Soil Dynamics and Earthquake Engineering最新文献

{"title":"Seismic characteristics of a high-steep slope with bedrock reinforced by the anchored sheet-pile wall and frame beam in shaking table tests","authors":"Haizhou Feng ,&nbsp;Guanlu Jiang ,&nbsp;Zilei He ,&nbsp;Shenxin Pan ,&nbsp;Shengyang Yuan ,&nbsp;Hongyu Chen","doi":"10.1016/j.soildyn.2025.109562","DOIUrl":"10.1016/j.soildyn.2025.109562","url":null,"abstract":"<div><div>The paper investigates the failure mode and reinforcement efficacy of a high-steep slope reinforced with anchored sheet-pile walls and frame beams (APFB). Two sets of shaking table tests were conducted on the natural and reinforcement slope. Considering post-rainfall earthquake conditions, the rainfall was applied first, followed by seismic loads. Acceleration amplification factor (AAF) and deformation of both slopes were analyzed. Additionally, the Fourier spectrum of slope accelerations were studied. The failure mechanism of both slopes was studied through shaking table tests and numerical simulation. The tests reveal a tension-shear failure mode for both slopes, characterized by three stages in the failure process: small deformation stage, local failure stage, and large deformation stage. Considerable deformation was observed in the section of slope above the upper part of both slopes, serving as the slide section and exhibiting tension failure. Conversely, the slope foot acts as the anti-slide section, exhibiting shear failure. The soil strength decreases as water content increases, leading to a higher likelihood of local failure during post-rainfall earthquakes. The AAF increases with seismic magnitude and frequency, exhibiting “height effect” and “surface effect”. The APFB attenuates high-frequency components of seismic loads, demonstrating a clear high-frequency filtering effect. Furthermore, the APFB restricts slope deformation and reduces seismic inertia effects, thereby enhancing overall slope stability.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"198 ","pages":"Article 109562"},"PeriodicalIF":4.2,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of ground motion characteristics in liquefaction triggering and lateral displacements of sloping grounds","authors":"Masoumeh Asgarpoor,&nbsp;Mahdi Taiebat","doi":"10.1016/j.soildyn.2025.109555","DOIUrl":"10.1016/j.soildyn.2025.109555","url":null,"abstract":"<div><div>This paper investigates the impact of ground motion characteristics on liquefaction triggering and liquefaction-induced response of sloping grounds, identifying the significance of each in predicting the system response. A three-stage harmonic waveform with varying peak ground acceleration (PGA), number of cycles at PGA (<span><math><msub><mrow><mi>N</mi></mrow><mrow><mtext>hold</mtext></mrow></msub></math></span>), and motion frequency (<span><math><mi>f</mi></math></span>) is applied at the base of mildly sloping soil columns, representing infinite sloping grounds. The soil columns are considered with different heights and slopes, each with different depth, thickness, and density of an embedded liquefiable layer. Fully coupled nonlinear dynamic analyses are conducted in OpenSees using the SANISAND-MSf v2 soil constitutive model, assessing the peak depth-averaged excess pore water pressure ratio in the liquefiable layer and the end-of-motion surface lateral displacement as engineering demand parameters (EDPs). Results show that increasing PGA enhances both EDPs, while distinct response patterns are observed at various motion frequencies, influenced by the natural frequency of the liquefied soil column. Higher <span><math><msub><mrow><mi>N</mi></mrow><mrow><mtext>hold</mtext></mrow></msub></math></span> increases excess pore water pressure generation and surface lateral displacements, as the soil remains in the post-liquefaction stage for a longer duration. An exploration of the relative significance of these characteristics on system responses reveals that PGA has a significantly greater contribution to the liquefaction triggering EDP compared to <span><math><mi>f</mi></math></span> and <span><math><msub><mrow><mi>N</mi></mrow><mrow><mtext>hold</mtext></mrow></msub></math></span>. For liquefaction-induced EDP, <span><math><mi>f</mi></math></span> is the most influential factor, followed by PGA and <span><math><msub><mrow><mi>N</mi></mrow><mrow><mtext>hold</mtext></mrow></msub></math></span>, which contribute similarly. These insights guide the selection of efficient intensity measures for predicting liquefaction triggering and liquefaction-induced response of sloping grounds.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"198 ","pages":"Article 109555"},"PeriodicalIF":4.2,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144297153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A probabilistic-statistical hybrid model for dominant pulses in pulse-like ground motions (PLGMs)","authors":"Yuhe Zou ,&nbsp;Xiaoyu Chen ,&nbsp;Dongsheng Wang ,&nbsp;Lei Tong ,&nbsp;Jiancheng Dai ,&nbsp;Weijian Tang","doi":"10.1016/j.soildyn.2025.109605","DOIUrl":"10.1016/j.soildyn.2025.109605","url":null,"abstract":"<div><div>Pulse-like ground motions (PLGMs) have been shown to significantly amplify the nonlinear seismic demands of structures, critically impacting seismic design and risk assessment. The effective simulation of pulse characteristics in PLGMs is essential for achieving these purposes. In this study, a probabilistic-statistical hybrid model optimized by genetic algorithms is proposed to efficiently simulate the dominant pulses of PLGMs. A comprehensive database consisting of 194 PLGMs from 36 global earthquakes was established, enabling detailed analysis of the correlations between the simulation model parameters and the real pulse in records. By utilizing Mavroeidis’ model, probabilistic-statistical models for the pulse period (<em>T</em>_p) and pulse amplitude (<em>V</em>_p), along with probabilistic distribution models for the wave shape parameter (<em>γ</em>) and phase parameter (<em>φ</em>), were systematically developed. This provides a comprehensive framework for characterizing pulses in PLGMs. Nonlinear structural analysis further demonstrates that the synthetic records generated by the proposed hybrid model effectively reproduce structural responses, enhancing their applicability in seismic design and risk assessment within engineering applications.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"198 ","pages":"Article 109605"},"PeriodicalIF":4.2,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144297007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic resilient modulus deterioration of Pisha sandstone filler under freeze-thaw cycles: Experimental and microstructural insights","authors":"Yixu Hu ,&nbsp;Xuesong Mao ,&nbsp;Qian Wu ,&nbsp;Peichen Cai ,&nbsp;Baolong Zhang ,&nbsp;Lunkun Chen","doi":"10.1016/j.soildyn.2025.109600","DOIUrl":"10.1016/j.soildyn.2025.109600","url":null,"abstract":"<div><div>The long-term mechanical stability of Pisha sandstone (PS) under freeze-thaw (FT) conditions and heavy loads remains insufficiently understood, significantly limiting its application in road engineering. To address this issue, a series of cyclic loading and microscopic tests were conducted on typical Pisha sandstone filler (PSF) from Ordos, Inner Mongolia, considering multiple influencing factors. These tests aimed to elucidate the degradation mechanism of its dynamic resilient modulus (<em>M</em>_R) under FT cycles in seasonally frozen regions. Additionally, a <em>M</em>_R prediction model was developed to account for the combined effects of heavy traffic loading and FT conditions. Furthermore, the microscopic damage mechanism of <em>M</em>_R deterioration was analyzed to provide a deeper understanding of the material's structural evolution under FT cycles. The results indicate that the <em>M</em>_R of PS increases significantly with rising confining pressure (<em>σ</em>₃) and cyclic dynamic stress (<em>σ</em>_d) and exhibits a monotonic increase with load frequency (<em>f</em>), particularly under high <em>σ</em>₃ and large <em>σ</em>_d. However, <em>M</em>_R gradually deteriorates with successive FT cycles, with the most severe damage occurring during the first cycle. The degradation process can be classified into three stages: rapid attenuation, slow attenuation, and stabilization. Additionally, <em>σ</em>_d and <em>f</em> are positively correlated with the damage factor (<em>D</em>_FT) and negatively correlated with the damage rate (<em>V</em>_FT). Microstructural analysis reveals a 47.73 % increase in porosity after the first FT cycle, leading to the fracture of cemented particles and the degradation of soil particle structure, thereby reducing <em>M</em>_R. After seven FT cycles, porosity increases by only 17.31 %, indicating that <em>M</em>_R stabilizes. This microstructural evolution closely aligns with the macroscopic degradation trend of <em>M</em>_R. Furthermore, based on the analysis of the influence of various factors, a predictive model for the <em>M</em>_R of PS under heavy loads and FT cycles was established, demonstrating high prediction accuracy. Finally, an internal mechanism explaining the strength degradation of PS under FT cycles was proposed, based on the evolution of its pore structure characteristics. The findings contribute to the sustainable design and optimization of PS subgrade in seasonally frozen regions, promoting its effective utilization as a reliable subgrade material.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"198 ","pages":"Article 109600"},"PeriodicalIF":4.2,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144288884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parametric study of tunnel fault resistance using numerical modeling and orthogonal experiment for segmental lining design","authors":"Qi Wang ,&nbsp;Yiying Chen ,&nbsp;Song Wang ,&nbsp;Ping Geng ,&nbsp;Peisong Li ,&nbsp;Huoming Shen ,&nbsp;Lin Deng","doi":"10.1016/j.soildyn.2025.109599","DOIUrl":"10.1016/j.soildyn.2025.109599","url":null,"abstract":"<div><div>Segmental linings can effectively mitigate tunnel damage caused by normal fault dislocation. To improve the tunnel's resistance to normal fault displacement, the fault resistance performance of segmental linings composed of conventional reinforced concrete segments and basalt fiber-filled concrete segments was investigated. A numerical model of the tunnel-surrounding rock system was established and verified for predicting deformation and damage evolution. Nine orthogonal experiments yielded a comprehensive six-indicator evaluation system for quantitatively assessing tunnel failure. Range analysis methodology was employed to quantify parameter sensitivity through calculation of damage index ranges across parameter levels. This systematically ranked the relative influence of: conventional segment length (6m, 9m, 12m), basalt fiber-filled segment length (0.4m, 0.6m 0.8m), and basalt fiber volume content (0.5 %, 0.4 %, 0.3 %) on the tunnel fault resistance. The results show that fiber-filled segmental linings perform well in most indicators. Shorter conventional reinforced concrete segmental length reduces plastic damage and enhance the tunnel's fault dislocation resistance. Basalt fiber-filled concrete accommodates larger fault displacements, reduces lining damage, and lowers the load utilization ratio. Increasing the fiber-filled segmental length reduces lining damage while decreasing the load utilization ratio, whereas narrowing it confines fault influence; thus, an optimal length balances these effects and modulates the load utilization ratio.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"198 ","pages":"Article 109599"},"PeriodicalIF":4.2,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinematic response of double-lined shafts embedded in homogeneous unsaturated soil subjected to P-wave excitation","authors":"Jiale Yang,&nbsp;Honggui Di,&nbsp;Shunhua Zhou,&nbsp;Guangbei Su,&nbsp;Chao He,&nbsp;Xiaohui Zhang","doi":"10.1016/j.soildyn.2025.109591","DOIUrl":"10.1016/j.soildyn.2025.109591","url":null,"abstract":"<div><div>This paper presents a novel mathematical model to investigate the kinematic response of a double-lined (DL) shaft embedded in homogeneous unsaturated soil subjected to vertically incident P-wave excitation, developed within the framework of elasto-dynamic continuum theory. The primary and secondary linings of the DL shaft are modeled as two parallel, linear elastic, undamped rods. The surrounding soil is treated as a three-phase (solid, liquid, and gas) porous viscoelastic medium, accounting for the compressibility of each constituent, the inertial and viscous coupling effects between the liquid and solid phases, and the saturation-dependent dynamic shear modulus. Closed-form series solutions for the kinematic response of the DL shaft are obtained based on the boundary conditions of the coupled DL shaft-unsaturated soil system. The accuracy of the proposed model is validated through comparison with existing solutions. The effects of key problem parameters, including soil saturation, depth-to-radius ratio, secondary lining thickness, and DL shaft-unsaturated soil modulus ratio, on the kinematic response factor and kinematic amplification factor are systematically evaluated. Additionally, equivalent static and kinematic Winkler moduli are theoretically derived for potential applications in further modeling. This study establishes a comprehensive analytical framework that advances the understanding of soil-DL shaft interaction in unsaturated ground and offers theoretical guidance for the seismic design of underground DL shafts.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"198 ","pages":"Article 109591"},"PeriodicalIF":4.2,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental determination of optimum tire chips-aggregates mixture in combi-grid encased granular piles in soft soil under cyclic loading","authors":"N. Muni Pradeep ,&nbsp;Suresh Kumar ,&nbsp;Sanjoli Gupta ,&nbsp;Mayank Nishant","doi":"10.1016/j.soildyn.2025.109598","DOIUrl":"10.1016/j.soildyn.2025.109598","url":null,"abstract":"<div><div>Soft soil subgrades often present significant geotechnical challenges under cyclic loading conditions associated with major infrastructure developments. Moreover, there has been a growing interest in employing various recycled tire derivatives in civil engineering projects in recent years. To address these challenges sustainably, this study investigates the performance of granular piles incorporating recycled tire chips as a partial replacement for conventional aggregates. The objective is to evaluate the cyclic behavior of these tire chip–aggregate mixtures and determining the optimum mix for enhancing soft soil performance. A series of laboratory-scale, stress-controlled cyclic loading tests were conducted on granular piles encased with combi-grid under end-bearing conditions. The granular piles were constructed using five volumetric proportions of (tire chips: aggregates) (%) of 0:100, 25:75, 50:50, 75:25, and 100:0. The tests were performed with a cyclic loading amplitude (<em>q</em>_<em>cy</em>) of 85 kPa and a frequency (<em>f</em>_<em>cy</em>) of 1 Hz. Key performance indicators such as normalized cyclic induced settlement (<em>S</em>_<em>c</em><em>/D</em>_<em>p</em>), normalized excess pore water pressure in soil bed (<em>P</em>_<em>exc</em>/<em>S</em>_<em>u</em>), and pile-soil stress distribution in terms of stress concentration ratio (<em>n</em>) were analyzed to assess the effectiveness of the different mixtures. Results indicate that the ordinary granular pile (OGP) with (25 % tire chips + 75 % aggregates) offers an optimal balance between performance and sustainability. This mixture reduced cyclic-induced settlement by 86.7 % compared to the OGP with (0 % TC + 100 % AG), with only marginal losses in performance (12.3 % increase in settlement and 2.8 % reduction in stress transfer efficiency). Additionally, the use of combi-grid encasement significantly improved the overall performance of all granular pile configurations, enhancing stress concentration and reducing both settlement and excess pore water pressure. These findings demonstrate the viability of using recycled tire chips as a sustainable alternative in granular piles, offering both environmental and engineering benefits for soft soil improvement under cyclic loading.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"198 ","pages":"Article 109598"},"PeriodicalIF":4.2,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144262237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Macro-micro mechanism of sand liquefaction under different waveforms via discrete element method (DEM)","authors":"Jiajin Zhao ,&nbsp;Zhehao Zhu ,&nbsp;Xiufeng Zhang","doi":"10.1016/j.soildyn.2025.109604","DOIUrl":"10.1016/j.soildyn.2025.109604","url":null,"abstract":"<div><div>Sand liquefaction is a critical geotechnical phenomenon in which saturated sand experiences a sudden loss of shear strength, resulting in various engineering failures. While past studies have extensively investigated liquefaction behaviour, the influence of waveform has received little attention. In particular, the connection between macroscopic mechanical behaviour and microscopic fabric evolution remains largely underexplored. To address this limitation, this study employed the Discrete Element Method (DEM) to simulate a series of undrained cyclic triaxial tests. The results revealed that rectangle waves caused the most severe liquefaction as a result of greater loading acting for a longer duration and produced unconventional liquefaction behaviours, as compared to sine and triangle waves. With coordination number (<em>C</em>_N) and the deviatoric part of the second invariant of the fabric tensor (<span><math><mrow><msub><mi>J</mi><mn>2</mn></msub></mrow></math></span>), this study demonstrates that both <em>C</em>_N and <span><math><mrow><msub><mi>J</mi><mn>2</mn></msub></mrow></math></span> can effectively capture the liquefaction process. However, <span><math><mrow><msub><mi>J</mi><mn>2</mn></msub></mrow></math></span> exhibited two distinct peaks at loading reversal points within the same cycle, expressing the inherent asymmetry in fabric anisotropy. A new indicator <span><math><mrow><msubsup><mi>J</mi><mn>2</mn><mi>R</mi></msubsup></mrow></math></span> was thus proposed to quantify the difference in peaks and a unified threshold value was identified, being a consistent marker for distinguishing liquefaction stages. Finally, a unified 3D liquefaction path was constructed integrating <span><math><mrow><msub><mi>J</mi><mn>2</mn></msub></mrow></math></span>, stress ratio (<span><math><mrow><mi>η</mi></mrow></math></span>), and shear strain (<span><math><mrow><msub><mi>ε</mi><mi>d</mi></msub></mrow></math></span>). This unified framework provides deeper insights into the interplay between macromechanical response and microscopic fabric, offering a comprehensive perspective on liquefaction mechanism.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"198 ","pages":"Article 109604"},"PeriodicalIF":4.2,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144262236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the effects of sand particle size on the liquefaction resistance of clean sands: An energy-based method","authors":"Mehrdad Biabani ,&nbsp;Jahangir Khazaei ,&nbsp;Yazdan Shams Maleki","doi":"10.1016/j.soildyn.2025.109571","DOIUrl":"10.1016/j.soildyn.2025.109571","url":null,"abstract":"<div><div>In this study, the liquefaction behavior of clean sand specimens is investigated in the framework of cyclic simple shear tests (CSSTs). The energy-based method (EBM) is the basis for presenting the results in this paper. The strain energy approach has been used to investigate the effects of changing the size of sand particles on its liquefaction resistance. The CSSTs have been performed under stress-controlled conditions on river sand at medium relative density (D_r = 52 %). The effects of changing the size of sand particles in CSSTs samples have been studied with the help of the mean particle diameter parameter D₅₀ in six different grain sizes. Until now, the effects of varying sand particle size, especially for samples with D₅₀ greater than 0.5 mm, on the cyclic liquefaction behavior of clean sands have been less systematically studied as a research gap using the elemental testing approach. The results of this study show that in a condition of the same relative density for sandy specimens with different particle sizes, an increase in the mean size of the particles along with changing the effective vertical stress on the samples causes a drastic decrease in the dissipated energy until the moment of liquefaction trigger of the specimens. For every 1137.30 % (11.37 times) increase in D₅₀ values (i.e., from 0.252 mm to 3.118 mm), an 88.89 % decrease (i.e., from 4.50 to 0.50 kJ/m³) occurs in the accumulative dissipated energy.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"198 ","pages":"Article 109571"},"PeriodicalIF":4.2,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144254271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reflection of SV wave at the free boundary of unsaturated soil","authors":"Luzhen Jiang ,&nbsp;Xin Zhang ,&nbsp;Junhai An ,&nbsp;Shuangfei Li","doi":"10.1016/j.soildyn.2025.109603","DOIUrl":"10.1016/j.soildyn.2025.109603","url":null,"abstract":"<div><div>The propagation mechanism of seismic waves in unsaturated soils and their impact on engineering structures constitute a fundamental research topic in geotechnical earthquake engineering. Conventional single-phase elastic models and two-phase saturated theories fail to accurately characterize the solid-liquid-gas coupling effects, while extended Biot theory-based models exhibit limited prediction accuracy due to insufficient consideration of fluid-solid inertial coupling. To address this issue, this study introduces a fluid additional mass density parameter to establish a more precise three-phase wave equation for unsaturated soils, systematically revealing the reflection and propagation mechanisms of SV waves at the free surface. Through rigorous mathematical derivation, complete analytical solutions including reflected SV, P₁, P₂, and P₃ waves are obtained, along with expressions for free-field displacement, velocity, acceleration, and stress components. Parametric numerical analysis is conducted to quantitatively investigate the influence of gas content on body wave reflection characteristics under varying saturation levels. The results demonstrate that: (1) The amplitude reflection coefficient of SV waves decreases with incident angle, whereas P₁, P₂, and P₃ waves display inverse proportionality; (2) At low saturation levels (Sr &lt; 0.9), the reflection coefficients of P₁ and P₂ waves exhibit minor variations, but increase significantly under high saturation levels (Sr ≥ 0.9); (3) The P₃ wave reflection coefficient exhibits positive incident angle dependence at low saturation levels, but diminishing to negligible magnitudes (1E-7) at high saturation levels; (4) Saturation variation has negligible effects on free-field displacement response. The proposed three-phase coupled wave theory model advances the quantitative characterization of wavefield energy distribution in multiphase media, providing a critical theoretical support for seismic response analysis of engineering sites and seismic design of underground structures.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"198 ","pages":"Article 109603"},"PeriodicalIF":4.2,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144261695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}