检索结果-内蒙古大学图书馆

Mechanical behavior of EICP-treated calcareous sands under high confining pressures

Journal of Rock Mechanics and geotechnical {1. 2025年第3期17卷 1816-1827页

作者： Qian Zhang Weimin Ye Wei Su Qiong Wang Yonggui Chen Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai200092China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai200092China

Calcareous sands are widely distributed on the coral reefs,continental shelf,and seashores between 30north and south latitude and are commonly utilized as filling materials for the construction of artificial islands and infrastructure *** this study,calcareous sands were cemented by enzymatically induced carbonate precipitation(EICP)*** triaxial tests were conducted on the EICPtreated calcareous *** showed that the specimens with different cementation levels exhibited different responses in mechanical *** differences in the sand fabric after consolidation under a relatively high confining pressure resulted in the untreated specimen exhibiting a higher peak strength compared to the lightly cemented *** confining pressures exhibited a strongly inhibiting effect on dilatancy,which could be counteracted by increasing the cementation *** EICP-treated specimen could have one or two yield points(smaller-strain and larger-strain yields).For lightly cemented specimens,the smaller-strain yield stress decreased under high confining pressures due to the partial carbonate bonding degradation during *** stress line of untreated particle breakage(UPB)was a critical boundary to distinguish failure mode in the p′-q *** the EICP-treated specimens,the yield stress located above or below the UPB stress line indicates the simultaneous or sequential breakage of the carbonate bonds and sand particles,***,the EICPtreated specimen exhibited brittle or ductile *** mode transformation could be triggered by increasing cementation level or confining pressure.

关键词： EICP technique Calcareous sand Bonding degradation Yield strength Failure mechanism

来源：评论

学校读者我要写书评

暂无评论

Thermal effects on the strain rate-dependent behavior of highly compacted GMZ01.bentonite

引用

Journal of Rock Mechanics and geotechnical {1. 2025年第1期17卷 453-464页

作者： Pengju Qin Weimin Ye Qiong Wang Yonggui Chen College of Civil Engineering Taiyuan University of TechnologyTaiyuan030024China Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai200092China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai200092China

Investigation of thermal effects on the strain rate-dependent properties of compacted bentonite is crucial for the long-term safety assessment of deep geological repository for disposal of high-level radioactive *** the present work,cylindrical GMZ01.bentonite specimens were compacted with suction-controlled by the vapor equilibrium ***,a series of temperature-and suction-controlled stepwise constant rate of strain(CRS)tests was performed and the rate-dependent compressibility behavior of the highly compacted GMZ01.bentonite was *** plastic compressibility parameterλ,the elastic compressibility parameterκ,the yield stress p0,as well as the viscous parameterαwere *** indicate thatλ,κandαdecrease and p0 increases as suction *** heating,parametersλ,αand p0 *** is also found that p0 increases linearly with increasing CRS in a double-logarithm *** on the experimental results,a viscosity parameterα(s,T)was fitted to capture the effects of suction s and temperature T on the relationship between yield stress and strain ***,an elastic-thermo-viscoplastic model for unsaturated soils was developed to describe the thermal effects on the rate-dependent behavior of highly compacted GMZ01.*** showed that the calculated results agreed well to the measured ones.

关键词： Highly compacted bentonite Rate-dependent behavior Constant rate of strain Temperature Elastic-thermo-viscoplastic model

来源：评论

学校读者我要写书评

暂无评论

Thermal Effect on the Breakdown Pressure of Granite in Supercritical CO2 Fracturing: Experimental Study and Model Validation

引用

SPE Journal 2025年第4期30卷 1740-1755页

作者： Liu, Shuyuan Zhu, Wancheng Liu, Heyang Wei, Chenhui Zhang, Xiufeng Liu, Zhengdong Center for Rock Instability and Seismicity Research Department of Mining Engineering School of Resource and Civil Engineering Northeastern University Shenyang China Tongji University Key Laboratory of Geotechnical and Underground Engineering Ministry of Education Shanghai China

Breakdown pressure (Pb) is a key parameter in supercritical carbon dioxide (SC-CO2) fracturing technology. A limited understanding of the thermal effects resulting from the difference between SC-CO2 and reservoir temperatures impedes accurate Pb prediction. In our work, fracturing experiments were conducted on granite to analyze the impacts of temperature and injection rate in terms of the thermal effects on Pb. Additionally, we establish an effective Pb prediction model that considers thermal effects, achieving a low error rate relative to the experimental data. As the temperature increases from 308 to 328 and 348 K, the experimental Pb decreases by 8.34% and 20.35%, respectively. The rising temperature reduces the viscosity and pressurization rate of SC-CO2, thereby increasing the stress caused by the infiltration effect, which is inversely related to Pb. As the temperature difference increases from 0 to 20 and 60 K, the experimental Pb decreases by 3.27% and 1..1.%, respectively. The thermal stress induced by these temperature differences negatively impacts Pb, and increases in temperature difference enhance thermal stress and weaken the pore pressure at the characteristic length dw. As the injection rate increases from 30 to 50 and 70 mL/min, the experimental Pb increases by 4.84% and 1..38%, respectively. The weakened infiltration effect and reduced thermal stress at dw increase the Pb under faster injection rates. Increased temperature differences and lower injection rates significantly reduce the breakdown pressure of low-permeability rocks due to combined thermal stress and fluid infiltration but have relatively minor effects on high-permeability rocks. Copyright © 2025 Society of Petroleum Engineers.

关键词： Granite

来源：评论

学校读者我要写书评

暂无评论

A modified state parameter for identifying flow liquefaction in aeolian sand

引用

Geotechnique Letters 2025年第2期15卷 1-9页

作者： Xu, Wendong Li, Xuefeng Zeng, Sheng Tang, Zhenghui Lü, Xilin Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Department of Geotechnical Engineering Tongji University Shanghai China School of Civil and Hydraulic Engineering Ningxia University Yinchuan China Department of Civil Engineering University of British Columbia VancouverBC Canada Guangxi Communications Design Group Co. Ltd Guangxi Nanning530029 China

Static liquefaction is when sandy soils lose shear strength and deform rapidly under undrained shearing. This phenomenon has three undrained responses: flow, limited flow, and nonflow (not liquefied). Among them, flow is the most dangerous, marked by complete strength loss and significant deformation. Thus, recognizing flow liquefaction is crucial in interpreting liquefaction behaviors. Aeolian sand which has low fine content, non-cohesion, and poor size distribution, was found to be highly liquefiable, and so was used to explore the liquefaction characteristics via undrained triaxial tests with different initial stresses and void ratios. The experimental results showed an obvious effect of stress on the flow behavior of liquefaction in aeolian sand. A modified state parameter corrected by critical mean effective stress and void ratio was introduced to consider the stress effect. It was proved to identify the flow behavior on aeolian sand successfully, based on the value of the modified state parameter. A state-dependent hardening plasticity model, incorporating the modified state parameter, was introduced. This model effectively simulates undrained triaxial tests on aeolian sand, accurately capturing all behavior types: flow, limited flow, and nonflow responses. © 2025 Emerald Publishing Limited: All rights reserved.

关键词： Soil liquefaction

来源：评论

学校读者我要写书评

暂无评论

Diagnosing building moisture conditions using CNN analysis of infrared and microwave signatures 2

Diagnosing building moisture conditions using CNN analysis o...

引用

2nd International Academic Conference on Optics and Photonics, IACOP 2024

作者： Wang, Fuzhi Fang, Maoliu Huang, Jizhong Lu, Yuan Department of Geotechnical Engineering College of Civil Engineering Tongji University Shanghai200092 China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji University Shanghai200092 China Department of Civil Engineering Shanghai University Shanghai200444 China

ISBN: (数字)9781510688827

ISBN: (纸本)9781510688810

Water is a significant cause of cultural heritage deterioration, making moisture detection crucial for heritage conservation. This study utilizes infrared thermography (IRT) in combination with microwave technology to quantitatively and qualitatively assess moisture distribution and dampness-related deterioration in China's Yungang Grottoes. The method accurately diagnoses moisture content and distribution by using a Convolutional Neural Network (CNN) for multi-feature image fusion. Non-destructive techniques and statistical analyses, such as signal-to-noise ratio (SNR) and spatial stability, improve the detection of moisture damage. Statistical analysis confirmed the accuracy of IRT and microwave technology for qualitative and quantitative moisture assessment, providing valuable support for conservation and management strategies. © 2025 SPIE.

关键词： Nondestructive examination

来源：评论

学校读者我要写书评

暂无评论

New performance indicator-enabled fragility evaluation of tunnels subjected to combined fault rupture and subsequent seismic excitation

引用

Tunnelling and underground Space Technology 2025年 163卷

作者： Zhang, Chenlong Zhang, Dongming Huang, Zhongkai Shen, Yiyao Zhang, Dongmei Huang, Hongwei Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Department of Geotechnical Engineering Tongji University Shanghai200092 China

Cross-fault tunnels subjected to combined fault rupture and subsequent seismic excitation exhibit complex deformation patterns and damage mechanisms, posing great risk to their long-term operation. To address this critical challenge, a novel performance indicator is proposed and applied to the fragility assessment of tunnel structures, aiming to evaluate the compounded effects of both fault rupture propagation and subsequent seismic excitation. Firstly, the numerical model is developed to simulate the tunnels’ structural response under varying hazard scenarios. Subsequently, performance indices are introduced to assess both global deformation and localized damage in the tunnel structure. Through integrated analysis of the tunnel's nonlinear response characteristics and lining damage progression, performance-based threshold criteria are established to classify distinct damage states according to the proposed indicator. Compared with conventional performance indices, the proposed indices undergo a comprehensive multi-criteria evaluation to verify their correlation strength and assessment efficiency. Following the establishment of damage state thresholds, a demand function is developed to quantify the combined probability of fault rupture and seismic excitation for cross-fault tunnel. A fragility surface is then analytically characterized by incorporating a dual-hazard intensity measure that accounts for seismic excitation and fault rupture effects. Consequently, a comprehensive probabilistic model is established for quantifying the likelihood of different damage states in tunnel structures. The developed new performance indicator and fragility assessment methodology enables quantitative assessment of tunnel damage probabilities, thus playing a vital role in the construction of resilient cross-fault tunnel. © 2025 Elsevier Ltd

关键词： Impulse response

来源：评论

学校读者我要写书评

暂无评论

Parametric deep learning model for predicting bearing capacity of strip foundation via neural operator

引用

AI in Civil engineering 2025年第1期4卷 1-14页

作者： Niu, Tongtong Huang, Maosong Yu, Jian Department of Geotechnical Engineering Tongji University Shanghai China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji University Shanghai China

Strip foundations, as a widely applied form of shallow foundation, involve foundation displacements and soil deformations under loading, which are critical issues in geotechnical {1.. Traditional limit analysis methods can only provide solutions for ultimate bearing capacity, while numerical methods require remeshing and remodeling for different scenarios. To address these challenges, this study proposes a deep learning approach based on the DeepONet neural operator for rapid and accurate predictions of load–displacement curves and vertical displacement fields of strip foundations under various conditions. A dataset with randomly distributed parameters was generated using finite element method, with the training set employed to train the neural network. Validation on the test set shows that the proposed method not only accurately predicts ultimate bearing capacity but also captures the nonlinear characteristics of high-dimensional data. As an offline model alternative to finite element methods, the proposed approach holds promise for efficient and real-time prediction of the mechanical behavior of shallow foundations under loading.

关键词：

来源：评论

学校读者我要写书评

暂无评论

FMCCM: A Fast Maximum Consistent Color Mapping of 3D Point Cloud for Intelligent Recognition of Rock Discontinuity Plane via Deep Learning 5th

FMCCM: A Fast Maximum Consistent Color Mapping of 3D Point C...

引用

5th International Conference on Information Technology in Geo-engineering, ICITG 2024

作者： Zhang, Keshen Wu, Wei Zhu, Hehua College of Civil Engineering Tongji University Shanghai200092 China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji University Shanghai200092 China State Key Laboratory of Disaster Reduction in Civil Engineering Tongji University Shanghai200092 China

ISBN: (纸本)9783031765278

Discontinuity recognition is important for the description of rock discontinuities. The accuracy and efficiency of traditional recognition methods based on 3D point clouds are often affected by manual parameter settings during the process. This paper proposes a deep learning intelligent discontinuity recognition method based on a fast, maximum consistent color mapping of the point cloud. The main idea is to quickly assign different colors to different discontinuity planes according to the normal vector while keeping the color within the same discontinuity plane as uniform as possible. Then, the recognition of discontinuities in 3D point clouds is converted to the recognition of discontinuities with different colors in 2D images. Sharp points of discontinuities are also detected to facilitate the recognition. The Mask R-CNN neural network is used to train and recognize discontinuities in 2D images. Finally, the recognized 2D discontinuities are mapped back to the 3D point cloud. The results show the proposed method can achieve intelligent recognition of rock discontinuity with high efficiency and full automation without manual intervention during the process, and the recognition effect is more consistent with manual judgment than traditional methods. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.

关键词： Mapping

来源：评论

学校读者我要写书评

暂无评论

Mechanical Properties and Microstructure Characteristics of Submerged Cement-Based Stabilized Marine Soft Clay Enhanced with ISS and PAM

引用

Journal of Ocean University of China 2025年第2期24卷 387-403页

作者： ZHU Chenghao YU Peng GUO Zixian WANG Qigang LIU Hongjun Key Laboratory of Shandong Province for Marine Environment and Geological Engineering Ocean University of ChinaQingdao 266100China College of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China Key Laboratory of Geological Safety of Coastal Urban Underground Space Ministry of Natural ResourcesQingdao 266101China Qingdao Geotechnical Investigation and Surveying Research Institute Qingdao Municipal Natural Resources and Planning BureauQingdao 266032China Key Laboratory of Marine Environment and Ecology Ministry of EducationOcean University of ChinaQingdao 266100China

The traditional cement-based stabilization cannot effectively stabilize the marine soft clay under submerged *** order to solve this problem,the enhancement of cement-stabilized marine soft clay was investigated in this study by adding the ionic soil stabilizer(ISS)and polyacrylamide(PAM).For this purpose,varying contents of ISS and PAM(ISS-P)were added into cement-stabilized marine soft clay and subjected to curing under submerged *** limits tests,direct shear tests,unconfined compression strength(UCS)tests,water-stability tests,scanning electron microscopy analysis,and X-ray diffraction analysis were carried *** results show that using 1.8%ISS and 0.9%PAM as the optimal ratio,the cohesion,internal friction angle,UCS,and water-stability of the samples increased by 1.2.7%,1..4%,1.6.5%,and 368.5% compared to the cement-stabilized soft clay after 28 *** increment in soil cohesion with increasing ISS-P content was more apparent than that in the internal friction *** combined action of ion exchange attraction and electrostatic adsorption altered the failure characteristics of the samples,resulting in localized micro-cracking and multiple failure *** the content of ISS-P strengthened the skeletal structure of soil,reduced inter-particle spacing,and enhanced the ***,ISS promotes the hydration of cement and compensates for the inhibitory effect of PAM on early cement ***-P can effectively enhance the strength and stability of submerged cement-based stabilized marine soft clay.

关键词： ionic soil stabilizer polyacrylamide marine soft clay mechanical property microstructure

来源：评论

学校读者我要写书评

暂无评论

Fe/N modified porous carbon nanofibers with encapsulated FeCo nanoparticles for efficient electrocatalytic nitrate reduction to ammonia

引用

Journal of Environmental Sciences (China) 2025年 157卷 90-99页

作者： Chen, Jiayu Wu, Anni Li, Jixiang Hong, Chengyi Tang, Wenxiang Zheng, Hu Teng, Wei State Key Laboratory for of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University Shanghai 200092 China Department of Geotechnical Engineering College of Civil Engineering Tongji University Shanghai 200092 China Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 200120 China University of Chinese Academy of Sciences Beijing 100049 China Department of Civil and Environmental Engineering Carnegie Mellon University PittsburghPA15213 United States Key Laboratory of Geotechnical and Underground Engineering of the ministry of Education State Key Laboratory of Disaster Reduction in Civil Engineering Tongji University Shanghai 200092 China

The efficient electrocatalytic nitrate (NO3−) reduction to ammonia (NRA) offers a sustainable alternative for both environmental remediation and ammonia synthesis. Developing advanced electrocatalysts with rationally designed spatial arrangement of active sites and optimizing the synergetic effect among components are crucial for high efficiency and selectivity. Herein, we present Fe/N active sites decorated on porous carbon nanofibers (CNFs) with encapsulated FeCo nanoparticles (FeCo@CNFs-Fe/N) as electrocatalysts for NRA. The FeCo@CNFs-Fe/N catalyst demonstrates exceptional performance, achieving a high ammonia yield of 498.1. μmol/(h·gcat). Meanwhile, the enhanced reduction activity, especially the reduction in overpotential by 0.565 V, is 3–1. times higher than that of FeCo-encapsulated and Fe/N-modified CNFs-based catalysts. The enhanced catalytic activity is attributed to the efficient structure design and optimized spatial distribution of active sites, which enhance the electron transfer rate and decrease the reaction energy barrier. Mechanistic studies reveal that the synergetic effect between encapsulated nanoparticles and surface-modified Fe/N sites plays a crucial role in promoting efficient nitrate adsorption and selective ammonia production. These findings highlight the potential of strategically engineered CNF-based composites for nitrate reduction and other advanced electrocatalytic applications. © 2025

关键词： Carbon nanofibers

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：