Pub Date : 2024-11-09DOI: 10.1016/j.enggeo.2024.107795
Xiaoqi Zhou, Peixin Shi
Subsurface stratification is crucial for the construction safety of underground projects. The one-dimensional (1D) soil stratification aims at identifying segmentation points that separate soil strata. Current engineering practice mainly requires human judgement, which is time-consuming, labour-intensive, and heavily relies on domain expertise. Other probabilistic methods, such as Bayesian approaches, usually involve complex expressions. With the advent of artificial intelligence, deep learning has emerged as a powerful tool in various domains. The UNet, as a typical convolutional neural network, has been extensively utilized for its superior performance in segmentation tasks, but struggles to capture global and long-range semantic information due to the locality of convolution operations. To realize intelligent and automatic 1D soil stratification, this paper introduces a UNet-like Transformer (ULTra) that integrates multiple data sources, including cone penetration test and borehole data, to incorporate prior knowledge. The architecture features a multi-level Transformer with shifted windows in both the encoder and decoder to extract context features and restore spatial resolution, respectively. Experimental results demonstrate that the ULTra outperforms other UNet variants, particularly in detecting minor textures and local details, underscoring the benefits of integrating Transformers into a standard UNet. Case studies indicate that compared with probabilistic methods, the ULTra enables automatic 1D soil stratification using original exploration data with less human intervention, which is fast, effective, and could be continuously improved through interaction with human knowledge, thus streamlining the intelligent data analysis.
{"title":"UNet-like transformer for 1D soil stratification using cone penetration test and borehole data","authors":"Xiaoqi Zhou, Peixin Shi","doi":"10.1016/j.enggeo.2024.107795","DOIUrl":"10.1016/j.enggeo.2024.107795","url":null,"abstract":"<div><div>Subsurface stratification is crucial for the construction safety of underground projects. The one-dimensional (1D) soil stratification aims at identifying segmentation points that separate soil strata. Current engineering practice mainly requires human judgement, which is time-consuming, labour-intensive, and heavily relies on domain expertise. Other probabilistic methods, such as Bayesian approaches, usually involve complex expressions. With the advent of artificial intelligence, deep learning has emerged as a powerful tool in various domains. The UNet, as a typical convolutional neural network, has been extensively utilized for its superior performance in segmentation tasks, but struggles to capture global and long-range semantic information due to the locality of convolution operations. To realize intelligent and automatic 1D soil stratification, this paper introduces a UNet-like Transformer (ULTra) that integrates multiple data sources, including cone penetration test and borehole data, to incorporate prior knowledge. The architecture features a multi-level Transformer with shifted windows in both the encoder and decoder to extract context features and restore spatial resolution, respectively. Experimental results demonstrate that the ULTra outperforms other UNet variants, particularly in detecting minor textures and local details, underscoring the benefits of integrating Transformers into a standard UNet. Case studies indicate that compared with probabilistic methods, the ULTra enables automatic 1D soil stratification using original exploration data with less human intervention, which is fast, effective, and could be continuously improved through interaction with human knowledge, thus streamlining the intelligent data analysis.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"343 ","pages":"Article 107795"},"PeriodicalIF":6.9,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.enggeo.2024.107790
Li Zhou , Yangshuai Zheng , Wei Hu , Yan Li , Hui Luo , Gonghui Wang
Fine particle loss in soil is one of the main causes of slope instability and geotechnical structure failure. Loss of fines can cause instability in granular assembles by changing the fabric and microstructure of the sample. However, real-time monitoring of the evolution of mechanical behavior in granular soils during the particle loss process is still poorly explored. This study presents a novel approach by simulating fine particle loss through salt dissolution in ring-shear tests, offering real-time insights into the mechanical evolution of granular soils under realistic stress conditions. Meanwhile, the shear resistance, shear displacement, vertical displacement, salt content, and acoustic emissions were simultaneously recorded. The test results showed that the instability of the sample was triggered by the loss of fine particles. With a gradual loss of fine particles, both the vertical and shear deformations and the void ratio increased. The evolution of shear resistance in the sample can be divided into three stages: stress weakening, then strengthening, and finally recovery to the initial value. We infer that the evolution of shear resistance originated from the collapse and rearrangement of its granular fabric and microstructure. Additional evidence for this hypothesis was provided by high-frequency acoustic emissions (approximately 150 kHz), suggesting buckling of the force chains accompanying the particle loss process. Furthermore, the sample experienced greater shear deformations and stress weakening that developed under a larger initial fine content or a higher normal stress. This finding may provide valuable insights into the mechanical behavior of granular soil during the fine particle loss process.
{"title":"Evolution of mechanical behavior in granular soil during fine particle loss simulated by salt dissolution: Insights from ring shear tests","authors":"Li Zhou , Yangshuai Zheng , Wei Hu , Yan Li , Hui Luo , Gonghui Wang","doi":"10.1016/j.enggeo.2024.107790","DOIUrl":"10.1016/j.enggeo.2024.107790","url":null,"abstract":"<div><div>Fine particle loss in soil is one of the main causes of slope instability and geotechnical structure failure. Loss of fines can cause instability in granular assembles by changing the fabric and microstructure of the sample. However, real-time monitoring of the evolution of mechanical behavior in granular soils during the particle loss process is still poorly explored. This study presents a novel approach by simulating fine particle loss through salt dissolution in ring-shear tests, offering real-time insights into the mechanical evolution of granular soils under realistic stress conditions. Meanwhile, the shear resistance, shear displacement, vertical displacement, salt content, and acoustic emissions were simultaneously recorded. The test results showed that the instability of the sample was triggered by the loss of fine particles. With a gradual loss of fine particles, both the vertical and shear deformations and the void ratio increased. The evolution of shear resistance in the sample can be divided into three stages: stress weakening, then strengthening, and finally recovery to the initial value. We infer that the evolution of shear resistance originated from the collapse and rearrangement of its granular fabric and microstructure. Additional evidence for this hypothesis was provided by high-frequency acoustic emissions (approximately 150 kHz), suggesting buckling of the force chains accompanying the particle loss process. Furthermore, the sample experienced greater shear deformations and stress weakening that developed under a larger initial fine content or a higher normal stress. This finding may provide valuable insights into the mechanical behavior of granular soil during the fine particle loss process.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"343 ","pages":"Article 107790"},"PeriodicalIF":6.9,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Correlation between soil compression index (Cc) and state parameters is frequently referenced in studies investigating the fundamental mechanisms underlying changes in soil compressibility. However, developing an efficient formula for Cc that adequately captures the complexity of soil compressive behavior has been challenging for conventional approaches. This study utilized contemporary symbolic regression (SR) to propose a generalized formula for Cc that can represent the nonlinear relationships with state parameters across various soil types. A geological database from southern Vietnam was utilized to establish this data-driven formula. Data exploration revealed the apparent combined effects of moisture content (w), initial void ratio (e0), and moist density (ρ) on soil compressive behavior. Statistical indicators and graphical analysis were adopted to comprehensively assess the performance of the proposed formula against empirical equations found in the literature, aiming to gain a deeper understanding of the mechanism influencing changes in soil compressibility. The evaluation results demonstrated the efficiency of the proposed formula in predicting Cc, as evidenced by low error metrics and a good balance between precision and accuracy. Moreover, the applicability and limitations of the proposed formula were examined using different regional soils with specified geologic origins. Given its reliability and adequacy, the proposed formula explicitly quantified the nonlinear combined effects of e0, ρ and w on the compressibility of undisturbed soils. However, further research accounting for clay minerals, specimen preparation, and geologic origins is needed to enhance the universal applicability of our understanding of soil compressive behavior.
在研究土壤压缩性变化的基本机制时,经常会提到土壤压缩指数(Cc)与状态参数之间的相关性。然而,对于传统方法而言,为 Cc 开发一个能充分捕捉土壤压缩行为复杂性的有效公式一直是个挑战。本研究利用当代符号回归法(SR)提出了一个通用的 Cc 公式,该公式可以表示各种土壤类型中与状态参数的非线性关系。越南南部的地质数据库被用来建立这个数据驱动的公式。数据探索显示了含水量(w)、初始空隙率(e0)和湿密度(ρ)对土壤压缩行为的明显综合影响。通过统计指标和图形分析,对照文献中的经验公式,全面评估了所提公式的性能,旨在深入了解土壤压缩性变化的影响机制。评估结果表明,所提公式预测 Cc 的效率较高,误差指标较低,精度和准确度之间的平衡较好。此外,还利用不同地区的特定地质成因土壤对所提公式的适用性和局限性进行了研究。鉴于其可靠性和充分性,所提出的公式明确量化了 e0、ρ 和 w 对未扰动土壤可压缩性的非线性综合影响。不过,还需要进一步研究粘土矿物、试样制备和地质起源,以提高我们对土壤压缩行为理解的普遍适用性。
{"title":"A generalized formula for predicting soil compression index using multi-evolutionary algorithm","authors":"Khanh Pham , Khiem Nguyen , Kyuhyeong Lim , Younseo Kim , Hangseok Choi","doi":"10.1016/j.enggeo.2024.107789","DOIUrl":"10.1016/j.enggeo.2024.107789","url":null,"abstract":"<div><div>Correlation between soil compression index (<em>C</em><sub><em>c</em></sub>) and state parameters is frequently referenced in studies investigating the fundamental mechanisms underlying changes in soil compressibility. However, developing an efficient formula for <em>C</em><sub><em>c</em></sub> that adequately captures the complexity of soil compressive behavior has been challenging for conventional approaches. This study utilized contemporary symbolic regression (SR) to propose a generalized formula for <em>C</em><sub><em>c</em></sub> that can represent the nonlinear relationships with state parameters across various soil types. A geological database from southern Vietnam was utilized to establish this data-driven formula. Data exploration revealed the apparent combined effects of moisture content (<em>w</em>), initial void ratio (<em>e</em><sub><em>0</em></sub>), and moist density (<em>ρ</em>) on soil compressive behavior. Statistical indicators and graphical analysis were adopted to comprehensively assess the performance of the proposed formula against empirical equations found in the literature, aiming to gain a deeper understanding of the mechanism influencing changes in soil compressibility. The evaluation results demonstrated the efficiency of the proposed formula in predicting <em>C</em><sub><em>c</em></sub>, as evidenced by low error metrics and a good balance between precision and accuracy. Moreover, the applicability and limitations of the proposed formula were examined using different regional soils with specified geologic origins. Given its reliability and adequacy, the proposed formula explicitly quantified the nonlinear combined effects of <em>e</em><sub><em>0</em></sub>, <em>ρ</em> and <em>w</em> on the compressibility of undisturbed soils. However, further research accounting for clay minerals, specimen preparation, and geologic origins is needed to enhance the universal applicability of our understanding of soil compressive behavior.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"343 ","pages":"Article 107789"},"PeriodicalIF":6.9,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1016/j.enggeo.2024.107784
Qin Chen , Qing-yang Zhu , Jun-lin Chen , Hai-bo Li , Xing-guo Yang , Jia-wen Zhou
Block theory is an important and commonly used method for addressing stability problems in rock engineering, and it is very meaningful to simplify its analysis procedure and improve its computational efficiency. In this paper, an improved vector method capable of simultaneously analyzing block removability and kinematics that works well for both convex and concave blocks is proposed. This improved approach is based on rigorously proven theorems. Compared to the original vector method in block theory, it is simpler and more efficient because it skips the removability analysis and simplifies some of the judgment conditions in kinematic analysis. With the results of kinematic analysis, the improved vector method can also determine the removability of the block. The validity of the improved vector method is verified by analyzing a series of individual convex or concave blocks with different removability and failure modes. Finally, the improved vector method is applied to the block progressive failure analysis of an engineering slope, which again validates the effectiveness of the improved vector method. The advantages of the improved vector method are highlighted through a comparison with existing methods, especially its high computational efficiency, ease of understanding and implementation.
{"title":"An improved vector method for simultaneous analysis of removability and kinematics in block theory","authors":"Qin Chen , Qing-yang Zhu , Jun-lin Chen , Hai-bo Li , Xing-guo Yang , Jia-wen Zhou","doi":"10.1016/j.enggeo.2024.107784","DOIUrl":"10.1016/j.enggeo.2024.107784","url":null,"abstract":"<div><div>Block theory is an important and commonly used method for addressing stability problems in rock engineering, and it is very meaningful to simplify its analysis procedure and improve its computational efficiency. In this paper, an improved vector method capable of simultaneously analyzing block removability and kinematics that works well for both convex and concave blocks is proposed. This improved approach is based on rigorously proven theorems. Compared to the original vector method in block theory, it is simpler and more efficient because it skips the removability analysis and simplifies some of the judgment conditions in kinematic analysis. With the results of kinematic analysis, the improved vector method can also determine the removability of the block. The validity of the improved vector method is verified by analyzing a series of individual convex or concave blocks with different removability and failure modes. Finally, the improved vector method is applied to the block progressive failure analysis of an engineering slope, which again validates the effectiveness of the improved vector method. The advantages of the improved vector method are highlighted through a comparison with existing methods, especially its high computational efficiency, ease of understanding and implementation.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"343 ","pages":"Article 107784"},"PeriodicalIF":6.9,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-06DOI: 10.1016/j.enggeo.2024.107785
Yajun Shi , Lianhai Zhang , Yanhu Mu , Wei Ma , Xiangbing Kong , Chengsong Yang
Freeze-thaw processes in cold regions alter soil pore structure and properties, leading to engineering geological issues. Soil pores are crucial, but research on their changes and freeze-thaw impacts is limited. This study used MRI-Cryogenic Soil Moisture Analyzer (MRI-CSMA) to explore pore structure, water, and temperature changes in saturated loess during freeze-thaw, and Scanning Electron Microscopy (SEM) to compare changes before and after. The results indicate that during the freezing process, the temperature in the frozen zone of the soil sample exhibited a staged change characterized by rapid cooling, transitional cooling, and stabilization at low temperatures, while the temperature decrease in the unfrozen zone showed no significant stages. Freeze-thaw action significantly affected the macropores and mesopores in the frozen zone, with an average increase of 15 % in macropores, a decrease of 16 % in mesopores, and minimal change in micropores (about a 1 % increase). In the unfrozen zone, there was a slight increase in micropores and mesopores (2 % and 3 %, respectively), and a 4 % decrease in macropores. Furthermore, during the freezing process, macropores in the unfrozen zone gradually decreased, while mesopores and micropores increased, leading to soil structure densification and promoting water migration towards the freezing front. This resulted in an initial increase followed by a decrease in water content near the freezing front during the early stages of freezing, confirming the view that pore structure compression drives water migration in the early stages of soil freezing. This study provides important insights for addressing engineering geological issues in cold regions under freeze-thaw conditions.
{"title":"Dynamic characteristics of soil pore structure and water-heat variations during freeze-thaw process","authors":"Yajun Shi , Lianhai Zhang , Yanhu Mu , Wei Ma , Xiangbing Kong , Chengsong Yang","doi":"10.1016/j.enggeo.2024.107785","DOIUrl":"10.1016/j.enggeo.2024.107785","url":null,"abstract":"<div><div>Freeze-thaw processes in cold regions alter soil pore structure and properties, leading to engineering geological issues. Soil pores are crucial, but research on their changes and freeze-thaw impacts is limited. This study used MRI-Cryogenic Soil Moisture Analyzer (MRI-CSMA) to explore pore structure, water, and temperature changes in saturated loess during freeze-thaw, and Scanning Electron Microscopy (SEM) to compare changes before and after. The results indicate that during the freezing process, the temperature in the frozen zone of the soil sample exhibited a staged change characterized by rapid cooling, transitional cooling, and stabilization at low temperatures, while the temperature decrease in the unfrozen zone showed no significant stages. Freeze-thaw action significantly affected the macropores and mesopores in the frozen zone, with an average increase of 15 % in macropores, a decrease of 16 % in mesopores, and minimal change in micropores (about a 1 % increase). In the unfrozen zone, there was a slight increase in micropores and mesopores (2 % and 3 %, respectively), and a 4 % decrease in macropores. Furthermore, during the freezing process, macropores in the unfrozen zone gradually decreased, while mesopores and micropores increased, leading to soil structure densification and promoting water migration towards the freezing front. This resulted in an initial increase followed by a decrease in water content near the freezing front during the early stages of freezing, confirming the view that pore structure compression drives water migration in the early stages of soil freezing. This study provides important insights for addressing engineering geological issues in cold regions under freeze-thaw conditions.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"343 ","pages":"Article 107785"},"PeriodicalIF":6.9,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-03DOI: 10.1016/j.enggeo.2024.107780
Jun Wang , Zhaomian Zhu , Zhiming Liu , Guangya Ding , Guohui Yuan , Xiaoyong Zhao
Sensor-enabled piezoelectric geocables were combined with a geogrid to acquire a sensor-enabled piezoelectric geogrid (SPGG) based on the impedance–strain relationship. Tension, pullout, and straight shear tests were conducted on this SPGG configuration. The tension test results indicated that the tensile strain–normalized impedance curves were exponential in form within the first 7 % of strain and the rate of shift in impedance was independent of the tension loading rate. An excellent correspondence between the peak strength and impedance inflection point was observed in the results of the pullout and straight shear tests. Additional validation of the proposed SPGG was conducted through a collapse test of the reinforced soil slope model. The results indicated that the SPGG-obtained strains were similar to actual strain gauge measurements but provided a larger measurement range and that the SPGG was able to sense real-time vibrations during the slope collapse using a voltage analysis, confirming that the proposed SPGG can simultaneously provide soil reinforcement, strain monitoring of reinforcement materials, and vibration sensing. This research is expected to inform the development of a dynamic and static monitoring, large range, and accurate method for monitoring the conditions of reinforced soil over their entire lifecycles.
{"title":"Indoor tests of sensor-enabled piezoelectric geocable–geogrid composite structure for slope rehabilitation and monitoring","authors":"Jun Wang , Zhaomian Zhu , Zhiming Liu , Guangya Ding , Guohui Yuan , Xiaoyong Zhao","doi":"10.1016/j.enggeo.2024.107780","DOIUrl":"10.1016/j.enggeo.2024.107780","url":null,"abstract":"<div><div>Sensor-enabled piezoelectric geocables were combined with a geogrid to acquire a sensor-enabled piezoelectric geogrid (SPGG) based on the impedance–strain relationship. Tension, pullout, and straight shear tests were conducted on this SPGG configuration. The tension test results indicated that the tensile strain–normalized impedance curves were exponential in form within the first 7 % of strain and the rate of shift in impedance was independent of the tension loading rate. An excellent correspondence between the peak strength and impedance inflection point was observed in the results of the pullout and straight shear tests. Additional validation of the proposed SPGG was conducted through a collapse test of the reinforced soil slope model. The results indicated that the SPGG-obtained strains were similar to actual strain gauge measurements but provided a larger measurement range and that the SPGG was able to sense real-time vibrations during the slope collapse using a voltage analysis, confirming that the proposed SPGG can simultaneously provide soil reinforcement, strain monitoring of reinforcement materials, and vibration sensing. This research is expected to inform the development of a dynamic and static monitoring, large range, and accurate method for monitoring the conditions of reinforced soil over their entire lifecycles.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"343 ","pages":"Article 107780"},"PeriodicalIF":6.9,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-03DOI: 10.1016/j.enggeo.2024.107776
María Magdalena Velázquez-Bucio , Maria Francesca Ferrario , Pierre Lacan , Eliana Muccignato , Marco Pizza , Aadityan Sridharan , Sabina Porfido , Sundararaman Gopalan , Andrés Nuñez-Meneses , Alessandro Maria Michetti
Most seismic risk assessments primarily focus on the impact of ground acceleration on infrastructure. However, in Mexico, along with numerous countries in Latin America and beyond, a significant portion of earthquake risk stems from secondary environmental effects such as tsunamis, landslides, and liquefaction processes. These secondary effects can often prove more lethal than the earthquake shaking itself. We used the Environmental Seismic Intensity scale (ESI-07) to assess the Earthquake Environmental Effects (EEEs) of the Mw 7.7 Michoacan earthquake on September 19th, 2022. This made it possible to comprehensively characterize the EEEs and their potential social consequences in the epicentral area along the Mexican subduction zone. Our study draws on data gathered from extensive field surveys, satellite imagery analysis, social media monitoring, and online resources, totalling data from over 8000 sites with EEEs. Through rigorous analysis, ESI-07 intensity values illuminate the vulnerability of coastal areas and coastal ranges to specific secondary effects triggered by large seismic events. We meticulously map the spatial distribution of these triggered EEEs, presenting A) an ESI-07 isoseismal map, and B) comparative analysis with other significant earthquakes, particularly subduction megathrust interface events. Our findings underscore the critical importance of considering environmental coseismic effects and using the ESI-07 scale in territorial planning and seismic risk preparedness. Furthermore, we highlight the unique characteristics of the Mexican Pacific coastal region and, more broadly, the distinct risks posed by coastal areas along subduction zones in terms of secondary seismic environmental hazards. This work emphasizes the urgent need to acknowledge the vulnerability of these regions to secondary effects and the imperative for resilience-building measures to safeguard human well-being and mitigate economic repercussions in the face of future seismic events.
{"title":"Environmental effects and ESI-07 intensity of the Mw 7.7, September 19th, 2022, Michoacán, Mexico, earthquake","authors":"María Magdalena Velázquez-Bucio , Maria Francesca Ferrario , Pierre Lacan , Eliana Muccignato , Marco Pizza , Aadityan Sridharan , Sabina Porfido , Sundararaman Gopalan , Andrés Nuñez-Meneses , Alessandro Maria Michetti","doi":"10.1016/j.enggeo.2024.107776","DOIUrl":"10.1016/j.enggeo.2024.107776","url":null,"abstract":"<div><div>Most seismic risk assessments primarily focus on the impact of ground acceleration on infrastructure. However, in Mexico, along with numerous countries in Latin America and beyond, a significant portion of earthquake risk stems from secondary environmental effects such as tsunamis, landslides, and liquefaction processes. These secondary effects can often prove more lethal than the earthquake shaking itself. We used the Environmental Seismic Intensity scale (ESI-07) to assess the Earthquake Environmental Effects (EEEs) of the M<sub>w</sub> 7.7 Michoacan earthquake on September 19th, 2022. This made it possible to comprehensively characterize the EEEs and their potential social consequences in the epicentral area along the Mexican subduction zone. Our study draws on data gathered from extensive field surveys, satellite imagery analysis, social media monitoring, and online resources, totalling data from over 8000 sites with EEEs. Through rigorous analysis, ESI-07 intensity values illuminate the vulnerability of coastal areas and coastal ranges to specific secondary effects triggered by large seismic events. We meticulously map the spatial distribution of these triggered EEEs, presenting A) an ESI-07 isoseismal map, and B) comparative analysis with other significant earthquakes, particularly subduction megathrust interface events. Our findings underscore the critical importance of considering environmental coseismic effects and using the ESI-07 scale in territorial planning and seismic risk preparedness. Furthermore, we highlight the unique characteristics of the Mexican Pacific coastal region and, more broadly, the distinct risks posed by coastal areas along subduction zones in terms of secondary seismic environmental hazards. This work emphasizes the urgent need to acknowledge the vulnerability of these regions to secondary effects and the imperative for resilience-building measures to safeguard human well-being and mitigate economic repercussions in the face of future seismic events.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"343 ","pages":"Article 107776"},"PeriodicalIF":6.9,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-03DOI: 10.1016/j.enggeo.2024.107783
Yu Zhao , Zhun Liu , Teng Liang , Fan He , Liangtong Zhan , Yunmin Chen , Daosheng Ling , Jing Wang
Naturally completely decomposed granite (CDG) soil typically exhibits strain-hardening behavior under undrained shear conditions. Nevertheless, flow-type landslides are not uncommon in CDG landfills. This paper endeavors to address the observed contradiction by conducting a case study of the 2015 Shenzhen landslides. Based on field investigations, we propose a hypothesis for the initiation and evolution of flow-type landslides in CDG landfill slopes, termed ‘clay particle argillization, mud-water migration, and static liquefaction’. This hypothesis was verified by element-scale internal erosion tests and triaxial tests, and further elucidated by microscale particle analysis. It was observed that the internal erosion-induced removal of plastic fine particles and retention of low-plasticity fine particles from CDG soil promotes the sliding and reorganization of coarse granules under shear stress, thereby increasing the soil's susceptibility to fluidization under undrained conditions. The proposed hypothesis and experimental findings provide new insights into the instability and subsequent extensive runout of CDG landfills and analogous broadly graded landslides.
{"title":"Soil fluidisation induced by fine particles migration: Insights from the Shenzhen 2015 landfill landslide","authors":"Yu Zhao , Zhun Liu , Teng Liang , Fan He , Liangtong Zhan , Yunmin Chen , Daosheng Ling , Jing Wang","doi":"10.1016/j.enggeo.2024.107783","DOIUrl":"10.1016/j.enggeo.2024.107783","url":null,"abstract":"<div><div>Naturally completely decomposed granite (CDG) soil typically exhibits strain-hardening behavior under undrained shear conditions. Nevertheless, flow-type landslides are not uncommon in CDG landfills. This paper endeavors to address the observed contradiction by conducting a case study of the 2015 Shenzhen landslides. Based on field investigations, we propose a hypothesis for the initiation and evolution of flow-type landslides in CDG landfill slopes, termed ‘clay particle argillization, mud-water migration, and static liquefaction’. This hypothesis was verified by element-scale internal erosion tests and triaxial tests, and further elucidated by microscale particle analysis. It was observed that the internal erosion-induced removal of plastic fine particles and retention of low-plasticity fine particles from CDG soil promotes the sliding and reorganization of coarse granules under shear stress, thereby increasing the soil's susceptibility to fluidization under undrained conditions. The proposed hypothesis and experimental findings provide new insights into the instability and subsequent extensive runout of CDG landfills and analogous broadly graded landslides.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"343 ","pages":"Article 107783"},"PeriodicalIF":6.9,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During the 2008 Wenchuan earthquake, extensive liquefaction of sand-like gravelly soil deposits was observed over an area of about 500 × 200 km2. Since gravel content significantly affects the stiffness and liquefaction resistance of gravelly soils, it has become an ongoing challenge for engineers to reliably and cost-effectively assess the liquefaction resistance of such soil deposits with different gravel contents. To this end, the procedures for consistently assessing the liquefaction resistance of sand-like gravelly soils were first put forward based on the previously proposed improved CRR-Vs1 characterization model for binary mixtures, which converts the liquefaction evaluation of sand-like gravelly soils into the assessment of liquefaction resistance of the base sand matrix with an equivalent stiffness. Then, in-situ gravelly soils sampled from the earthquake-impacted area were tested to parameterize the proposed characterization model. Lastly, liquefaction case histories of gravelly soils compiled during the 2008 Wenchuan earthquake were recompiled and restudied to validate the performance of the proposed characterization model. Typical liquefaction case history studies show that the proposed characterization model successfully predicts the severe liquefaction hazard at the Banqiao school site and the marginal liquefaction phenomenon at the Jiangyou thermal power plant site. Comparisons between the proposed characterization model and the 54 recompiled liquefaction case history datasets demonstrate that the proposed characterization model can accurately discriminate both the liquefied and non-liquefied case histories. These validation results in turn suggest that the proposed characterization model is highly feasible for engineering applications on a regional scale covering various gravel contents.
{"title":"Liquefaction evaluation on sand-like gravelly soil deposits based on field Vs measurements during the 2008 Wenchuan earthquake","authors":"Peng Xia , Yan-Guo Zhou , Yun-Min Chen , Yu-feng Gao","doi":"10.1016/j.enggeo.2024.107782","DOIUrl":"10.1016/j.enggeo.2024.107782","url":null,"abstract":"<div><div>During the 2008 Wenchuan earthquake, extensive liquefaction of sand-like gravelly soil deposits was observed over an area of about 500 × 200 km<sup>2</sup>. Since gravel content significantly affects the stiffness and liquefaction resistance of gravelly soils, it has become an ongoing challenge for engineers to reliably and cost-effectively assess the liquefaction resistance of such soil deposits with different gravel contents. To this end, the procedures for consistently assessing the liquefaction resistance of sand-like gravelly soils were first put forward based on the previously proposed improved <em>CRR</em>-<em>V</em><sub>s1</sub> characterization model for binary mixtures, which converts the liquefaction evaluation of sand-like gravelly soils into the assessment of liquefaction resistance of the base sand matrix with an equivalent stiffness. Then, in-situ gravelly soils sampled from the earthquake-impacted area were tested to parameterize the proposed characterization model. Lastly, liquefaction case histories of gravelly soils compiled during the 2008 Wenchuan earthquake were recompiled and restudied to validate the performance of the proposed characterization model. Typical liquefaction case history studies show that the proposed characterization model successfully predicts the severe liquefaction hazard at the Banqiao school site and the marginal liquefaction phenomenon at the Jiangyou thermal power plant site. Comparisons between the proposed characterization model and the 54 recompiled liquefaction case history datasets demonstrate that the proposed characterization model can accurately discriminate both the liquefied and non-liquefied case histories. These validation results in turn suggest that the proposed characterization model is highly feasible for engineering applications on a regional scale covering various gravel contents.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"343 ","pages":"Article 107782"},"PeriodicalIF":6.9,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-19DOI: 10.1016/j.enggeo.2023.107332
Weihang Chen , Jianwen Ding , Tengfei Wang , David P. Connolly , Xing Wan
Geotechnical testing serves to assess the strength and stiffness of in-situ soils, for purposes such as informing foundation design. Despite its importance, time constraints, financial considerations, and site-specific limitations often restrict testing to isolated locations with limited horizontal resolution. Therefore, this paper presents a novel hybrid generative deep learning model designed to approximate soil properties across sites based on sparsely sampled geotechnical data. The model uses geological subsurface samples derived from random field theory as ‘a priori’ data for a conditional variational auto-encoder (CVAE) model. By doing so, it attempts to map the relationship between in-situ data and the corresponding spatial coordinates, as well as the inherent link between in-situ data and spatial distribution. Then, in the post-processing phase, a Kriging model interpolates minor discrepancies between the measured and predicted values. To demonstrate its practical application, this paper focuses on cone penetration testing (CPT) as the geotechnical test method. The model's development is thoroughly discussed, followed by the validation using in-situ data and an analysis conducted with synthetic data. It is shown that the uncertainty associated with CVAE-Kriging depends upon both the distance from the sample point and the site's inherent complexity. The proposed methodology not only offers refined subsurface modeling but also expands the understanding of uncertainty in geotechnical testing. Practically, it can assist geotechnical engineers with insights during the survey phase.
{"title":"Soil property recovery from incomplete in-situ geotechnical test data using a hybrid deep generative framework","authors":"Weihang Chen , Jianwen Ding , Tengfei Wang , David P. Connolly , Xing Wan","doi":"10.1016/j.enggeo.2023.107332","DOIUrl":"https://doi.org/10.1016/j.enggeo.2023.107332","url":null,"abstract":"<div><p>Geotechnical testing serves to assess the strength and stiffness of in-situ soils, for purposes such as informing foundation design. Despite its importance, time constraints, financial considerations, and site-specific limitations often restrict testing to isolated locations with limited horizontal resolution. Therefore, this paper presents a novel hybrid generative deep learning model designed to approximate soil properties across sites based on sparsely sampled geotechnical data. The model uses geological subsurface samples derived from random field theory as ‘a priori’ data for a conditional variational auto-encoder (CVAE) model. By doing so, it attempts to map the relationship between in-situ data and the corresponding spatial coordinates, as well as the inherent link between in-situ data and spatial distribution. Then, in the post-processing phase, a Kriging model interpolates minor discrepancies between the measured and predicted values. To demonstrate its practical application, this paper focuses on cone penetration testing (CPT) as the geotechnical test method. The model's development is thoroughly discussed, followed by the validation using in-situ data and an analysis conducted with synthetic data. It is shown that the uncertainty associated with CVAE-Kriging depends upon both the distance from the sample point and the site's inherent complexity. The proposed methodology not only offers refined subsurface modeling but also expands the understanding of uncertainty in geotechnical testing. Practically, it can assist geotechnical engineers with insights during the survey phase.</p></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"326 ","pages":"Article 107332"},"PeriodicalIF":7.4,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49884970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}