Geomechanics for Energy and the Environment最新文献

英文中文

A novel analytical approach for evaluating thermally active underground retaining walls 一种新的热活动地下挡土墙评价分析方法

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2026-03-01 Epub Date: 2026-02-26 DOI: 10.1016/j.gete.2026.100812

Aakash Gupta , Fleur Loveridge , Ida Shafagh , Simon J. Rees

Shallow geothermal energy is a promising renewable technology for sustainable indoor heating and cooling. One method to exploit this energy is through Energy Geostructures, where structural elements embedded in the ground are thermally activated via heat exchange pipes embedded within the structure. These structures function as a specialised form of ground heat exchanger, which can be integrated with ground source heat pump systems. Energy walls (EWs), a specific type of Energy Geostructure, are commonly used in basements, underground parking facilities, and metro stations. Despite their potential, there is currently no simple and reliable analytical method for the thermal analysis of EWs. Instead, their design relies on computationally expensive numerical simulations or oversimplified 'rules of thumb', both of which may lead to inefficiencies in cost and performance. This study presents a novel analytical approach based on the Infinite Plane Source (IPS) model and evaluates its accuracy by comparing it with two-dimensional numerical model data. The results demonstrate that the proposed method provides highly accurate estimates of temperatures at the back of the wall, making it a valuable foundation for future analytical design methodologies. The findings are applicable to EWs having an excavation on one side and ground on the other, as well as fully buried EWs with soil on both sides. This research offers a significant step toward the development of a practical, cost-effective analytical framework for the design and optimisation of EWs, promoting the broader adoption of shallow geothermal energy systems.

浅层地热能是一种很有前途的可再生室内供暖和制冷技术。利用这种能量的一种方法是通过能源土工结构，其中嵌入在地下的结构元件通过嵌入在结构中的热交换管进行热激活。这些结构作为一种特殊形式的地热交换器，可以与地源热泵系统集成。能源墙（Energy walls, EWs）是一种特殊类型的能源土工结构，通常用于地下室、地下停车场和地铁站。尽管其潜力巨大，但目前还没有简单可靠的分析方法来分析电炉的热分析。相反，它们的设计依赖于计算成本高昂的数值模拟或过于简化的“经验法则”，这两种方法都可能导致成本和性能的低效率。本文提出了一种新的基于无限平面源（IPS）模型的解析方法，并通过与二维数值模型数据的比较，对其精度进行了评价。结果表明，所提出的方法提供了高度准确的估计在墙后的温度，使其成为未来的分析设计方法的宝贵基础。研究结果适用于一侧为开挖而另一侧为地面的ewws，以及两侧为全埋且有土的ewws。这项研究为开发一种实用的、具有成本效益的分析框架来设计和优化EWs提供了重要的一步，促进了浅层地热能源系统的广泛采用。

{"title":"A novel analytical approach for evaluating thermally active underground retaining walls","authors":"Aakash Gupta , Fleur Loveridge , Ida Shafagh , Simon J. Rees","doi":"10.1016/j.gete.2026.100812","DOIUrl":"10.1016/j.gete.2026.100812","url":null,"abstract":"<div><div>Shallow geothermal energy is a promising renewable technology for sustainable indoor heating and cooling. One method to exploit this energy is through Energy Geostructures, where structural elements embedded in the ground are thermally activated via heat exchange pipes embedded within the structure. These structures function as a specialised form of ground heat exchanger, which can be integrated with ground source heat pump systems. Energy walls (EWs), a specific type of Energy Geostructure, are commonly used in basements, underground parking facilities, and metro stations. Despite their potential, there is currently no simple and reliable analytical method for the thermal analysis of EWs. Instead, their design relies on computationally expensive numerical simulations or oversimplified 'rules of thumb', both of which may lead to inefficiencies in cost and performance. This study presents a novel analytical approach based on the Infinite Plane Source (IPS) model and evaluates its accuracy by comparing it with two-dimensional numerical model data. The results demonstrate that the proposed method provides highly accurate estimates of temperatures at the back of the wall, making it a valuable foundation for future analytical design methodologies. The findings are applicable to EWs having an excavation on one side and ground on the other, as well as fully buried EWs with soil on both sides. This research offers a significant step toward the development of a practical, cost-effective analytical framework for the design and optimisation of EWs, promoting the broader adoption of shallow geothermal energy systems.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100812"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385346","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}

引用次数: 0

Mathematical foundations for play-agnostic thermo-poro-hydro-mechanical modeling of hydraulic fracture initiations from perforated wells: Towards a predictive tool 射孔井水力裂缝起裂的热-孔隙-水力力学模型的数学基础：一种预测工具

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2026-03-01 Epub Date: 2025-12-11 DOI: 10.1016/j.gete.2025.100778

Nassim Bouabdallah, Andreas Michael

The initiation of hydraulically-induced (fluid-driven) fractures for stimulation purposes in hydrocarbon-rich reservoirs can be predictively modeled employing a physics-based approach via a novel pseudo-three-dimensional (pseudo-3D) approximation. The rationale for such an approach lies in the orientation of hydraulic fracture (HF) initiation being determined by mapping stress distributions around the intersection between the wellbore and a perforation tunnel (i.e., the perforation base); the presumed location of HF initiations. The derived closed-form expressions couple thermal, poroelastic, and hydromechanical effects (TPHM) and are controlled by the reservoir’s rock properties and the fluid pressures at the perforation base. Most importantly, this physics-based approach is play-agnostic. The developed TPHM model enables identifying favorable conditions for HFs initiating perpendicularly to the wellbore (“transverse-HF initiations,” as opposed to “longitudinal-HF initiations” axially to the wellbore). This is the desired orientation of HF initiation in virtually every reservoir-stimulation-treatment target zone in today’s prolific low-permeability shale plays; longitudinal-HF initiations can induce several completion and production-related issues triggered by near-wellbore HF tortuosity. The utility of the play-agnostic TPHM model is easily reversible, as it can help estimate the fracture initiation pressure (FIP) at a given orientation of HF initiation. These FIP values provide the basis for formation-breakdown-pressure (FBP) predictions. By solving the derived closed-form expression, our dual-utility, play-agnostic TPHM model provides means for engineers to understand how to manipulate human-controlled parameters from the surface (such as pressurization rates and perforation phasing) to optimize stimulation treatments across various target rock formations, ultimately maximizing the well productivity. Through the promotion of transverse-HF initiation at the lowest possible FBP, near-wellbore fluid tortuosity is suppressed, minimizing early screenouts and enhancing stimulated-well performance that leads to overall more efficient stimulation treatments.

在富含油气的储层中，以增产为目的的水力诱导（流体驱动）裂缝的形成可以采用一种基于物理的方法，通过一种新的伪三维（pseudo-3D）近似方法进行预测建模。这种方法的基本原理是，通过绘制井筒和射孔隧道（即射孔底部）相交处的应力分布来确定水力裂缝（HF）起裂的方向；HF起爆的假定位置。导出的封闭表达式耦合了热、孔弹性和流体力学效应（TPHM），并受储层岩石性质和射孔底部流体压力的控制。最重要的是，这种基于物理的方法是游戏不可知论的。开发的TPHM模型能够识别hf垂直于井筒的有利条件（“横向hf起始”，而不是“纵向hf起始”）。在当今多产的低渗透页岩区，这是几乎所有储层增产处理目标区中HF起爆的理想方向；由于近井HF弯曲，纵向HF起爆会引发一些完井和生产相关的问题。与储层无关的TPHM模型的实用性是很容易逆转的，因为它可以帮助估计在HF起裂的给定方向上的裂缝起裂压力（FIP）。这些FIP值为地层破裂压力（FBP）预测提供了基础。通过求解推导出的封闭表达式，我们的双重实用、不可知储层的TPHM模型为工程师提供了一种方法，让他们了解如何从地面操纵人为控制的参数（如加压速率和射孔相位），以优化不同目标岩层的增产措施，最终实现油井产能最大化。通过在尽可能低的FBP下促进横向hf启动，可以抑制近井流体弯曲度，最大限度地减少早期筛出，提高增产井的性能，从而实现更有效的增产处理。

{"title":"Mathematical foundations for play-agnostic thermo-poro-hydro-mechanical modeling of hydraulic fracture initiations from perforated wells: Towards a predictive tool","authors":"Nassim Bouabdallah, Andreas Michael","doi":"10.1016/j.gete.2025.100778","DOIUrl":"10.1016/j.gete.2025.100778","url":null,"abstract":"<div><div>The initiation of hydraulically-induced (fluid-driven) fractures for stimulation purposes in hydrocarbon-rich reservoirs can be predictively modeled employing a physics-based approach via a novel pseudo-three-dimensional (pseudo-3D) approximation. The rationale for such an approach lies in the orientation of hydraulic fracture (HF) initiation being determined by mapping stress distributions around the intersection between the wellbore and a perforation tunnel (i.e., the perforation base); the presumed location of HF initiations. The derived closed-form expressions couple thermal, poroelastic, and hydromechanical effects (TPHM) and are controlled by the reservoir’s rock properties and the fluid pressures at the perforation base. Most importantly, this physics-based approach is play-agnostic. The developed TPHM model enables identifying favorable conditions for HFs initiating perpendicularly to the wellbore (“transverse-HF initiations,” as opposed to “longitudinal-HF initiations” axially to the wellbore). This is the desired orientation of HF initiation in virtually every reservoir-stimulation-treatment target zone in today’s prolific low-permeability shale plays; longitudinal-HF initiations can induce several completion and production-related issues triggered by near-wellbore HF tortuosity. The utility of the play-agnostic TPHM model is easily reversible, as it can help estimate the fracture initiation pressure (FIP) at a given orientation of HF initiation. These FIP values provide the basis for formation-breakdown-pressure (FBP) predictions. By solving the derived closed-form expression, our dual-utility, play-agnostic TPHM model provides means for engineers to understand how to manipulate human-controlled parameters from the surface (such as pressurization rates and perforation phasing) to optimize stimulation treatments across various target rock formations, ultimately maximizing the well productivity. Through the promotion of transverse-HF initiation at the lowest possible FBP, near-wellbore fluid tortuosity is suppressed, minimizing early screenouts and enhancing stimulated-well performance that leads to overall more efficient stimulation treatments.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100778"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145792131","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}

引用次数: 0

Research on drilling fluid lost circulation and fracture width inversion in complex fractured formations based on fluid-solid coupling 基于流固耦合的复杂裂缝地层钻井液漏失及裂缝宽度反演研究

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2026-03-01 Epub Date: 2026-01-09 DOI: 10.1016/j.gete.2026.100790

Chengyun Ma , Zehan Zheng , Yihua Dou , Wenjun Shan , Wei Wang

Lost circulation in fractured formations is a critical issue, and accurate estimation of fracture width is essential for effective plugging. However, existing analytical models (e.g., Sanfilippo and Civan models) typically involve complex implicit solutions, neglect fracture deformation, and require numerous rock mechanics parameters that are difficult to obtain in real-time. To overcome these limitations, this study developed a 3D multi-scale loss model based on fluid-solid coupling to simulate the loss process dynamically. Based on the simulation results, a rapid fracture width inversion strategy was proposed. A distinct advantage of this approach is its flexibility regarding data availability: inversion models were established for two scenarios—one incorporating fracture density and another excluding it. Specifically, for wells lacking fracture density data (e.g., no imaging logs), the simplified model excluding fracture density allows for accurate prediction using only three readily available parameters: fluid viscosity, pressure differential, and cumulative loss volume. Validated against 48 sets of field data, this simplified model achieved a coefficient of determination (R²) of 0.888 with a relative error of less than 10 %. Compared to traditional methods, the proposed approach significantly reduces parameter requirements and computational complexity, providing a practical and efficient tool for on-site decision-making.

裂缝地层的漏失是一个关键问题，准确估计裂缝宽度对于有效封堵至关重要。然而，现有的分析模型（如Sanfilippo和Civan模型）通常涉及复杂的隐式解，忽略了裂缝变形，并且需要大量难以实时获得的岩石力学参数。为了克服这些局限性，本研究建立了基于流固耦合的三维多尺度损失模型来动态模拟损失过程。基于仿真结果，提出了裂缝宽度快速反演策略。该方法的一个明显优势是其数据可用性的灵活性：针对两种情况建立了反演模型，一种包括裂缝密度，另一种不包括裂缝密度。具体来说，对于缺乏裂缝密度数据（例如，没有成像测井）的井，不包括裂缝密度的简化模型允许仅使用三个现成的参数进行准确预测：流体粘度、压差和累积损失量。经48组野外数据验证，该简化模型的决定系数（R2）为0.888，相对误差小于10 %。与传统方法相比，该方法显著降低了参数要求和计算复杂度，为现场决策提供了实用高效的工具。

{"title":"Research on drilling fluid lost circulation and fracture width inversion in complex fractured formations based on fluid-solid coupling","authors":"Chengyun Ma , Zehan Zheng , Yihua Dou , Wenjun Shan , Wei Wang","doi":"10.1016/j.gete.2026.100790","DOIUrl":"10.1016/j.gete.2026.100790","url":null,"abstract":"<div><div>Lost circulation in fractured formations is a critical issue, and accurate estimation of fracture width is essential for effective plugging. However, existing analytical models (e.g., Sanfilippo and Civan models) typically involve complex implicit solutions, neglect fracture deformation, and require numerous rock mechanics parameters that are difficult to obtain in real-time. To overcome these limitations, this study developed a 3D multi-scale loss model based on fluid-solid coupling to simulate the loss process dynamically. Based on the simulation results, a rapid fracture width inversion strategy was proposed. A distinct advantage of this approach is its flexibility regarding data availability: inversion models were established for two scenarios—one incorporating fracture density and another excluding it. Specifically, for wells lacking fracture density data (e.g., no imaging logs), the simplified model excluding fracture density allows for accurate prediction using only three readily available parameters: fluid viscosity, pressure differential, and cumulative loss volume. Validated against 48 sets of field data, this simplified model achieved a coefficient of determination (R<sup>2</sup>) of 0.888 with a relative error of less than 10 %. Compared to traditional methods, the proposed approach significantly reduces parameter requirements and computational complexity, providing a practical and efficient tool for on-site decision-making.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100790"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978137","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}

引用次数: 0

Cyclic thermally-induced axial load for energy piles embedded in a saturated soft clay 饱和软土中埋置能源桩的循环热诱导轴向荷载

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2026-03-01 Epub Date: 2026-02-13 DOI: 10.1016/j.gete.2026.100804

Chiara Iodice, Raffaele Di Laora, Alessandro Mandolini

Energy piles are subjected to cyclic thermal loads during the entire lifespan which act in conjunction with the mechanical solicitations by the overlying structure, complying with the double role of heat exchangers and load transferring elements. When installed in soft soil they show accumulation of cyclic displacements which are larger in magnitude in case of clay subjected to thermal collapse. Possible effects of the latter phenomenon on the thermally-induced axial load are investigated in this study through fully coupled thermo-hydro-mechanical numerical analyses of a single energy pile embedded in a normally consolidated saturated clay. The simulations are carried out also employing some advanced constitutive models for the soil to capture peculiar behavioral aspects. The results are presented in terms of thermally-induced axial force along the energy pile and its evolution cycle after cycle. The comparison between the models allowed to isolate the role of the thermal collapse on the pile performance and investigate the suitability of simpler models to describe the pile-soil interaction. A strong dependence of axial force on the cyclic thermal load was found, highlighting the importance of considering such aspect in the energy pile design.

能源桩在整个使用寿命期间都要承受循环热负荷，这些热负荷与上覆结构的机械载荷共同作用，符合热交换器和负荷传递元件的双重作用。当安装在软土中时，它们表现出循环位移的积累，在粘土遭受热崩溃的情况下，循环位移的量级更大。本文通过对正常固结饱和粘土中单能量桩的热-水-力全耦合数值分析，探讨了后一种现象对热诱导轴向载荷的可能影响。模拟还采用了一些先进的土的本构模型来捕捉特殊的行为方面。分析了沿能量桩的热诱导轴力及其循环演化规律。通过模型间的比较，可以分离出热崩溃对桩性能的影响，并研究更简单的模型来描述桩-土相互作用的适用性。发现轴向力对循环热负荷有很强的依赖性，突出了在能源桩设计中考虑这方面的重要性。

{"title":"Cyclic thermally-induced axial load for energy piles embedded in a saturated soft clay","authors":"Chiara Iodice, Raffaele Di Laora, Alessandro Mandolini","doi":"10.1016/j.gete.2026.100804","DOIUrl":"10.1016/j.gete.2026.100804","url":null,"abstract":"<div><div>Energy piles are subjected to cyclic thermal loads during the entire lifespan which act in conjunction with the mechanical solicitations by the overlying structure, complying with the double role of heat exchangers and load transferring elements. When installed in soft soil they show accumulation of cyclic displacements which are larger in magnitude in case of clay subjected to thermal collapse. Possible effects of the latter phenomenon on the thermally-induced axial load are investigated in this study through fully coupled thermo-hydro-mechanical numerical analyses of a single energy pile embedded in a normally consolidated saturated clay. The simulations are carried out also employing some advanced constitutive models for the soil to capture peculiar behavioral aspects. The results are presented in terms of thermally-induced axial force along the energy pile and its evolution cycle after cycle. The comparison between the models allowed to isolate the role of the thermal collapse on the pile performance and investigate the suitability of simpler models to describe the pile-soil interaction. A strong dependence of axial force on the cyclic thermal load was found, highlighting the importance of considering such aspect in the energy pile design.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100804"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385347","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}

引用次数: 0

A feasibility study of a modal analysis-based acoustic method for noninvasively estimating elastic properties of rocks 基于模态分析的声学方法无创估计岩石弹性特性的可行性研究

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2026-03-01 Epub Date: 2026-02-06 DOI: 10.1016/j.gete.2026.100799

Sanjay Mahat , Sugan Raj Thiyagarajan , Ezekiel Anguiano , Hossein Emadibaladehi , Qingwang Yuan , Jingfei Liu

Accurate characterization of rock's elastic properties is fundamentally important for geomechanical analysis. Yet, conventional static and dynamic characterization techniques, such as Young’s modulus (E) and Poisson’s ratio (ν) measurements, often demand strict sample preparation, specific positioning, and costly equipment. This study introduces and assesses the feasibility of a modal analysis-based acoustic method in the field of geomechanics, which significantly reduces the strict requirements of traditional measurement methods and allows for the more flexible and nondestructive determination of rock elastic constants. The approach combines experimental acoustic measurements and numerical modal analysis. First, the sounds of a shale sample vibrating under free-boundary conditions are generated via gentle mechanical impacts and recorded; the recorded acoustic data are analyzed to determine its natural frequencies. Then, a finite element model of the rock sample under test iteratively simulates the modal response across various elastic properties to identify the best (E, ν) combination. By minimizing the difference between simulated and measured frequencies, the optimal estimation of (E, ν) will be identified as the rock sample’s mechanical property measurements. Validation of the proposed method was performed by comparing the results with those obtained from established dynamic and static techniques using samples from the same source. The elastic moduli obtained via the acoustic method (E = 53.8 GPa, ν = 0.274), closely matched those from the ultrasound pulse-echo method (E = 57.1 GPa, ν = 0.261), with differences of −5.8 % and 5.0 %, respectively. Results also aligned with established theory, consistent with typical finding that rocks’ dynamic moduli are higher than their static moduli. These findings demonstrate that the modal analysis-based acoustic technique can be a robust and reliable method for nondestructive evaluation of effective elastic properties in shale rock samples. It offers a practical, accessible alternative for geomechanical characterization by relaxing geometric constraints, simplifying experiments, and reducing costs.

岩石弹性特性的准确表征对地质力学分析至关重要。然而，传统的静态和动态表征技术，如杨氏模量(E)和泊松比（ν）测量，通常需要严格的样品制备、特定的定位和昂贵的设备。本研究介绍并评估了地质力学领域中基于模态分析的声学方法的可行性，该方法大大降低了传统测量方法的严格要求，并允许更灵活和无损地确定岩石弹性常数。该方法结合了实验声学测量和数值模态分析。首先，在自由边界条件下，通过温和的机械冲击产生页岩样品振动的声音并记录下来；对记录的声学数据进行分析以确定其固有频率。然后，对被试岩石试样建立有限元模型，迭代模拟不同弹性特性下的模态响应，以确定最佳（E, ν）组合。通过最小化模拟频率和测量频率之间的差异，（E, ν）的最佳估计将被确定为岩石样品的力学特性测量值。通过将来自同一来源的样品与已建立的动态和静态技术获得的结果进行比较，验证了所提出的方法。声波法得到的弹性模量（E = 53.8 GPa, ν = 0.274）与超声脉冲回波法得到的弹性模量（E = 57.1 GPa, ν = 0.261）非常接近，两者的差值分别为−5.8 %和5.0 %。结果也与已建立的理论相一致，与岩石的动态模量高于静态模量的典型发现一致。这些结果表明，基于模态分析的声学技术是一种可靠的无损评估页岩样品有效弹性特性的方法。它通过放松几何约束、简化实验和降低成本，为地质力学表征提供了一种实用、可访问的替代方案。

{"title":"A feasibility study of a modal analysis-based acoustic method for noninvasively estimating elastic properties of rocks","authors":"Sanjay Mahat , Sugan Raj Thiyagarajan , Ezekiel Anguiano , Hossein Emadibaladehi , Qingwang Yuan , Jingfei Liu","doi":"10.1016/j.gete.2026.100799","DOIUrl":"10.1016/j.gete.2026.100799","url":null,"abstract":"<div><div>Accurate characterization of rock's elastic properties is fundamentally important for geomechanical analysis. Yet, conventional static and dynamic characterization techniques, such as Young’s modulus (<em>E</em>) and Poisson’s ratio (<em>ν</em>) measurements, often demand strict sample preparation, specific positioning, and costly equipment. This study introduces and assesses the feasibility of a modal analysis-based acoustic method in the field of geomechanics, which significantly reduces the strict requirements of traditional measurement methods and allows for the more flexible and nondestructive determination of rock elastic constants. The approach combines experimental acoustic measurements and numerical modal analysis. First, the sounds of a shale sample vibrating under free-boundary conditions are generated via gentle mechanical impacts and recorded; the recorded acoustic data are analyzed to determine its natural frequencies. Then, a finite element model of the rock sample under test iteratively simulates the modal response across various elastic properties to identify the best (<em>E, ν</em>) combination. By minimizing the difference between simulated and measured frequencies, the optimal estimation of (<em>E, ν</em>) will be identified as the rock sample’s mechanical property measurements. Validation of the proposed method was performed by comparing the results with those obtained from established dynamic and static techniques using samples from the same source. The elastic moduli obtained via the acoustic method (<em>E</em> = 53.8 GPa, <em>ν</em> = 0.274), closely matched those from the ultrasound pulse-echo method (<em>E</em> = 57.1 GPa, <em>ν</em> = 0.261), with differences of −5.8 % and 5.0 %, respectively. Results also aligned with established theory, consistent with typical finding that rocks’ dynamic moduli are higher than their static moduli. These findings demonstrate that the modal analysis-based acoustic technique can be a robust and reliable method for nondestructive evaluation of effective elastic properties in shale rock samples. It offers a practical, accessible alternative for geomechanical characterization by relaxing geometric constraints, simplifying experiments, and reducing costs.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100799"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146173574","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}

引用次数: 0

Enhanced soil-pile friction using colloidal silica grouting in granular soils 颗粒土中硅胶灌浆增强桩土摩擦

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2026-03-01 Epub Date: 2025-12-13 DOI: 10.1016/j.gete.2025.100780

Alvaro Boiero , Enrique Romero , Marcos Arroyo , Giovanni Spagnoli

Grouting the soil–pile interface can significantly enhance shaft friction in driven and vibrated piles. This observation is well documented for conventional cementitious grouts, but not for alternative low-carbon grouts. In this study the potential of a novel low-viscosity binder—colloidal silica (CS)—to improve steel–granular soil interfaces is explored. Direct shear tests under constant normal stiffness were performed to simulate sand–pile interface behavior on quartz sand specimens permeated with CS. A range of initial relative densities, initial effective normal stresses and constant normal spring stiffness values was selected to mimic conditions likely to be encountered by long piles on offshore sedimentary environments. The study examines the influence of CS dosage and of steel interface roughness. Pre- and post-grout interface shear tests were conducted to evaluate the influence of injection. The results demonstrate that colloidal silica significantly increases interface friction. Practical implications for pile design are discussed.

对桩土界面进行注浆，可显著提高桩身摩阻力。这一观察结果在常规胶凝注浆中得到了很好的证明，但在替代低碳注浆中却没有得到证实。本研究探讨了一种新型低粘度粘结剂——胶体二氧化硅（CS）改善钢-颗粒-土壤界面的潜力。采用恒法向刚度直剪试验模拟了CS渗透石英砂试件的砂-桩界面特性。选择一系列初始相对密度、初始有效正应力和恒定的正向弹簧刚度值来模拟近海沉积环境中长桩可能遇到的情况。研究了CS用量和钢界面粗糙度的影响。通过注浆前和注浆后界面剪切试验，评价注浆对注浆效果的影响。结果表明，胶体二氧化硅显著增加了界面摩擦力。讨论了桩设计的实际意义。

引用次数: 0

Coupled stress–apparent resistivity model for rock deformation and failure based on experimental analysis 基于实验分析的岩石变形破坏耦合应力-视电阻率模型

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2026-03-01 Epub Date: 2026-01-13 DOI: 10.1016/j.gete.2026.100792

Zhongzhong Xu , Jiulong Cheng , Hongpeng Zhao

The key to preventing mine water disasters and gas hazards lies in monitoring the development of mining–induced fractures in the roof strata of coal seams. Although the borehole resistivity method (BRM) is an advanced technology, its effectiveness is limited by the incomplete understanding of how the apparent resistivity of rock varies during the development of mining-induced fractures and the difficulty in quantitatively analyzing the extent of fracture development. This study used experimental analysis to identify the patterns governing the apparent resistivity changes of rock throughout the development of mining-induced fractures under different confining pressure levels and to formulate a quantitative model for assessing rock fracture development. The study examined stress and the apparent resistivity of five rock types under three confining pressure levels. The results reveal that the relationship between stress and apparent resistivity in loaded rocks is characterized by distinct stage–dependent variations. Specifically, during the microcrack closure stage, there is a negative linear correlation between the apparent resistivity of the rock and stress. In the linear elastic stage, the apparent resistivity of identical rocks remains stable and consistent across varying confining pressure levels. Conversely, in the stable crack propagation and failure stages, a positive linear correlation is observed between the apparent resistivity of the rock and stress. Utilizing experimental data, a coupled stress–apparent resistivity model for rock deformation and failure (CSAR model) was developed. This study not only improves the precision of BRM in monitoring mining-induced fracture development in coal seam roof strata but also tackles the challenges of quantitatively analyzing the extent of fracture development.

预防矿井水害和瓦斯危害的关键是监测煤层顶板采动裂隙的发育情况。虽然钻孔电阻率法（BRM）是一项先进的技术，但由于对采动裂缝发育过程中岩石视电阻率变化的认识不完全，以及对裂缝发育程度的定量分析困难，限制了其有效性。通过实验分析，确定了不同围压水平下采动裂隙发育过程中岩石视电阻率变化规律，建立了评价岩石裂隙发育的定量模型。研究了3种围压水平下5种岩石的应力和视电阻率。结果表明，加载岩石中应力与视电阻率的关系具有明显的阶段性变化特征。具体而言，在微裂纹闭合阶段，岩石视电阻率与应力呈负线性相关。在线弹性阶段，同一岩石的视电阻率在不同围压水平下保持稳定一致。相反，在稳定裂纹扩展和破坏阶段，岩石视电阻率与应力呈线性正相关。利用实验数据，建立了岩石变形破坏的应力-视电阻率耦合模型（CSAR模型）。该研究不仅提高了BRM监测煤层顶板采动裂隙发育的精度，而且解决了裂隙发育程度定量分析的难题。

{"title":"Coupled stress–apparent resistivity model for rock deformation and failure based on experimental analysis","authors":"Zhongzhong Xu , Jiulong Cheng , Hongpeng Zhao","doi":"10.1016/j.gete.2026.100792","DOIUrl":"10.1016/j.gete.2026.100792","url":null,"abstract":"<div><div>The key to preventing mine water disasters and gas hazards lies in monitoring the development of mining–induced fractures in the roof strata of coal seams. Although the borehole resistivity method (BRM) is an advanced technology, its effectiveness is limited by the incomplete understanding of how the apparent resistivity of rock varies during the development of mining-induced fractures and the difficulty in quantitatively analyzing the extent of fracture development. This study used experimental analysis to identify the patterns governing the apparent resistivity changes of rock throughout the development of mining-induced fractures under different confining pressure levels and to formulate a quantitative model for assessing rock fracture development. The study examined stress and the apparent resistivity of five rock types under three confining pressure levels. The results reveal that the relationship between stress and apparent resistivity in loaded rocks is characterized by distinct stage–dependent variations. Specifically, during the microcrack closure stage, there is a negative linear correlation between the apparent resistivity of the rock and stress. In the linear elastic stage, the apparent resistivity of identical rocks remains stable and consistent across varying confining pressure levels. Conversely, in the stable crack propagation and failure stages, a positive linear correlation is observed between the apparent resistivity of the rock and stress. Utilizing experimental data, a coupled stress–apparent resistivity model for rock deformation and failure (CSAR model) was developed. This study not only improves the precision of BRM in monitoring mining-induced fracture development in coal seam roof strata but also tackles the challenges of quantitatively analyzing the extent of fracture development.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100792"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978135","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}

引用次数: 0

Finite element analysis of laterally loaded open-ended steel piles driven in chalk 白垩灌注桩横向受力的有限元分析

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2026-03-01 Epub Date: 2026-02-06 DOI: 10.1016/j.gete.2026.100800

Stavroula Kontoe , Giuseppe Pedone , Enrico Bellumat , Richard Jardine

Open-ended steel piles are commonly driven to support offshore wind energy structures. Their design poses significant challenges in chalk, a very weak brittle limestone found in several regions worldwide. Impact driving causes chalk de-structuration and fracturing around the piles, greatly affecting their lateral load-bearing performance. This was observed in recent field tests undertaken in the UK on piles with different lengths, diameters and thicknesses, exhibiting both geotechnical and structural failures. Most of these lateral loading tests, including those conducted on larger and longer monopiles, were completed recently and were never analysed numerically. This paper presents results of 3D Finite Element analyses conducted on open-ended steel piles with different diameters (up to 1.22 m), embedded lengths (up to 10.16 m) and wall thicknesses (up to 44.5 mm), allowing to explore the marked scale effects observed on site. The newly available field tests also showed that steel yielding can occur before geotechnical failure is reached in chalk when testing piles with practical dimensions. However, steel yielding is usually neglected when modelling soil-pile interaction in geotechnical applications. The paper also aims at covering this gap by introducing a simplified modelling approach to account for elasto-plastic pile behaviour. The analyses delivered generally good matches with field behaviour and allowed to explore the main geotechnical uncertainties affecting accurate pile-chalk interaction predictions, mainly including the extent of the chalk fracturing induced by pile driving and its impact on chalk mechanical properties. The studies provide new and vital guidance for those involved in designing large driven piles for chalk sites.

开放式钢桩通常用于支撑海上风能结构。他们的设计在白垩中提出了重大挑战，白垩是一种非常脆弱的易碎石灰岩，在全球几个地区都有发现。冲击驱动引起桩周白垩破坏和破裂，极大地影响了桩的横向承载性能。最近在英国对不同长度、直径和厚度的桩进行的现场测试中观察到这一点，显示出岩土和结构的破坏。大多数这些横向荷载试验，包括在较大和较长的单桩上进行的试验，都是最近完成的，从未进行过数值分析。本文介绍了对不同直径（不超过1.22 m）、埋深（不超过10.16 m）和壁厚（不超过44.5 mm）的开放式钢桩进行三维有限元分析的结果，从而探讨了在现场观察到的明显的尺度效应。新获得的现场试验也表明，在实际尺寸的试桩中，在白垩土中达到岩土破坏之前，钢就会发生屈服。然而，在岩土工程应用中，当模拟土桩相互作用时，通常忽略了钢的屈服。本文还旨在通过引入一种简化的建模方法来解释弹塑性桩的行为来弥补这一差距。分析结果总体上与现场行为吻合良好，并允许探索影响准确的桩-白垩相互作用预测的主要岩土不确定性，主要包括打桩引起的白垩断裂程度及其对白垩力学特性的影响。研究结果为白垩场地大型沉桩设计提供了新的重要指导。

{"title":"Finite element analysis of laterally loaded open-ended steel piles driven in chalk","authors":"Stavroula Kontoe , Giuseppe Pedone , Enrico Bellumat , Richard Jardine","doi":"10.1016/j.gete.2026.100800","DOIUrl":"10.1016/j.gete.2026.100800","url":null,"abstract":"<div><div>Open-ended steel piles are commonly driven to support offshore wind energy structures. Their design poses significant challenges in chalk, a very weak brittle limestone found in several regions worldwide. Impact driving causes chalk de-structuration and fracturing around the piles, greatly affecting their lateral load-bearing performance. This was observed in recent field tests undertaken in the UK on piles with different lengths, diameters and thicknesses, exhibiting both geotechnical and structural failures. Most of these lateral loading tests, including those conducted on larger and longer monopiles, were completed recently and were never analysed numerically. This paper presents results of 3D Finite Element analyses conducted on open-ended steel piles with different diameters (up to 1.22 m), embedded lengths (up to 10.16 m) and wall thicknesses (up to 44.5 mm), allowing to explore the marked scale effects observed on site. The newly available field tests also showed that steel yielding can occur before geotechnical failure is reached in chalk when testing piles with practical dimensions. However, steel yielding is usually neglected when modelling soil-pile interaction in geotechnical applications. The paper also aims at covering this gap by introducing a simplified modelling approach to account for elasto-plastic pile behaviour. The analyses delivered generally good matches with field behaviour and allowed to explore the main geotechnical uncertainties affecting accurate pile-chalk interaction predictions, mainly including the extent of the chalk fracturing induced by pile driving and its impact on chalk mechanical properties. The studies provide new and vital guidance for those involved in designing large driven piles for chalk sites.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100800"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146173496","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}

引用次数: 0

Analytical solutions for transient response of a semi-permeable wellbore subjected to non-hydrostatic in situ stresses and convective boundary conditions within a transversely isotropic thermoporoelastic medium 在横向各向同性热孔弹性介质中，受非静水原位应力和对流边界条件影响的半渗透井眼瞬态响应解析解

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2026-03-01 Epub Date: 2026-02-10 DOI: 10.1016/j.gete.2026.100801

Zhaokun Li , Chongyuan Zhang , Zhiqiang Fan , Yang Qiu , Xinghao Li , Lixin Zhao

Accurately characterizing the transient thermoporoelastic behavior surrounding boreholes in shale reservoirs is essential for maintaining well integrity and optimizing drilling efficiency. However, conventional analytical frameworks typically oversimplify borehole boundary conditions as strictly permeable or impermeable, neglecting the selective semi-permeable nature observed in realistic geological settings. Here, we develop an analytical solution explicitly accommodating semi-permeable boundaries that regulate the passage of fluid molecules while preventing solute transport, integrating this sophisticated boundary representation with intrinsic material anisotropy. Leveraging a fully coupled thermoporoelastic formulation complemented by a load decomposition strategy, our analysis reveals that material anisotropy exerts a substantial yet temporally diminishing influence on hoop stresses. In particular, pronounced stress perturbations are detected during early response periods due to anisotropic mechanical properties, diminishing over time as equilibrated conditions emerge within the formation. Concurrently, initial pore pressure fields exhibit marked spatial variability, driven predominantly by anisotropic characteristics and regulated by the dimensionless permeability parameter π_f. This parameter critically modulates the transient redistribution of stress and fluid pressure: low π_f scenarios, representative of more permeable interfaces, intensify near-wellbore pore-pressure gradients and hoop stress peaks, whereas increased π_f —indicative of restricted permeability—tends to stabilize these fields, yielding comparatively homogeneous distributions. Ultimately, our findings emphasize that incorporating realistic semi-permeable boundary conditions along with material anisotropy is indispensable for accurately predicting temporal evolutions of pore pressures and hoop stresses, thereby enhancing the reliability of wellbore stability assessments in complex anisotropic shale formations.

准确表征页岩储层井眼周围的瞬态热孔弹性行为对于保持井的完整性和优化钻井效率至关重要。然而，传统的分析框架通常将井眼边界条件简化为严格渗透性或不渗透性，而忽略了在实际地质环境中观察到的选择性半渗透性。在这里，我们开发了一个解析解，明确地容纳半渗透边界，该边界调节流体分子的通过，同时防止溶质运输，将这种复杂的边界表示与固有的材料各向异性相结合。利用完全耦合的热孔弹性公式和负载分解策略，我们的分析表明，材料的各向异性对环向应力产生了实质性的但暂时递减的影响。特别是，由于各向异性力学特性，在早期响应期间可以检测到明显的应力扰动，随着时间的推移，随着地层内平衡条件的出现，应力扰动会逐渐减小。同时，初始孔隙压力场表现出明显的空间变异性，主要受各向异性特征驱动，并受无量纲渗透率参数πf的调节。该参数对应力和流体压力的瞬态分布具有重要的调节作用：πf值较低时，表明界面渗透性较好，会加剧近井孔隙压力梯度和环向应力峰值，而πf值较高时，表明渗透率受限，趋于稳定，分布相对均匀。最后，我们的研究结果强调，结合真实的半渗透边界条件以及材料各向异性对于准确预测孔隙压力和环向应力的时间演变是必不可少的，从而提高了复杂各向异性页岩地层井筒稳定性评估的可靠性。

{"title":"Analytical solutions for transient response of a semi-permeable wellbore subjected to non-hydrostatic in situ stresses and convective boundary conditions within a transversely isotropic thermoporoelastic medium","authors":"Zhaokun Li , Chongyuan Zhang , Zhiqiang Fan , Yang Qiu , Xinghao Li , Lixin Zhao","doi":"10.1016/j.gete.2026.100801","DOIUrl":"10.1016/j.gete.2026.100801","url":null,"abstract":"<div><div>Accurately characterizing the transient thermoporoelastic behavior surrounding boreholes in shale reservoirs is essential for maintaining well integrity and optimizing drilling efficiency. However, conventional analytical frameworks typically oversimplify borehole boundary conditions as strictly permeable or impermeable, neglecting the selective semi-permeable nature observed in realistic geological settings. Here, we develop an analytical solution explicitly accommodating semi-permeable boundaries that regulate the passage of fluid molecules while preventing solute transport, integrating this sophisticated boundary representation with intrinsic material anisotropy. Leveraging a fully coupled thermoporoelastic formulation complemented by a load decomposition strategy, our analysis reveals that material anisotropy exerts a substantial yet temporally diminishing influence on hoop stresses. In particular, pronounced stress perturbations are detected during early response periods due to anisotropic mechanical properties, diminishing over time as equilibrated conditions emerge within the formation. Concurrently, initial pore pressure fields exhibit marked spatial variability, driven predominantly by anisotropic characteristics and regulated by the dimensionless permeability parameter <em>π</em><sub><em>f</em></sub>. This parameter critically modulates the transient redistribution of stress and fluid pressure: low <em>π</em><sub><em>f</em></sub> scenarios, representative of more permeable interfaces, intensify near-wellbore pore-pressure gradients and hoop stress peaks, whereas increased <em>π</em><sub><em>f</em></sub> —indicative of restricted permeability—tends to stabilize these fields, yielding comparatively homogeneous distributions. Ultimately, our findings emphasize that incorporating realistic semi-permeable boundary conditions along with material anisotropy is indispensable for accurately predicting temporal evolutions of pore pressures and hoop stresses, thereby enhancing the reliability of wellbore stability assessments in complex anisotropic shale formations.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100801"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146173575","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}

引用次数: 0

Feedback on the discussion of “assessment of an amended soil as a climate adaptive barrier: Element testing and physical modelling” 对“作为气候适应屏障的改良土壤的评估：元素测试和物理模型”讨论的反馈

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2026-03-01 Epub Date: 2026-02-07 DOI: 10.1016/j.gete.2026.100803

Aditi Rana , Ashutosh Kumar , Arash Azizi , Ashraf Osman , David G. Toll

引用次数: 0

首页上一页