Response Analysis Of Structures Research Articles

Experimental and Simulation Research on the Vibration Characteristics of the Traction Motor of Medium and Low Speed Maglev Train under Electromagnetic Excitation

In a medium and low speed maglev train, the linear induction motor (LIM) is employed as the traction motor, during operation its vibration characteristics correlate with the dynamic performance and noise radiation characteristics of the train. This paper conducted tests and established a three-dimensional simulation model of the LIM in a medium and low speed maglev train, to study the motor vibration characteristics by comparative analysis between test and simulation. The analysis results showed that the electromagnetic excitation sources of the train appear in the high-frequency band, with the main characteristic frequencies of 497.33 Hz, 994.33 Hz, 1989.00 Hz, and 3977.67 Hz. The structural modal analysis and vibration harmonic response analysis of the motor showed that the 3rd, 8th, and 18th modal frequencies of the motor structure approximate the frequencies of the electromagnetic excitation sources. As a result, the motor generates resonance at 497.33 Hz and 994.33 Hz under that excitation. The validity of the simulation was confirmed by the corresponding tests. From the perspective of theory, experiment, and simulation, this research can contribute to the optimization of traction systems in the future design of medium and low speed maglev trains.

A pyrolysis model for steel‐insulation sandwich building façade systems under fire

AbstractSandwich panels consist of two thin‐walled steel faces plus an insulation core. For this core, materials are selected that provide high (shear) stiffness and high thermal resistance. When the panels are subject to fire, the (a) temperature‐dependent behaviour of the steel faces and (b) the possible chemical reactions of the insulation core should both be considered, to accurately predict the structural behaviour. Provisions in Eurocode EN 1993‐1‐2 can be used for (a). Regarding (b), this paper adds a verified pyrolysis model to Heat Transfer (HT) analyses, and obtained results are transferred to a Structural Response (SR) analysis. Then, the HT and SR analyses are demonstrated in so‐called One‐Way Coupled (OWC) and Two‐Way Coupled (TWC) fire‐structure simulations, the latter including the effects of structural failure on the fire behaviour. For the cases studied, structural behaviour for OWC and TWC simulations is very similar, which indicates that the structural (failure) behaviour does not significantly influence the fire behaviour. Differently, the difference in failure time between simulations with and without pyrolysis is more than 15%, due to endothermic effects. As such, for the cases studied, modelling of pyrolysis is more important than the effect of structural failures, and this modelling can be included as demonstrated in this paper.

Convolutional neural network-based seismic fragility analysis of subway station structure considering spatial variation of site shear-wave velocity

Prior research demonstrated that the uncertainty of soil parameter can significantly impact the seismic response analysis and seismic performance evaluation of underground structures. To this end, the seismic response of a three-story, three-span subway station embedded in a typical layered engineering site was investigated in this study and the uncertainty of soil parameters was explicitly considered using the shear-wave velocity interlayer correlation model. In addition, an incremental dynamic analysis considering the uncertainty of the shear-wave velocity was performed using the one-dimensional convolutional neural network (1D-CNN) model as a surrogate model for the traditional finite element method. The results indicate that the uncertainty of soil shear-wave velocity increases the average PGA values for minor, moderate, and severe failures with a probability of exceeding 50% by about 10%, and increases the logarithmic standard deviation by about 40%. When considering the uncertainty of shear-wave velocity, the discreteness of the fragility curve will increase. Moreover, the rightward shift of the fragility curve midpoint leads to a comparatively more safety seismic performance evaluation of the structure under significant seismic input.

A new periodic seismic metamaterial with ultra-low bandgap for lamb waves

In this paper, we propose a new seismic metamaterial (SM) that can cover the main frequency range of earthquakes by introducing curved boundaries on a square cross-section and reducing the contact area between adjacent cells, which results in a wide bandgap at very low frequencies. The vibration modes at the edge of the first bandgap are analyzed, and the effects of the geometric and material parameters of the rubber on the first bandgap are studied. Meanwhile, vibration experiments are performed. Finally, finite structural dynamics response analysis is performed. The results show that the structure has excellent damping performance in low frequency band. At the same time, it can achieve effective attenuation for Oroville, Gilroy, and Corralitos earthquakes, which has potential applications in the field of seismic isolation and attenuation of buildings.

An extended two-scale random field model for stochastic response analysis and its application to RC Short-leg shear wall structure

For the stochastic response analysis of concrete structures, it is necessary to model the heterogeneous concrete with significant spatial variability by random fields. In practical applications, multiple material parameters are typically required to characterize the nonlinear constitutive relationship of concrete. As a result, the material parameters of concrete will be represented by a multivariate random field in the nonlinear stochastic response analysis. Nevertheless, a vast number of random variables are frequently involved in representing the multivariate random field, and it is difficult to quantify the probabilistic dependence among the material parameters. To address the preceding issues, this paper proposes an extended two-scale random field model (ETSRF) to quantify the spatial variability of the constitutive relationship of concrete. The model can accurately depict the fluctuation of material properties at the micro-meso scale and the spatial correlation at the macro scale. Besides, it is proved that there is a linear relationship between the mesoscopic random field and ETSRF. Furthermore, a new framework of stochastic response analysis is proposed, where the probability density evolution method (PDEM) is applied to obtain the probabilistic information of the structural responses, and ETSRF is adopted to describe the spatial variability of the material properties. Finally, the proposed model is validated by two illustrative examples, one of which simulates the random fields of compressive and tensile strength of a plain concrete slab, and the other of which deals with the stochastic response analysis of a RC short-leg shear wall structure. The results indicate that the proposed model can depict the spatial variability of the nonlinear constitutive relationship of concrete effectively.

Investigation on the dynamic bond-slip behaviour between steel bar and concrete

The bond behaviour between steel bar and concrete affects the response of reinforced concrete (RC) structures subjected to static and dynamic loads. Many studies have investigated the influencing factors on static bond behaviour between steel bar and concrete, e.g., cover depth to rebar diameter ratio (c/d) and concrete strength and various empirical formulae have been proposed to quantify the static bond strength, but the study of dynamic bond strength is very limited. As a result, in the analysis of dynamic structural responses, either perfect bond is assumed or static bond strength is adopted, which may lead to inaccurate structural response predictions. In this study, dynamic bond-slip behaviour between steel bar and concrete is numerically investigated by using the finite element (FE) model developed in LS-DYNA and verified against testing results. The effects of the concrete specimen shape, c/d ratio and concrete strength on the dynamic pull-out test are examined. It is found that the splitting of concrete dominates the failure mode of dynamic bond-slip behaviour. The ultimate bonding load is enhanced with the increase of loading rate. It is observed that the increase of bond strength relates to the dynamic increase factor (DIF) of concrete strength. The parametric studies show that among all considered factors, the shape of the pull-out test specimens has a minor effect on the ultimate bonding load, which on the other hand is highly dependent on the concrete strength and c/d ratio owing to the strain rate effect. An empirical relation of DIF of bond strength as a function of c/d ratio, concrete strength and strain rate is proposed based on the numerical results. A case study of drop weight test on an RC beam is then carried out to demonstrate the influence of considering the dynamic bond strength in numerical prediction of structural responses under dynamic loading.

Hazard‐consistent simulated earthquake ground motions for PBEE applications on stiff soil and rock sites

AbstractGround motion record selection is a standard step in state‐of‐the‐art performance‐based earthquake engineering (PBEE) applications. It links the structural response to seismic hazard of the site of interest. In this process, suites of hazard‐consistent ground motion recordings of a wide range of intensity levels are selected (and often scaled) from a database of ground motions to be used as input to nonlinear dynamic response analysis. The ideal practice would be to select ground motions from a database of recorded accelerograms in such a way that they are consistent with the seismic hazard at as many intensity measure (IM) levels as possible and for all important causative scenarios. However, the available databases are not heavily populated, especially for the large‐magnitude short‐distance scenarios. Therefore, synthetic ground motions are the natural candidates to enlarge the database of recordings for scenarios that are important to the site hazard but lack, completely or partially, recorded accelerograms. The usage of such recordings, however, can be recommended only after they are proven to be “realistic” through a battery of seismological and statistical tests. In this study, we propose and implement a multi‐fold testing framework for such an evaluation. We first generate a ground motion database of simulated ground motions (SDB) whose values of the parameters of the causative earthquakes are, to the extent possible, the same of those that caused the ground motions in a mirror database of recorded ground motions (RDB). We then utilize the conditional spectrum (CS) approach computed for a hypothetical rock site in Perugia, Italy, to select hazard consistent records separately from the RDB and SDB databases. A comprehensive set of comparisons of distributions of several IMs, computed from the selected sets, and of distributions of engineering demand parameters (EDPs), that such record sets induce on simple SDoF structures suggests the adequacy of using the proposed simulated ground motions for structural response analyses of structures on stiff and rock sites.

Effective-mode superposition response spectrum method for three dimensional seismic response analysis of underground structures

Response spectrum method (RSM) has been applied in seismic analysis of underground structures. However, the RSM is computationally low efficient for processing large soil domains. In this paper, the dynamic characteristics of underground structures are first investigated through three rectangular subway station structures. The results show that only a small number of effective frequencies and modes of soil-structure interaction (SSI) system significantly affect the seismic response of underground structure. These effective frequencies and modes are related to the natural vibration characteristics of site. An effective method is then developed to obtain the effective natural frequencies and modes of the SSI system. Subsequently, the effective modal superposition response spectrum method (ERSM) for seismic analysis of underground structure is developed by only combining the effective natural frequencies and modes of the SSI system to improve efficiency. Finally, the accuracy of ERSM is investigated through seismic response analysis of subway station structures. Numerical examples show that the ERSM can be used for seismic analysis of underground structures considering 3D SSI.

Simulation of a floating solar farm in waves with a novel sun-tracking system

The awareness of the energy and climate crisis has accelerated the development of renewable energy sources. Photovoltaic (PV) solar power plants harvest clean solar energy and convert it to electricity, which will be one of the most promising alternatives to the power industry in the context of a low-carbon society. Due to its low power density, the traditional deployment of PV systems on land or inland rivers requires much space. Therefore, industries are increasingly interested in expanding offshore Floating PhotoVoltaics (FPV) to oceans, where FPV has less influence on the marine environment and does not occupy precious space for land resources and human activities. This study performs a hydrodynamics-based structural response analysis for a novel FPV system in OpenFOAM. The wave-proof FPV platform is newly designed for this work, which integrated breakwater technologies to sustain the system’s survivability in harsh ocean-wave environments. Firstly, the rational mooring types for FPVs installed close to the island are studied considering seabed effects. Subsequently, extensive parametric studies have been conducted to determine a rational design strategy for the mitigation of wave impact. Several potential effects of the proposed platforms on the hydrodynamics in a coastal sea are evaluated for the first time.

STUDY ON EARTHQUAKE DESTRUCTION MODE OF THE LARGEST CANAL CROSSING HIGHWAY BRIDGE BASED ON IEM BOUNDARY IN SOUTH-TO-NORTH WATER DIVERSION

To study the dynamic failure mechanism and damage development law of highway bridge structure under the boundary effect in the process of seismic dynamic duration, the Wenchang Highway Bridge with the largest canal crossing in the South-to-North Water Diversion is taken as an example for seismic design analysis. Based on the finite element and infinite element coupling theory, the infinite element method boundary is introduced, the concrete damage plasticity is introduced, and the half-space free field model is established to study the energy dispersion phenomenon of waves in the boundary and the absorption effect of the infinite element method boundary on wave energy is verified. Under different peak acceleration intensities, the seismic response analysis of the bridge structure was carried out. The results show that: Under the action of selected artificial waves, the damage location of the bridge mainly concentrated in the junction of the box girder supported by the pier, the bottom of the pier and the junction of the pier and beam. The damage tends to develop downward near the bottom of the box girder. The damage at both ends of the beam extends from both ends to the middle. And the bottom and top of the pier have penetrating damage. These are weak points in seismic design. At a horizontal peak acceleration of 0.6g, in addition to damage to the pier column, damage also occurred to the bottom of the box girder. Therefore, when the horizontal peak acceleration of the seismic wave is greater than 0.6g, the failure of the bottom of the box girder is paid attention to. Moreover, the IEM boundary has a good control effect on the far-field energy dissipation of the wave, which is simpler and more efficient than the viscous–spring boundary.

Full-Scale Fire Resistance Testing and Two-Scale Simulations of Sandwich Panels with Connections

To understand sandwich panel behaviour under fire, expensive full-scale tests, or potentially more efficient fire-structure simulations can be carried out. However, these simulations have only been demonstrated to work for specific applications, either on the global scale (a fire on a simple panel) or on the small scale (a temperature load on a single screw connection), often loaded by a standard fire curve. In this paper, the quality of simulations for combined situations is investigated, i.e. a furnace fire on a set of panels including details and connections. First two existing tests are introduced, a sandwich panel façade test and a studs bolt test, followed by the presentation of their basic fire-structure simulations. In general, the heat transfer analyses agree well with the tests, whereas the structural response analyses need investigation: For the first test, out-of-plane deflections are overestimated at the beginning of the test. A parameter study indicates that this is most likely due to adhesive decomposition, resulting in face delamination and related instabilities. For the second test, the basic simulation does not show any failure, whereas the test failed by vertical bearing. However, with a two-scale model the ultimate load is estimated, and increasing vertical displacements and the onset of vertical bearing are predicted. It is concluded that future tests should include more simulation-relevant measurements. Also, global-scale models need to include features specific to the structure to be simulated, only known after tests and basic simulations, and connections may be decisive for global-scale behaviour, which can be incorporated by a two-scale model. Finally, the tests exhibited complex behaviour across different scales, and modifications and improvements of the simulations increased their fidelity. Therefore fire-structure simulations should always be verified with tests and compared with basic simulations, and modifications in the simulation models should be anticipated.

Wavelet packets-based simulation of non-stationary multivariate ground motions

This study proposes a novel approach to simulate non-stationary multivariate earthquake accelerograms for the seismic analysis of extended structures. This approach is based on an extension of the traditional stochastic decomposition technique applied to the wavelet packet theory using the spectral representation method. Using the advantages of a wavelet packet to identify the time and frequency characteristics of ground motion effectively, the generated recordings successfully reflected the non-stationarity in both the time and frequency domains. Accordingly, the spatial correlation trend was consistent with the selected coherence function. Compared to the ground motions observed using the traditional method, the proposed approach was exemplified by simulating ensembles of ground motions at three points spaced 200 m apart. The multivariate ground motions simulated by different methods were applied as multi-support excitations for the dynamic time–history analysis of a 190 m continuous rigid-frame box girder bridge. Notable variations in structural response were observed when considering the non-stationarity of the frequency domain, contrasting with the cases where it was not taken into account. This study provides an effective approach for generating non-stationary multivariate earthquake accelerograms, which is of great significance for structural response analysis in engineering applications.

Dynamic Response Analysis of Wind Turbine Structure to Turbulent Wind Load: Comparative Assessment in Time and Frequency Domains

This study investigates wind turbine structural dynamics using stochastic analysis and computational methods in both the time and frequency domains. Simulations and experiments are utilized to evaluate the dynamic response of a wind turbine structure to turbulent wind loads, with the aim of validating the results based on real wind farm conditions. Two approaches are employed to analyze the dynamic responses: the frequency domain modal analysis approach, which incorporates von Kármán spectra to represent the turbulent wind loads, and the time domain Monte Carlo simulation and Newmark methods, which generate wind loads and determine dynamic responses, respectively. The results indicate that, for a larger number of samples, both methods consistently yield simulated turbulent wind loads, dynamic responses and peak frequencies. These findings are further validated through experimental data. However, when dealing with a smaller number of samples, the time domain analysis produces distorted results, necessitating a larger number of samples to achieve accurate findings, while the frequency domain method maintains accuracy. Therefore, the accurate analysis of wind turbine structural dynamics can be achieved using simulations in both the time and frequency domains, considering the importance of the number of samples when choosing between time domain and frequency domain analyses. Taking these considerations into account allows for a more comprehensive and robust analysis, ultimately leading to more effective outcomes.

Optimum seismic design of frame structures with and without metallic yielding dampers considering life-cycle cost

This paper investigates the optimal design of steel moment-resisting frame (MRF) buildings, with and without metallic yielding dampers, using a life-cycle cost (LCC)-based optimal design process. The aim is to minimize the LCC as the design criterion, which includes construction cost and the loss of lifetime seismic consequences. The study employs the endurance time (ET) method for structural response analysis and the FEMA P-58 procedure for seismic loss assessment. Four design approaches are examined: (1) typical code-based design of an existing MRF without damper, (2) optimal LCC-based design of a new MRF without damper, (3) optimal LCC-based design of an existing MRF equipped with damper, and (4) optimal LCC-based design of a new MRF equipped with damper. In the third scenario, only the damper properties are optimized, whereas in the fourth scenario, both the frame and damper properties are optimized together. The main contribution of this study is the simultaneous comparison of the design outcomes from the four aforementioned design approaches. The results indicate that LCC-based re-designed structures can effectively reduce costs compared to code-based designs. The best results were achieved by incorporating metallic dampers. Moreover, incorporating dampers also reduced the construction cost for the LCC-based re-designed cases. Based on the results, when dealing with similar scenarios, adding dampers to an existing frame can be sufficient, eliminating the need to redesign both the damper and frame together.

Dynamic response analysis of spherical pressure hull implosion inside adjacent underwater structure

The implosion will occur when the pressure hulls have a geometric imperfection or are impacted from the outside, which could cause the collapse of submerged vessels. In this work, the open-source finite element solver OpenRadioss is used to analyze the implosion caused by the failure of the spherical pressure hull and the interference with the adjacent cylindrical shell in the double-hulled cabin of a submarine. Firstly, the implosions of the cylindrical tube and destruction of the spherical pressure hull are compared with experimental results. Secondly, the underwater implosion of the sphere is analyzed inside a cylinder with local impacts in different induced directions. The results found the flow field and structural deformation show obvious directivity, in which the deformations of the cylindrical shell are mainly caused by the absorption action instead of the shock wave effect when implosions occur in the direction closer to the cylinder. Finally, the dynamic responses of implosions are discussed under different triggering modes and hydrostatic pressures. We found that the structural deformation and energy evolution are similar when the sphere is subjected to a collapse load. However, the effect of triggering modes gradually becomes larger with the increase of hydrostatic pressure.

An efficient time-variant reliability analysis strategy embedding the NARX neural network of response characteristics prediction into probability density evolution method

Stochastic response analysis and first-passage reliability evaluation of multi-degree of freedom nonlinear systems subject to non-stationary seismic excitation have been a critical issue in the field of compound random vibrations, yet remain unsolved. This study extends the time-varying reliability analysis method based on the probability density evolution method, making it applicable to the problem of stochastic response analysis and first-passage reliability evaluation of complex engineering structures. To efficiently represent the response of representative samples, a nonlinear autoregressive with exogenous inputs neural network model is introduced in this study. After comparing three different optimization methods, the neural network model based on the Bayesian regularization algorithm is selected as the predictor for the response of complex nonlinear systems, enabling efficient stochastic response analysis and time-varying reliability evaluation. To this end, leveraging the high efficiency of the probability density evolution method, the analysis of time-varying reliability of large-scale structures has been successfully conducted. Furthermore, the proposed method can be easily expanded to dynamic reliability evaluation problems represented by extreme value theory. Three numerical examples are quoted to demonstrate the applicability and advantages of the proposed method in the field of first-passage and extreme-value problems of systems, which are also compared with PCE, SVR, and Kriging. The results from these numerical examples indicate that the proposed method can effectively reduce the required calculational cost for the reliability analysis of complex structures while maintaining high analytical accuracy.

Reliability Evaluation of a Nonlinear Frame Structure under Explosive Ground Motions Generated by Dimension-Reduction Method

In the present study, a stochastic model of explosive ground motions applying the dimension-reduction method is proposed, and the reliability evaluation of a nonlinear frame structure under such excitations is realized by means of the probability density evolution method and an equivalent extreme-value-based reliability evaluation strategy. Firstly, the evolutionary power spectrum density function of the explosive ground motions is modeled by respectively identifying the normalized total energy distribution function and the frequency total energy distribution function on the basis of the measured motion records. In addition, an exponential model is constructed to forecast the seismic characteristics of the explosive ground motions based on the given distance to the explosive source and the charge quantity. Then, the representative samples of the explosive ground motions are simulated using the dimension-reduction method. The simulation results show that the generated acceleration samples have significant seismic characteristics of the explosive ground motions, and the accuracy is verified by comparing the second-order statistics with the sample set and the corresponding targets. Due to the fact that the probabilities of the representative samples simulated by the dimension-reduction method can compose a comprehensive probability set, it contributes to the refined dynamic response analysis and reliability evaluation of complex structures combining with the probability density evolution method. The accurate dynamic response analysis and reliability evaluation of a nonlinear frame structure illustrates the effectiveness of the proposed model and the dimension-reduction method for simulating the explosive ground motions. The numerical results demonstrate that the explosive ground motions have a substantial effect on the nonlinear behavior and the security of engineering structures.

Adaptive linear quadratic regulator for optimal structural control based on wavelet transform and genetic algorithm

PurposeIn real life, excitations are highly non-stationary in frequency and amplitude, which easily induces resonant vibration to structural responses. Conventional control algorithms in this case cannot guarantee cost-effective control effort and efficient structural response alleviation. To this end, this paper proposes a novel adaptive linear quadratic regulator (LQR) by integrating wavelet transform and genetic algorithm (GA).Design/methodology/approachIn each time interval, multiresolution analysis of real-time structural responses returns filtered time signals dominated by different frequency bands. Minimization of cost function in each frequency band obtains control law and gain matrix that depend on temporal-frequency band, so suppressing resonance-induced filtered response signal can be directly achieved by regulating gain matrix in the temporal-frequency band, leading to emphasizing cost-function weights on control and state. To efficiently subdivide gain matrices in resonant and normal frequency bands, the cost-function weights are optimized by a developed procedure associated to genetic algorithm. Single-degree-of-freedom (SDOF) and multi-degree-of-freedom (MDOF) structures subjected to near- and far-fault ground motions are studied.FindingsResonant band requires a larger control force than non-resonant band to decay resonance-induced peak responses. The time-varying cost-function weights generate control force more cost-effective than time-invariant ones. The scheme outperforms existing control algorithms and attains the trade-off between response suppression and control force under non-stationary excitations.Originality/valueProposed control law allocates control force amounts depending upon resonant or non-resonant band in each time interval. Cost-function weights and wavelet decomposition level are formulated in an elegant manner. Genetic algorithm-based optimization cost-efficiently results in minimizing structural responses.

Structural response analysis of free rigid-perfectly plastic warhead under three typical transverse loads

Based on the rigid-perfectly plastic assumption, the structural response of a free warhead under the application of concentrated force, evenly distributed force, and ramping-up force was analysed, taking the geometrical features into account. By the sectional shear force and bending moment distribution, the critical section was determined through a yield criterion based on the fully plastic bending moment. It shows that when the load is applied at the tip of the warhead, singularity occurs in the yield function at the tip, but vanishes when the applying (or starting) point of the load some distance away. The influence of the distance of the applying (or starting) point to the tip was also discussed, and was found to be important in determining the location of the critical section. As the applying (or starting) point moves away from the tip, the critical section appears near the tip first, then jumps to the cylinder part of the warhead, and when far enough, jumps back to the head of the warhead in the concentrated force case, while in the distributed force cases the critical section appears first at the cylinder part, and then jumps to the head. The critical section jumps to the head much earlier and more localized around the connecting point of the head and the cylinder in the ramping-up case than in the evenly distributed case.

Numerical prediction of ground vibrations induced by LPG boiling liquid expansion vapour explosion (BLEVE) inside a road tunnel

Accidental boiling liquid expansion vapour explosions (BLEVEs) caused by the bursting of liquified petroleum gas (LPG) tank inside a tunnel can induce vibrations of its surrounding geological media and threaten the stability of adjacent tunnels and structures. Therefore, it is essential to understand the characteristics of vibrations induced by LPG BLEVEs inside the tunnel for the safety design of its adjacent structures. Owing to the difficulty in effectively predicting the LPG BLEVE loads, the current practice usually employs equivalent methods, e.g., the TNT-equivalency method, in LPG BLEVE load predictions for structural response analysis, which may lead to inaccurate response predictions. This study compares ground vibrations induced by a BLEVE inside an arched road tunnel with those induced by its equivalent TNT explosion via high-fidelity numerical simulations. The results demonstrate that the frequency of BLEVE-induced vibrations is lower than that induced by the TNT explosion at the same scaled distance. The intensity of LPG BLEVE-induced vibrations at relatively small-scaled distances is lower than that of TNT explosion-induced vibrations at the same scaled distance, but becomes higher after a certain scaled distance because of the relatively low attenuation rate. In addition, parametric analysis is conducted to evaluate the effects of various factors on the characteristics of LPG BLEVE-induced ground vibrations. It is found that the surrounding rock type, the rock porosity, and the cover depth of the tunnel have more significant influences than the concrete grade of the tunnel lining. The recommendation for the tunnel design is also given based on the intensity and frequency characteristics of BLEVE-induced vibrations.