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3 pages, 165 KiB

Open AccessEditorial

Special Issue on Geotechnical Engineering Hazards

by Roohollah Kalatehjari

Appl. Sci. 2023, 13(8), 4923; https://doi.org/10.3390/app13084923 - 14 Apr 2023

Viewed by 1392

Abstract

Geotechnical engineering is a complex field that deals with various hazards that can impact soil, rock, and other geologic materials [...] Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

Research

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31 pages, 7146 KiB

Open AccessArticle

Analysis of Ground Motion Intensity Measures and Selection Techniques for Estimating Building Response

by Tariq A. Aquib, Jayalakshmi Sivasubramonian and P. Martin Mai

Appl. Sci. 2022, 12(23), 12089; https://doi.org/10.3390/app122312089 - 25 Nov 2022

Cited by 2 | Viewed by 2694

Abstract

The structural response of buildings to earthquake shaking is of critical importance for seismic design purposes. Research on the relationship between earthquake ground motion intensity, building response, and seismic risk is ongoing, but not yet fully conclusive. Often, probability demand models rely on [...] Read more.

The structural response of buildings to earthquake shaking is of critical importance for seismic design purposes. Research on the relationship between earthquake ground motion intensity, building response, and seismic risk is ongoing, but not yet fully conclusive. Often, probability demand models rely on one ground motion intensity measure (IM) to predict the engineering demand parameter (EDP). The engineering community has suggested several IMs to account for different ground motion characteristics, but there is no single optimal IM. For this study, we compile a comprehensive list of IMs and their characteristics to assist engineers in making an informed decision. We discuss the ground motion selection process used for dynamic analysis of structural systems. For illustration, we compute building responses of 2D frames with different natural period subjected to more than 3500 recorded earthquake ground motions. Using our analysis, we examine the effects of different structural characteristics and seismological parameters on EDP-IM relationships by applying multi-regression models and statistical inter-model comparisons. As such, our results support and augment previous studies and suggest further improvements on the relationship between EDP and IM in terms of efficiency and sufficiency. Finally, we provide guidance on future approaches to the selection of both optimal intensity measures and ground motions using newer techniques. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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16 pages, 4810 KiB

Open AccessArticle

A Critical Investigation on the Reliability, Availability, and Maintainability of EPB Machines: A Case Study

by Ali Koohsari, Roohollah Kalatehjari, Sayfoddin Moosazadeh, Mohsen Hajihassani and Bao Van

Appl. Sci. 2022, 12(21), 11245; https://doi.org/10.3390/app122111245 - 6 Nov 2022

Cited by 3 | Viewed by 1580

Abstract

Tunnelling is a vital geotechnical engineering feature of underground transportation systems that is potentially hazardous if not properly investigated, studied, planned, and executed. A reliability, availability, and maintainability (RAM) analysis is one of the main practical techniques in machinery-based projects to recognize the [...] Read more.

Tunnelling is a vital geotechnical engineering feature of underground transportation systems that is potentially hazardous if not properly investigated, studied, planned, and executed. A reliability, availability, and maintainability (RAM) analysis is one of the main practical techniques in machinery-based projects to recognize the failure and repair rates of machines during or after their operations. RAM analysis of mechanized tunneling can help to manage the project safety and cost, and improve the availability and performance of the machine. There are several methods to obtain and predict the RAM of a system, including the Markov chain simulation and other statistical methods; however, the result of the analysis can be affected by the selected method. This paper presents the results of a critical investigation on the RAM of the Earth pressure balance machines (EPBMs) used in developing an urban metro project in Isfahan, Iran. The five kilometer length of the first line of the Isfahan metro project was excavated using EPBMs over four years. After overhauling the EPBMs and making some minor changes, excavation of the second line started, and to date, about 1.2 km has been excavated by the refurbished machines. In the present study, a RAM analysis has been applied to electrical, mechanical, and cutter head subsystems of the EPBMs in Lines 1 and 2 of the Isfahan metro project over an 18- and 7-month period of machine operation, respectively. The results show that the estimated availability, A(t), determined by the Markov method, is closer to reality but cannot be propagated to reliability R(t) and maintainability M(t) analysis. It was also revealed that by predicting the required maintenance and proper planning, the overall availability of the EPBM was improved from 45% in Line 1 to 61% in Line 2. The outcomes of this study can be used in the future planning of urban tunneling projects to estimate machine, staff, and logistic performance with the least possible error, and appropriately arrange the factors involved in the system. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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26 pages, 18418 KiB

Open AccessArticle

Risk Coupling Analysis of Deep Foundation Pits Adjacent to Existing Underpass Tunnels Based on Dynamic Bayesian Network and N–K Model

by Jie Jiang, Guangyang Liu and Xiaoduo Ou

Appl. Sci. 2022, 12(20), 10467; https://doi.org/10.3390/app122010467 - 17 Oct 2022

Cited by 4 | Viewed by 1522

Abstract

Because deep foundation pits and tunnels are deformation-sensitive structures, the safety of these projects is generally affected by coupled risks. In deep foundation pit construction, if the existing tunnel structure adjacent to the deposit is damaged, it can produce a severe group disaster. [...] Read more.

Because deep foundation pits and tunnels are deformation-sensitive structures, the safety of these projects is generally affected by coupled risks. In deep foundation pit construction, if the existing tunnel structure adjacent to the deposit is damaged, it can produce a severe group disaster. It is necessary to identify an efficient risk analysis model to study the dynamic coupled risk of deep foundation pit projects adjacent to existing underpass tunnels and to analyze the risk evolution law to achieve effective real-time safety control. This study proposes a coupled risk analysis model using the N–K model and dynamic Bayesian network to construct deep foundation pits in adjacent existing underpass tunnels. The model is predicated on association rules to explore the interrelationship between risk factors to build a dynamic Bayesian network structure. In addition, the N–K model is utilized to quantify coupled risks under such complex working conditions and to optimize the dynamic Bayesian network structure. The developed model clarifies the risk coupling mechanism of deep foundation pit construction adjacent to an existing underpass tunnel, finds the critical points in the risk transfer process, and conducts dynamic risk prediction and accident causation diagnosis for the coupled risk to realize the dynamic control of the coupled risk in the adjacent existing underpass tunnel construction. Taking the Nanning underground comprehensive utilization project as an example, the validity and applicability of the proposed approach were tested. The results showed that the model is feasible and has application potential, providing effective decision support for safety control while constructing deep foundation pits adjacent to existing tunnels. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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19 pages, 8411 KiB

Open AccessArticle

Numerical Investigation on the Correspondence between the Damping and Coefficient of Restitution (COR) in Rockfall Movement

by Yan Ai, Hongyan Liu and Ziwei Ge

Appl. Sci. 2022, 12(20), 10388; https://doi.org/10.3390/app122010388 - 15 Oct 2022

Cited by 2 | Viewed by 1194

Abstract

The rockfall process is characterized by bounces of a block on the ground. The coefficient of restitution (COR), which indicates the degree of rockfall energy dissipation, has a significant effect on the rockfall trajectory. The 3-dimensional Distinct Element Code (3DEC) is an effective [...] Read more.

The rockfall process is characterized by bounces of a block on the ground. The coefficient of restitution (COR), which indicates the degree of rockfall energy dissipation, has a significant effect on the rockfall trajectory. The 3-dimensional Distinct Element Code (3DEC) is an effective tool to study the rockfall trajectory, and the damping can reflect the COR in numerical modeling. However, the relationship between damping and COR is not understood. A field test is numerically modelled to investigate the correspondence between damping and COR. A series of damping–COR correspondences are obtained and compared with the field test and its previous numerical simulation to verify the rationality of the correspondences. Then, the damping–COR correspondence is adopted in a typical rockslide in Yunnan province, China. The numerical results show that the proposed method is in good agreement with practical engineering. This study provides a new method for predicting rockfall trajectory. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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16 pages, 3579 KiB

Open AccessArticle

Experimental Study on Small-Strain Shear Modulus of Unsaturated Silty-Fine Sand

by Kai Yan, Yong Wang, Zhiyong Yang, Xianghua Lai and Cheng Chen

Appl. Sci. 2022, 12(17), 8743; https://doi.org/10.3390/app12178743 - 31 Aug 2022

Cited by 7 | Viewed by 1400

Abstract

The small-strain stiffness of soil is significant in the accurate prediction of the deformation caused by interactions between foundation soil and structures. Considering the whole range of small strain (10⁻⁶~10⁻³), a bending element-resonant column (BE-RC) combined test system was [...] Read more.

The small-strain stiffness of soil is significant in the accurate prediction of the deformation caused by interactions between foundation soil and structures. Considering the whole range of small strain (10⁻⁶~10⁻³), a bending element-resonant column (BE-RC) combined test system was developed to conduct continuous tests on the shear modulus of unsaturated soil. Under the dehydration path, it was used to investigate the small-strain shear modulus of unsaturated silty-fine sand in Hangzhou Bay, China. The results show that the shear modulus under different net stresses and matrix suctions appeared to non-linearly decay with the increase in strain until stable values were reached at a large strain. At the beginning from the saturated state, the G_max value increased slowly with decreasing saturation and reached its maximum value at the optimum saturation (S_r)_opt; then, it rapidly decayed to the level in the saturated, once the saturation degree decreased to a level lower than (S_r)_opt. Additionally, an improved prediction model was proposed for the G_max of unsaturated sand, considering different saturations. Based on the mesoscopic evolution of internal pore water morphology and the variation in intergranular stress caused by capillary action, the variation in the G_max could be divided into three segments of saturation: the boundary effect stage, the transition stage and the unsaturated residual stage. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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17 pages, 5662 KiB

Open AccessArticle

Seismic Liquefaction of Saturated Calcareous Sands: Dynamic Centrifuge Test and Numerical Simulation

by Weiqing Lyu, Yong Yuan, Pingshan Chen, Xiaocong Liang, Jiangxu Deng and Chong Li

Appl. Sci. 2022, 12(17), 8701; https://doi.org/10.3390/app12178701 - 30 Aug 2022

Cited by 2 | Viewed by 1205

Abstract

Both a dynamic centrifuge test and dynamic finite element analysis were carried out to assess the seismic liquefaction risk of a saturated-calcareous-sand site in a port project in Timor-Leste. Taking the in situ calcareous sands as the model material, two groups of horizontal [...] Read more.

Both a dynamic centrifuge test and dynamic finite element analysis were carried out to assess the seismic liquefaction risk of a saturated-calcareous-sand site in a port project in Timor-Leste. Taking the in situ calcareous sands as the model material, two groups of horizontal free-field model tests for medium dense and dense saturated calcareous sands were completed based on the two-stage scaling law theory. Three natural earthquake records with varied peak accelerations were adopted as input motions. The experimental results indicate that the shallower the depth, the lower the relative density, the longer the seismic duration, the larger the peak acceleration, and the more susceptible the saturated site to liquefaction. The sands on site at a depth of five to ten meters is highly risky for liquefaction with the excess pore pressure ratio reaching up to about 1.0 under the seismic peak acceleration of 0.3 g. The risk of liquefaction for site sands is rather small under the seismic peak acceleration of 0.1 g. The study reveals the characteristics of the pore pressure development in sites of varied relative densities under different seismic loadings, which provides a scientific basis for the liquefaction risk assessment of the engineering site. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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14 pages, 3683 KiB

Open AccessArticle

An Experimental Study for Swelling Effect on Repairing of Cracks in Fine-Grained Clayey Soils

by Mahdi Nikbakht, Fariba Behrooz Sarand, Arash Esmatkhah Irani, Masoud Hajialilue Bonab, Mohammad Azarafza and Reza Derakhshani

Appl. Sci. 2022, 12(17), 8596; https://doi.org/10.3390/app12178596 - 27 Aug 2022

Cited by 7 | Viewed by 1635

Abstract

Earth-dam failure starts with cracking in the clay core, and this cracking is not easy to detect and prevent. Therefore, swellable clay is a feasible solution, which helps to close the cracks automatically based on the self-healing process. The presented study utilizes experimental [...] Read more.

Earth-dam failure starts with cracking in the clay core, and this cracking is not easy to detect and prevent. Therefore, swellable clay is a feasible solution, which helps to close the cracks automatically based on the self-healing process. The presented study utilizes experimental procedures to analyze the swelling behavior of fine-grained clayey soils to prevent structural failure regarding crack generations. In this regard, the clayey materials were modified using Kaolin and Bentonite mixed with various weight percentages (2.5, 5.0, 7.5, 10.0, and 12.5%) and extracted the geotechnical characteristics of the studied soils, which included 90 specimens and 85 tests, such as physical properties, consolidation, particle-size analysis, hydrometry, Atterberg limits, compaction, odometer, and pinhole. The experimental results revealed that the swelling of the Bentonite is more than Kaolin satisfied for self-healing features in clayey soils. Regarding the numerous swelling tests, Bentonite provides optimum results (attained 10%) compared to Kaolin. As a verification procedure, the pinhole test was performed on samples, which revealed that Bentonite was dominant in controlling the water flow through the samples. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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11 pages, 1964 KiB

Open AccessArticle

Multi-Factor Influence Analysis on the Liquefaction Mitigation of Stone Columns Composite Foundation

by Pingshan Chen, Weiqing Lyu, Xiaocong Liang, Jiangxu Deng, Chong Li and Yong Yuan

Appl. Sci. 2022, 12(14), 7308; https://doi.org/10.3390/app12147308 - 20 Jul 2022

Cited by 7 | Viewed by 1485

Abstract

To optimize the design of stone columns composite foundation for liquefiable ground improvement in the Tibar Bay Port Project, a 3D Finite Element (FE) analysis is implemented on the earthquake response and liquefaction mitigation effect. Nine improvement schemes are designed with the orthogonal [...] Read more.

To optimize the design of stone columns composite foundation for liquefiable ground improvement in the Tibar Bay Port Project, a 3D Finite Element (FE) analysis is implemented on the earthquake response and liquefaction mitigation effect. Nine improvement schemes are designed with the orthogonal design method. Taking peak ground acceleration and peak excess pore pressure ratio as the target indicators, the influences of four factors, including diameter, replacement ratio, stiffness, permeability ratio, of stone columns are analyzed by means of range analysis, and subsequently, the optimal ground improvement design is obtained. The analysis results indicate that the responses of ground acceleration and excess pore pressure ratio are relatively sensitive to stone columns’ permeability ratio and a little sensitive to the replacement ratio. The stiffness and diameter ranging in the prescribed boundary only have negligible effect. The mitigation effect of drainage is rather significant when the ratio of the stone columns’ permeability to the soils’ permeability is greater than 100. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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11 pages, 4315 KiB

Open AccessArticle

Active Deformation Patterns in the Northern Birjand Mountains of the Sistan Suture Zone, Iran

by Maryam Ezati, Ebrahim Gholami, Seyed Morteza Mousavi, Ahmad Rashidi and Reza Derakhshani

Appl. Sci. 2022, 12(13), 6625; https://doi.org/10.3390/app12136625 - 30 Jun 2022

Cited by 10 | Viewed by 1637

Abstract

In this paper, faults, one of the most important causes of geohazards, were investigated from a kinematic and geometric viewpoint in the northern part of the Sistan suture zone (SSZ), which serves as the boundary between the Afghan and Lut blocks. Furthermore, field [...] Read more.

In this paper, faults, one of the most important causes of geohazards, were investigated from a kinematic and geometric viewpoint in the northern part of the Sistan suture zone (SSZ), which serves as the boundary between the Afghan and Lut blocks. Furthermore, field evidence was analyzed in order to assess the structural type and deformation mechanism of the research area. In the northern Birjand mountain range, several ~E–W striking faults cut through geological units; geometric and kinematic analyses of these faults indicate that almost all faults have main reverse components, which reveals the existing compressional stress in the study area. The northern Birjand mountain range is characterized by four main reverse faults with ~E–W striking: F1–F4. The F1 and F2 reverse faults have southward dips, while the F3 and F4 reverse faults have northward dips. Moreover, the lengths of the F1, F2, F3, and F4 faults are 31, 17, 8, and 38 km, respectively. These faults, with reverse components that have interactive relationships with each other, form high relief structures. The study area’s main reverse faults, including F1 to F4, are extensions of the Nehbandan fault system, while their kinematics and geometry in the northern Birjand mountain range point to an N–S pop-up structure. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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22 pages, 42266 KiB

Open AccessArticle

Landslide Susceptibility Assessment by Using Convolutional Neural Network

by Shahrzad Nikoobakht, Mohammad Azarafza, Haluk Akgün and Reza Derakhshani

Appl. Sci. 2022, 12(12), 5992; https://doi.org/10.3390/app12125992 - 13 Jun 2022

Cited by 56 | Viewed by 2700

Abstract

This study performs a GIS-based landslide susceptibility assessment using a convolutional neural network, CNN, in a study area of the Gorzineh-khil region, northeastern Iran. For this assessment, a 15-layered CNN was programmed in the Python high-level language for susceptibility mapping. In this regard, [...] Read more.

This study performs a GIS-based landslide susceptibility assessment using a convolutional neural network, CNN, in a study area of the Gorzineh-khil region, northeastern Iran. For this assessment, a 15-layered CNN was programmed in the Python high-level language for susceptibility mapping. In this regard, as far as the landside triggering factors are concerned, it was concluded that the geomorphologic/topographic parameters (i.e., slope curvature, topographical elevation, slope aspect, and weathering) and water condition parameters (hydrological gradient, drainage pattern, and flow gradient) are the main triggering factors. These factors provided the landside dataset, which was input to the CNN. We used 80% of the dataset for training and the remaining 20% for testing to prepare the landslide susceptibility map of the study area. In order to cross-validate the resulting map, a loss function, and common classifiers were considered: support vector machines, SVM, k-nearest neighbor, k-NN, and decision tree, DT. An evaluation of the results of the susceptibility assessment revealed that the CNN led the other classes in terms of 79.0% accuracy, 73.0% precision, 75.0% recall, and 77.0% f1-score, and, hence, provided better accuracy and the least computational error when compared to the other models. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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19 pages, 4990 KiB

Open AccessArticle

Coupled Numerical and Analytical Stability Analysis Charts for an Earth-Fill Dam under Rapid Drawdown Conditions

by Ali Azadi, Arash Esmatkhah Irani, Mohammad Azarafza, Masoud Hajialilue Bonab, Fariba Behrooz Sarand and Reza Derakhshani

Appl. Sci. 2022, 12(9), 4550; https://doi.org/10.3390/app12094550 - 30 Apr 2022

Cited by 13 | Viewed by 2395

Abstract

The presented article provides a comprehensive study on the stability analysis of earth-fill dams under rapid drawdown and transient flow conditions used to prepare stability analysis charts by conducting coupled finite-element numerical and analytical limit equilibrium procedures. In this regard, the impacts of [...] Read more.

The presented article provides a comprehensive study on the stability analysis of earth-fill dams under rapid drawdown and transient flow conditions used to prepare stability analysis charts by conducting coupled finite-element numerical and analytical limit equilibrium procedures. In this regard, the impacts of different rapid drawdown conditions on the safety factor of the Alavian earth-fill dam are determined. The slope stability charts present for both shallow and deep slip surfaces with various permeabilities are verified by ground information obtained with extensive instrumentation on the dam’s site. The results showed that by decreasing the permeability of the core’s material, despite preventing seepage, the instability risk of the upstream slope as a result of rapid drawdown intensifies. Also, as stability charts can be stated, with increasing the slip surface’s depth and decreasing the hydraulic hydration, the reliability decreases, and the sliding surfaces’ sensitivity increases based on the drawdown rates, which have been revealed to be from 0.2 to 0.6, the most critical state for safety factors, showing significant declines. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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18 pages, 11730 KiB

Open AccessArticle

Structural Characteristics and Formation Mechanism of the Earth Fissures as a Geohazard in Birjand, Iran

by Ahmad Rashidi, Mohammad Mahdi Khatib and Reza Derakhshani

Appl. Sci. 2022, 12(9), 4144; https://doi.org/10.3390/app12094144 - 20 Apr 2022

Cited by 12 | Viewed by 1681

Abstract

Earth fissure structures are a common type of geohazard associated with geotechnical surface ruptures that can occur almost anywhere on the ground surface due to a variety of different mechanisms, and in most cases, these hazardous cracks have resulted in severe damage to [...] Read more.

Earth fissure structures are a common type of geohazard associated with geotechnical surface ruptures that can occur almost anywhere on the ground surface due to a variety of different mechanisms, and in most cases, these hazardous cracks have resulted in severe damage to infrastructure. Investigation of the structural characteristics of fissures in an active tectonic area (such as Birjand in eastern Iran) can improve our understanding of connections between the fissures and structural geology. The first reported earth fissures in NW Birjand are distributed along the North Birjand fault. Field observations and analysis of the detailed topography cross-sections using the real-time kinematic (RTK) technique have been used to infer the fissure development. Morphometric analysis of faults and fissures shows that the long axis of most fissure structures is distributed perpendicular to the strike of the North Birjand fault. The average volume strain in the study area was calculated to be 14.68 percent based on fissure geometry studies, with the maximum volume strain corresponding to the location of the North Birjand fault’s youngest splay. This splay formed fault-propagation folds with exposed fissure structures. This study shows that the fault-propagation folds in this system are subjected to the activity and evolution of the ground fissure as a result of the expansion of tensile stress. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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31 pages, 4752 KiB

Open AccessFeature PaperArticle

Insights into Plugging of Pipe Piles Based on Pile Dimensions

by Antonio Kodsy and Magued Iskander

Appl. Sci. 2022, 12(5), 2711; https://doi.org/10.3390/app12052711 - 5 Mar 2022

Cited by 9 | Viewed by 3024

Abstract

Preliminary identification of plugging of open-ended pipe piles based on their dimensions, ahead of driving, is explored in this study using data analytics. Piles can be unplugged, plugged, or internally plugged, depending on their dimensions, and geotechnical conditions. Plugging of pipe piles influences [...] Read more.

Preliminary identification of plugging of open-ended pipe piles based on their dimensions, ahead of driving, is explored in this study using data analytics. Piles can be unplugged, plugged, or internally plugged, depending on their dimensions, and geotechnical conditions. Plugging of pipe piles influences both pile capacity and driving behavior; however, the classification assumed at the design time does not always manifest during driving, sometimes resulting in driving difficulties. The relationship between pile plugging and pile dimensions was investigated using a dataset of 74 load tests on pipe piles, where geotechnical profiles were also available. An analytics approach borrowed from data science was adopted. First, capacity was computed using four recognized designed methods considering the unplugged, plugged, and internally plugged conditions. Next, the calculated capacities were compared to capacities measured (interpreted) from static load tests. Finally, voting was employed to identify plugging based on the closeness of the computed capacity assumptions to the interpreted capacity. Most piles were found to be unplugged. A diameter criterion is proposed as a tool to give early insight into the plugging condition of a pile ahead of driving which resulted in a 70 ± 10% accuracy. The proposed criterion was validated once using a dataset of 23 piles with CPT data and a second time using 24 published driving records where plugging records were available and achieved similar accuracy, in both cases. It was concluded that piles larger than ~0.9 m (36 inches) in diameter have a higher likelihood of being unplugged, while piles smaller than 0.5 m (20 inches) have a higher likelihood of being plugged. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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22 pages, 12495 KiB

Open AccessArticle

Complex Variable Solution for Stress and Displacement of Layered Soil with Finite Thickness

by Xiangyu Sha, Aizhong Lu, Hui Cai and Chonglin Yin

Appl. Sci. 2022, 12(2), 766; https://doi.org/10.3390/app12020766 - 13 Jan 2022

Cited by 3 | Viewed by 1409

Abstract

The static problem of a layered isotropic elastic body is a very useful research subject in relation to the analysis and design of foundation works. Due to the complexity of the problem, there is no analytical solution to the problem so far. This [...] Read more.

The static problem of a layered isotropic elastic body is a very useful research subject in relation to the analysis and design of foundation works. Due to the complexity of the problem, there is no analytical solution to the problem so far. This study provides an efficient analytical approach to accurately calculate the displacement and stress fields of the soil. The constraints of bedrock on soil, different soil layer thickness and the shear stress of the foundation on soil were all taken into account in the analysis. In this study, each layer is regarded as an isotropic elastomer with infinite width, and the layers are in complete contact. By using conformal mapping, each layer is mapped to a unit circle, and the two complex potential functions are expanded into Taylor series with unknown coefficients. These unknown coefficients are obtained by satisfying boundary conditions and continuity conditions. The boundary and continuity conditions were verified in this paper. As a validation step, we compared the analytical results for the settlement with the results of the ANSYS numerical simulations and found good agreement. Parametric analyses were also carried out to investigate the influence of different distribution forms of base pressure on surface settlement, and the effects of layered properties on the surface settlement and stress field. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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24 pages, 9184 KiB

Open AccessArticle

Effects of Three-Directional Seismic Wave on Dynamic Response and Failure Behavior of High-Steep Rock Slide

by Ziwei Ge and Hongyan Liu

Appl. Sci. 2022, 12(1), 20; https://doi.org/10.3390/app12010020 - 21 Dec 2021

Cited by 3 | Viewed by 2449

Abstract

The landslide triggered by earthquakes can cause severe infrastructure losses or even fatalities. The high-steep rock slide is the most common type of landslide in the earthquake area. In an earthquake, the ground moves randomly in all directions, two horizontal directions (East-West (EW) [...] Read more.

The landslide triggered by earthquakes can cause severe infrastructure losses or even fatalities. The high-steep rock slide is the most common type of landslide in the earthquake area. In an earthquake, the ground moves randomly in all directions, two horizontal directions (East-West (EW) direction, North-South (NS) direction) and one vertical direction (Up-Down (UD) direction). Even though extensive studies have been carried out on the earthquake-triggered landslide, the effects of each single seismic wave and the three-directional seismic waves are not considered. This study aims to evaluate the effects of different types of the seismic waves on the dynamic response and failure behavior of the high-steep rock slide. To investigate the effects of each single seismic wave and three-directional seismic wave, this study presents a numerical model with four types of seismic waves, e.g., East-West (EW) direction, North-South (NS) direction, Up-Down (UD) direction, and three-directional wave (EW_NS_UD). The numerical results revealed that the types of the seismic waves have significantly different effects on the dynamic process, failure behavior, run-out distance, velocity, and deposition of the high-steep rock slide. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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13 pages, 1713 KiB

Open AccessFeature PaperArticle

Sand–Tire Shred Mixture Performance in Controlling Surface Explosion Hazards That Affect Underground Structures

by Hamed Dadkhah, Roohollah Kalatehjari, Mohsen Hajihassani, Mehdi Kharghani and Panagiotis G. Asteris

Appl. Sci. 2021, 11(24), 11741; https://doi.org/10.3390/app112411741 - 10 Dec 2021

Cited by 2 | Viewed by 2028

Abstract

Blasting is an unavoidable activity in geotechnical engineering, road and tunnel construction, and mining and quarrying. However, this activity can expose the environment to various hazards that are challenging to control and, at the same time, critical for the safety of site workers, [...] Read more.

Blasting is an unavoidable activity in geotechnical engineering, road and tunnel construction, and mining and quarrying. However, this activity can expose the environment to various hazards that are challenging to control and, at the same time, critical for the safety of site workers, equipment, and surrounding structures. This research aims to evaluate the ability of sand–tire shred mixtures to reduce peak blast pressure, which is the leading cause of damage to underground structures under surface explosion. ABAQUS software is used to model the material behavior under explosion and is validated using the results of previous studies and an empirical equation. Different scenarios are created by using mixture layers with different thicknesses (2, 4, and 6 m) and tire shred contents (10%, 20%, and 30%) that are subjected to various surface explosion charges (100, 500, 1000, and 5000 kg). The thickness of the mixture layer is found to be directly related to the dissipation of explosion energy. However, the percentage of the rubber content in the mixture is only significant in reducing peak blast pressure when a thick enough mixture layer is used. The results confirm the adequate performance of the correctly chosen sand–tire shred mixtures in reducing peak blast pressure and protecting the underground structure from surface explosion hazards. Full article

(This article belongs to the Special Issue Geotechnical Engineering Hazards)

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