Seismic ground response by twin lined tunnels with different cross sections

Panji, Mehdi; Mojtabazadeh-Hasanlouei, Saeed

doi:10.1007/s42452-021-04770-7

Cited by 14 publications

(3 citation statements)

References 80 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In researching the destruction of initial support structures in soft rock tunnels under high ground stress and large deformations, methods commonly used include theoretical analysis [9,10], numerical simulations [11], and field experiments [12,13]. Numerical simulations often employ finite difference methods [14], finite element analysis [11], and boundary element methods [15][16][17][18]. Scholars both domestically and internationally have found through theoretical analysis, numerical simulations, and field tests that the occurrence of large deformations in weak surrounding rock under high ground stress is directly related to geological conditions, original rock stress, and tunnel support methods.…”

Section: Introductionmentioning

confidence: 99%

Pressure-relief joints of initial support structural system used in tunnels with high-stress surrounding rock

Xu,

Bai

2024

PLoS ONE

View full text Add to dashboard Cite

To address the problem of large deformations in weak surrounding rock tunnels under high ground stress, which cause damage to initial support structures, this study proposes a novel type of circumferential pressure-relief joint based on the concept of relieving deformation pressure of the surrounding rock. Key parameters of the pressure-relief joint, such as initial bearing capacity peak, constant bearing capacity, and allowable pressure-relief displacement, were obtained through numerical simulations and laboratory experiments. A comparison was made between the mechanical characteristics of rigid joints and the new type of pressure-relief joint. The applicability of the pressure-relief joint was verified through field tests, monitoring the surrounding rock pressure, internal forces in the steel frames, and the convergence displacement of the support structure. The results show that: (1) In the elastic stage, the stiffness of the new pressure-relief joint is similar to that of rigid joints. In the plastic stage, rigid joints fail directly, whereas the pressure-relief joint can control deformation and effectively release the deformation pressure of the surrounding rock while providing a constant bearing capacity. (2) The right arch foot in the experiment had poor rock quality, leading to high stress in the steel frame and significant horizontal displacement. After the deformation of the pressure-relief joint, the stress in the surrounding rock and steel frame significantly reduced, and the rate of horizontal deformation of the support structure slowed down. (3) The vertical and horizontal final displacements of the pressure-relief joint in the experiment were 61mm and 15mm, respectively, which did not exceed the allowable deformation values. The components of the support structure remained intact, ensuring safety. However, this study has limitations: the design of the new pressure-relief joint only allows for a vertical deformation of 150mm and a horizontal deformation of 50mm, limiting the range of pressure-relief deformation.

show abstract

Section: Introductionmentioning

confidence: 99%

Pressure-relief joints of initial support structural system used in tunnels with high-stress surrounding rock

Xu,

Bai

2024

PLoS ONE

View full text Add to dashboard Cite

show abstract

“…They confirmed that cavities significantly influenced ground motion at high frequencies. In this context, many researchers have explored the cavity or tunnel effect on seismic ground response under body waves through various methods, such as analytical methods [8][9][10], numerical simulations [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26], and model tests [27][28][29][30]. Due to the complexity involved in wave propagation and limitations in modeling complicated systems of equations, numerical techniques are more effective compared to analytical and model tests for the parametric study of ground vibration problems [31].…”

Section: Introductionmentioning

confidence: 99%

A numerical study on effect of underground cavities on seismic ground response due to Rayleigh wave propagation

2023

View full text Add to dashboard Cite

Recent studies found that some structural damage can be attributed to the effect of surface waves. A shallow underground structure may be heavily influenced by surface waves, which makes to lose energy over distance more slowly than body waves. This study deals with evaluating the effect of Rayleigh waves (R-waves) interaction with underground cavities on the seismic ground response and amplification pattern using the Finite Element Method (FEM). First, the FEM model was verified to ensure its accuracy. Then, the influences of the effective parameters, such as cavity burial depth, distance from the cavity axis, and dimensionless incident frequency were investigated. Parametric studies revealed that the amplitude of ground motion is greater in the presence of a cavity with respect to that in the free-field condition. It was indicated that shallow cavities cause more amplification than cases with a larger depth ratio. By moving away from the wave source, the response of receiver points has a declining trend. Due to the complex interaction of R-waves with a cavity, the right side of the cavity has less amplitude than the left side. Finally, by increasing the dimensionless incident frequency, the distribution of the surface displacements and wave diffraction patterns gradually becomes more complicated while the peak displacement components decrease. Consequently, in light of the importance of the R-wave interaction with subsurface spaces, the findings of this study can help improve seismic design procedures and seismic microzonation guidelines.

show abstract

“…At present, relevant scholars have carried out a large number of dynamic response studies on the lining section form, tunnel depth, geological conditions, and other working conditions. Mehdi Panji et al [10] found that the enlargement of the horseshoe-shaped tunnel and the square tunnel is the largest. Concerning the buried depth of the tunnel, Jiang et al [11] proposed that the reasonable buried depth of the tunnel in the high-intensity seismic area should be no less than 50 m as far as possible according to the seismic acceleration response of mountain tunnels with different buried depths.…”

Section: Introductionmentioning

confidence: 99%

Shaking table tests of large cross-sectional multi-crack tunnel linings

You¹,

Gao²

2023

J. vibroeng.

View full text Add to dashboard Cite

To study the dynamic response law of large-section cracked lining structures under seismic waves, comparative tests of large-scale shaker tunnel models of non-destructive lining structure (model 1), a crack in the vault of the lining structure (model 2), and two parallel cracks in the vault of the lining structure (model 3) were carried out by applying 0.1-1.0 g progressively increasing the peak acceleration of the input waves. This paper visually showed the distribution of cracks in three groups of the lining structures. In addition, the acceleration response of the lining and surrounding rock, dynamic soil pressure, the dynamic strain on the inner and outer surfaces of the lining, and dynamic internal force variation were obtained, and the seismic performance of three groups of lining structures was discussed. The results showed that the seismic weak positions of model 1 were the arch shoulder and the arch foot, the seismic weak positions of model 2 were the arch shoulder, the arch foot, the initial damage area, and the inverted arch, and the seismic weak positions of model 3 were the positions of the arch foot, the cracks of the vault, the inverted arch, and the arch wall. The soil pressure values at the vault of three groups of models were model 2 > model 1 > model 3 in turn. The surrounding rock amplified the input seismic waves. With the gradual increase of the peak acceleration, the seismic energy was gradually consumed due to plastic damage to the lining structure or the loosening and destruction of the overlying soil, resulting in the acceleration amplification coefficient value of the surrounding rock in the upper part of the lining structure showing a changing trend of first increasing and then decreasing. When the peak acceleration was 0.2 g, the crack propagation phenomenon occurs in the initial crack position of model 2 and model 3. When the peak acceleration was 0.4 g, the cracking phenomenon occurs at the right arch foot of model 1. The above phenomenon confirmed the conclusion that cracks can weaken the seismic performance of the structure. When the peak acceleration was 0.8 g, the peak values of the amplification coefficient of the lining at the inverted arch and near the filled soil surface were about 1.2 and 1.6 respectively. The research results can provide a reference for the seismic performance evaluation of cracked tunnels.

show abstract

Seismic ground response by twin lined tunnels with different cross sections

Cited by 14 publications

References 80 publications

Pressure-relief joints of initial support structural system used in tunnels with high-stress surrounding rock

Pressure-relief joints of initial support structural system used in tunnels with high-stress surrounding rock

A numerical study on effect of underground cavities on seismic ground response due to Rayleigh wave propagation

Shaking table tests of large cross-sectional multi-crack tunnel linings

Contact Info

Product

Resources

About