tunnels under different small radii. A driving simulator was used to conduct simulation tests on the two visual guiding schemes in curved tunnels with chevron alignment signs and retroreflective rings. The drivers’ curve illusion and reaction time

Common services tunnel is one of the successful applications for increase the resilience of urban utilities and infrastructure. In its isolated environment, the massive transport energy resources bring about a relatively high risk of thermal disaster. Characteristics of ceiling gas temperature is very important for early-phase detecting and controlling of the abnormal heat release. This paper presents

In the development of deep underground engineering operations, the surrounding rock is prone to large deformation, rockbursting, and other major engineering disasters. Pressure-relief blasting can improve the stress field in a deep rock mass and prevent the occurrence of roadway collapse. Based on the excavation of the Sandaoshan Mine, ANSYS/LS-DYNA dynamic finite element software is used to simulate

Among the parameters affecting the critical velocity in tunnel fires, the tunnel cross-sectional shape could significantly affect the tunnel fire characteristics, mainly due to the wall-bounded physics of the tunnel fire. Previously, the effects of the cross-sectional geometry of the tunnel were calculated using the non-dimensional analysis and hydraulic height of the tunnel. The dimensionless analysis

The integrity and stability of underground space mainly depend upon the coordination of primary and secondary support system. This paper presents a novel secondary standing support system, termed fibre-reinforced polymer (FRP)-confined high-water content cementitious grout material column (FCCM), being an alternative structural form for underground space. The attractive feature of the FCCM is its exterior

In tunnel fires, a hot gas propagates beneath a ceiling called the ceiling jet. The characteristics of the ceiling jet must be understood for safety and evacuation assessment. Small-scale experiments are useful to simulate the ceiling jet flow. The tunnel models used in previous studies have different dimensions (height and width) and wall thicknesses, and the walls were made of various materials.

Due to the complexities of design and technical issues of construction, tunnels are considered to be enormous financial investments. Therefore, rehabilitation with the purpose of providing a higher life span is essential. Underground facilities usually have a higher service period than expected when designed, which often requires regular inspection. This study aims at providing a guideline for future

Most studies concerning the evaluation of containment property for underground water-sealed oil storage caverns have focused on containment safety. However, the water inflow into storage caverns has not been considered. Too great of a water inflow into storage caverns leads to waste in water resources and increased cost of wastewater treatment. In this study, a quantitative index of containment efficiency

A test platform of the earth pressure balance shield is designed and manufactured. Taking a field project as the background, the test model with single cobble strata and two existing tunnels is planned, and the test of shield under-crossing the existing tunnels in the cobble strata is conducted. The surface settlement, the normal earth pressure acting on the existing tunnel, and the circumferential

Transport infrastructure, such as tunnels and underground structures, are usually built using reinforced concrete solutions. Since the 1970s, many transport structures (culverts, bridges, tunnels and animal crossings) have been made from corrugated steel plates and surrounding backfill (also known as soil-steel structures). These structures are a good alternative to reinforced concrete solutions because

Earth fissures, special engineering geological hazards, destroy the integrity of the ground and enlarge seismic responses of structures. Because of this, the safety of structures in the earth fissure environment is hard to guarantee, especially in bustling areas of the city in which underground stations and surface structures are affected by each other under earthquakes. In this paper, the 3D finite

In tunnel construction, shotcrete is sprayed on excavated surfaces to strengthen the walls and prevent rocks from falling off the tunnel face. Soon after, workers enter the face to erect the steel arch support. However, before entering, they must know the maximum rock size supported by the early-age shotcrete. This study aims to reveal the resistance and fracture mechanism of early-age shotcrete when

The numerical simulation of fires concerns an increasingly wide range of applications, among which archaeology. The Chauvet-Pont d’Arc Cave (France) presents thermal marks on some of its walls. These marks result from prehistorical fires and archaeologists would like to know their characteristics (fire location, mass of fuel, number of fires, etc) to make assumptions about their functions. Being impossible

This work explores the potential for predicting TBM performance using deep learning. It focuses on a 17.5-km-long tunnel excavated for the Yingsong Water Diversion Project in Northeastern China with its 728 days’ continuous monitoring of mechanical data. The prediction uses the deep belief network (DBN) proposed by Hinton et al. (2006),on the penetration rate, cutter rotation speed, torque, and thrust

The ground surfaces induced by the subway tunnel excavation has been an issue of great concern in the engineering field. When building subway tunnels in rugged mountainous cities, settlement problems are inevitable for shallow buried sections. Therefore, this paper analyzes the influence of some major tunnelling parameters on the surface settlement during excavation by creating a fine 3D FE model for

Deformations of tunnels and slopes are often induced by tunneling in landslide areas. However, the reinforcement measures for controlling slope deformation may be ineffective for preventing slope sliding, owing to the lack of a clear understanding regarding the slope failure and tunnel deformation modes. This study aimed to monitor the entire construction process of the Xiamaixi tunnel, to analyze

Underground structures in liquefiable saturated sand are prone to earthquake damage. Various simplified pseudo-static seismic response analysis methods for underground structures have been recommended by current design codes and guidelines, but lack adequate systematic validation in liquefiable ground. In this study, the effectiveness of four categories of simplified pseudo-static methods in saturated

During the near-seabed immersion stage, the submerged tunnel element suspended by immersion rigs and anchored to the seabed is at risk of possible bottom grounding and collision with the installed elements. Specifically, the wall effect would have an important role on the motion characteristics of the tunnel element when it approaches the seabed (The wall effect is the influencing behavior of one large

Numerical modeling of fault-slip rockbursts remains a great challenge due to the inherent difficulties in the simulation of fault slippage and rock failure under dynamic ground conditions. A sophisticated numerical method based on the distinct element method is proposed to simulate fault-slip rockbursts. The method successfully simulates the generation of a seismic event induced by fault slip. The

In this work, we investigate if, when, and how satellite InSAR can be used for evaluating surface settlements that occur during shield tunnelling in soft soil areas. We evaluate the applicability of InSAR prior, during, and after tunnel construction. Special emphasis is placed on the influence of the InSAR phase ambiguities in relation to short-term settlements that may occur during tunnel construction

This numerical study focused on the heat transfer process between the ultrafine water mist and explosion flame, and the suppression mechanism of ultrafine water mist and the effect of mist parameter on methane explosion. Hence, a three-dimensional numerical model for methane explosion suppression by ultrafine water mist was established. Large eddy simulation and partially premixed combustion models

To reveal the seismic response of underground structures in coral sand, a series of shaking table model tests on underground structures at four different groundwater levels were carried out. The seismic responses of the coral sand and the underground structure were obtained and analyzed. The results showed that the excess pore pressure ratio and the liquefaction degree of coral sand increased with

According to the equivalent design theory, the length of a tunnel model can be shortened by applying a resistance grid in a tunnel ventilation model experiment. To study the effect of a resistance grid on the ventilation model, this paper analyses the influence of the distance, number, and type of resistance grids in ventilation experiments via a series of model experiments and takes the Dabieshan

A new tunnel with closed portal has been constructed in the real project, most of current research on fire smoke movement are focus on traditional tunnel with two opening portals. In this paper, 44 numerical simulation tests were conducted in a 1:10 small scale model tunnel with different sealed situations, blockages and cross-sections. More specifically, two blockage ratios, width-blockage ratio β1

In past decades, impact hammers have played a key role in underground construction. Simply in Istanbul, impact hammers have been used to excavate more than 20 km of metro tunnels. Thus, determining the instantaneous breaking rate (IBR) of an impact hammer is attracting increasing attention. A number of IBR prediction models have been developed for impact hammers. However, there is still a demand for

Microtunnelling is an increasingly popular means of locating utilities below ground. The ability to predict the total jacking force requirements during a drive is highly desirable for anomaly detection, to ensure the available thrust is not exceeded, and to prevent damage to the pipe string and/or launch shaft. However, prediction of the total jacking force is complicated by site geology, the use of

Soft rock formations are widespread throughout the mountainous regions of the world including the mountains of western and southern Iran. Therefore, it is very common to pass through soft rock formations while building long tunnels for various purposes in the mountainous regions. The soft sedimentary rocks are frequently found in Zagros Mountains located in the south and west of Iran, where most of

Due to the influence of the rock mass structure, ground stress, groundwater conditions and construction process, the distribution of the strength and stress of surrounding rock in the soft rock tunnel is nonuniform. The supporting structure may undergo nonuniform deformation and local damage, which has a considerable impact on the safe construction of the tunnel. In this paper, two reference indexes

Shotcrete is often in direct contact with groundwater containing sulfate. The resistance to sulfate attack of modern sprayed concretes produced with non-alkali aluminate-based accelerators in combination with different cement types is related to their microstructure, transport properties, porosity and phase composition. A characterization of these properties allows a comprehensive assessment of the

Urbanization is an established trend worldwide. It generates negative consequences in urban areas threatening their sustainability and future. In this context, cities are utilizing their underground space at an accelerating rate. However, usually underground alternatives are only considered as a last resort. At the same time, the underground space is considered to have zero value and is not included

Site investigation plays a critical role in underground space development and geotechnical engineering practice, and it aims at collecting data for characterization of subsurface soil properties and stratification, which are often simplified as a two-dimensional (2D) vertical cross-section for subsequent geotechnical design and analysis in practice. In-situ tests, such as cone penetration tests (CPT)

To reveal the influence of an over-track-exhaust (OTE) system on particulate matter (PM) concentration and size distribution in underground stations, field measurements were performed at a subway station both in the tunnel ventilation and non-ventilation seasons. By regulating the operating conditions of the OTE system and analyzing different particle size ranges, the characteristics of PM concentration

Long-large subway tunnel accommodates the requirements of high-speed operation of trains, but also poses challenges on smoke control in case of tunnel fire. In conjunction with full-scale fire tests and theoretical analysis, this paper studies the fire behaviors of long-large subway tunnel by focusing on maximum ceiling smoke temperature rise, and smoke temperature rise distribution. The space downstream

In many studies, the face stability evaluations of underground excavations have been performed with an equal-area circular tunnel face instead of the real tunnel shape. This equivalent method greatly facilitates the model construction, but sacrifices the calculation accuracy. To solve this issue, a non-circular tunnel is studied here to assess its face stability by kinematical approach where the discretization-based

This 3D numerical study presents the factors affecting displacements and rotations induced by deep excavation in the vicinity of a tall building with an emphasis on the building parameters. An accurate model of a 31.2 m deep excavation with an adjacent 12-story building was used to validate the numerical modeling. Plane strain analysis of the excavation-induced deformations using building surcharge

Shield machine performance and tunnelling-induced settlement are the main concerns during the tunnelling process. This study proposes an artificial intelligence Internet of Things (AIoT)-based system for real-time monitoring of tunnel construction. Shield machine operational parameters and tunnelling-induced settlement can be transferred and stored in real time by an AIoT system. Thereafter, shield

In this study, a transient seismic structure-water-sediment-rock (SWSR) interaction model is proposed to evaluate seismic response of marine structure in ocean space under obliquely incident earthquake, in which the dynamic interaction between structure and its surrounding media, and wave radiation effect of truncated semi-infinite far field domain are fully considered. One particular advantage of

Moisture content contained in any dielectric media is the most influential factor reducing Ground Penetrating Radar (GPR) wave velocity, which can be measured by the gradients of diffractive hyperbolas as a result of any round-shaped object, such as water carrying utilities. Such characteristic were then used to estimate location of pipe leak where moisture content is higher in localized area compared

Fire is a major risk in urban underground utility tunnels. The fire and smoke spreading characteristics in natural gas cabins of urban underground utility tunnels are important for safety engineering. In this study, computational fluid dynamics (CFD) was used to investigate the fire and smoke spreading characteristics in natural gas cabins of urban underground utility tunnels, considering different

Accurate prediction of tunnel convergence is important to ensure the stability of tunnel structures. Reliability analysis of tunnel convergence on spatially variable soils was performed based on Monte Carlo simulations. The Young’s modulus of soils was shown to be spatially varied. The influence of the coefficient of variation, the vertical scale of fluctuation and the distribution type (i.e. beta

Traditional tunnel lighting luminance is calculated based on the designed hourly traffic volume and designed speed. This approach first determined the entrance section reduction factor and middle section’s luminance through the look-up table method, then calculated each section’s luminance in proportion. Since the designed value is often higher than the actual traffic flow value, and the calculated

The operating parameters of a tunnel boring machine (TBM) reflect its geological conditions and working status and are accordingly critical data for ensuring safe and efficient tunnel construction. The accurate prediction of the advance rate, rotation speed, thrust, and torque indicators based on the operating parameters can guide the control and application of a TBM. In this study, we analyzed the

Filling material is present around the segment lining when a shielded Tunnel Boring Machine is used to excavate a tunnel. The two-component grout is becoming lately one of the most used filling materials. Its mechanical properties evolve over time. Unfortunately, there are not many studies in the literature on the specific mechanical characteristics of these materials. This work presents the results

Underground mining has been plagued by gob fires triggered via self-igniting coal, the emission of toxic fumes, particulate matter, and possibly induced explosions from the gob fires make mining extremely dangerous. The spontaneous combustion of underground coal seriously affects the mining of adjacent coal seams and the overall safety production. The key to control the shallow coal seam fire is to

The instability of the tunnel face is one of the biggest concerns when tunneling with an earth pressure balanced shield (EPBS) machine. The mechanism by which the tunnel face fails is highly related to the advance status of the EPBS machine, which has rarely been studied. This paper aims to address this problem by examining the face stability in two situations, i.e., 1) EPBS machine advancement and

For ensuring safety during the construction and use of a super-large cross-section tunnel, it is essential to understand the lining structure failure pattern and the instability of the surrounding rock mass under a high burial depth. With the Letuan Tunnel of China as an engineering background, we conducted large-scale geo-mechanical model tests and numerical simulations in this study. The results

Underground transport infrastructure (tunnelling) plays a vital role to accommodate the rapid increase in urban population. Those tunnels are unavoidably constructed adjacent to high rising building supported by piled raft foundations which reduces differential settlements in the buildings. In this study, 3D numerical modelling using an advanced hypoplasticity soil model was carried out to investigate

Gas explosion accidents could lead to great losses of lives and property. Reliable prediction of structural responses under gas explosion loads is essential for developing effective technologies to mitigate the potential hazards of gas explosions. In the present study, numerical studies are conducted to investigate the performance of utility tunnels under gas explosion loads. Numerical models were

Changing burning area of spill fire may cause chain effects and expand consequences in tunnels, which poses a greater challenge to personnel escape and rescue. Research on tunnel spill fire is needed to reveal its behavior and internal mechanisms. This paper carried out a series of continuous spill fires on fireproof glass both in tunnel environment (TE) and open environment (OE). The spread, burning

Ground squeezing induced by tunnel excavation is a common phenomenon in weak and jointed rock masses. The prediction of convergence during tunnel construction in squeezing ground is important for the selection of temporary support and excavation methods. In the present study, the main factors that lead to ground squeezing are discussed based on a case study of the west section (WS) of the Tawarazaka

A fire outbreak in a urban tunnel with congested traffic may pose a great danger to all tunnel users. The main threat to human life in an urban tunnel fire is thick toxic smoke quickly filling large parts of the tunnel. It hinders evacuation and may even lead to lethal intoxication. Due to the potentially rapid development of the fire, people trapped will need to evacuate on their own. Thus, tunnel

There are no available guidelines or methodologies to design the concrete lining in a tunnel for loss of functionality following a fire event. Historical tunnel fires confirm that tunnel downtime following an extreme event can lead to major economic losses, while fire protection design of the concrete lining can be adjusted to minimize losses. This paper provides a framework to characterize fire damage

To investigate the characteristics of methane-air explosions in large-scale tunnels with different structures, the CFD code for gas explosion modelling of FLACS was validated and used to model the explosions in tunnelling faces, coalfaces and crosscuts, where explosions mostly occurred in coalmines. The maximum overpressures were obtained as about 150–1400 kPa but varied for places with different cross-sections