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可视化软土隧道模型试验相似材料的配置及其物理力学特性研究

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现代隧道技术 2024年第4期61卷 202-209页

作者：何晟亚李亮李恒一张建经叶亮文海家段虎辰谢朋广州地铁设计研究院股份有限公司广州510010 西南交通大学土木工程学院成都610031 重庆大学土木工程学院重庆400045 海南大学土木建筑工程学院海口570228

可视化的模型试验是明晰软土隧道开挖诱发连锁事故触发机理的有效手段,而合理配比的相似材料是保证模型试验可靠性的关键。选取正十二烷、15#白油、熔融石英砂和纳米级白炭黑配置透明软土相似材料。通过密度与含油率测试、标准固结试验... 详细信息

可视化的模型试验是明晰软土隧道开挖诱发连锁事故触发机理的有效手段,而合理配比的相似材料是保证模型试验可靠性的关键。选取正十二烷、15#白油、熔融石英砂和纳米级白炭黑配置透明软土相似材料。通过密度与含油率测试、标准固结试验和固结快剪试验,开展配制材料力学和变形特性分析。研究结果表明:相似材料的密度在1.30~1.59 g/cm^(3)之间,含油率在36.13%~124.71%之间,初始孔隙比在0.70~2.34之间,压缩系数在0.09~1.04 MPa^(-1)之间,压缩模量在0.96~20.11 MPa之间,黏聚力在2.3~31 kPa之间,内摩擦角在14.82°~27.07°之间时,与天然软土相似。试样的e-p曲线均具有较为明显的“上凹型”,e-lgp曲线均呈近似直线下降趋势。每组配比的固结系数在7.87×10^(-4)~2.02×10^(-2)cm^(2)/s之间,符合天然软土固结系数取值范围。透明软土归一化后的剪应力-剪切位移曲线与天然软土的相同,均呈现应变硬化的特点。

关键词：软土隧道室内试验透明相似材料配置方法物理力学特性

A prediction model for horizontal run-out distance of landslides triggered by Wenchuan earthquake

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Earthquake Engineering and Engineering Vibration 2013年第2期12卷 201-208页

作者： Yang Changwei zhang jianjing zhang Ming Department of Civil Engineering Southwest Jiaotong University Key Laboratory of High-speed Railway Engineering (Southwest Jiaotong University) Ministry of Education Zhengzhou Zhonghe Geotechnical Engineering Co. LTD

The peak ground acceleration （PGA）, the volume of a sliding mass V, the height of a mountain HL and the slope angle θ of a mountain are four important parameters affecting the horizontal run-out distance of a landslide L. Correlations among them are studied statistically based on field investigations from 67 landslides triggered by the ground shaking and other factors during the Wenchuan earthquake, and then a prediction model for horizontal run-out distance L is developed in this study. This model gives due consideration to the implications of the above four parameters on the horizontal run-out distance L and the validity of the model is verified by the Donghekou and Magong Woqian landslides. At the same time, the advantages of the model are shown by comparing it with two other common prediction methods. The major findings drawn from the analyses and comparisons are：（1） an exponential relationship exists between L and log V, L and log HL, L and log PGA separately, but a negative exponential relationship exists between L and log tan0, which agrees with the statistical results; and （2） according to the analysis results of the relative relationship between the height of a mountain （H） and the place where the landslides occur, the probabilities at distances of2H/3-H, H/3-2H/3, and O-H/3 are 70.8%, 15.4%, and 13.8%, respectively, revealing that most landslides occurred at a distance of H/2-H. This prediction model can provide an effective technical support for the prevention and mitigation of landslide hazards.

关键词： Wenchuan earthquake landslides run-out distance prediction model relationship

Deep Learning-Driven Data Curation and Model Interpretation for Smart Manufacturing

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Chinese Journal of Mechanical Engineering 2021年第3期34卷 52-72页

作者： jianjing zhang Robert X.Gao Department of Mechanical and Aerospace Engineering Case Wester Reserve UniversityClevelandOH 44106-7222USA

Characterized by self-monitoring and agile adaptation to fast changing dynamics in complex production environments,smart manufacturing as envisioned under Industry 4.0 aims to improve the throughput and reliability of production beyond the *** the widespread application of deep learning(DL)has opened up new opportunities to accomplish the goal,data quality and model interpretability have continued to present a roadblock for the widespread acceptance of DL for real-world *** has motivated research on two fronts:data curation,which aims to provide quality data as input for meaningful DL-based analysis,and model interpretation,which intends to reveal the physical reasoning underlying DL model outputs and promote trust from the *** paper summarizes several key techniques in data curation where breakthroughs in data denoising,outlier detection,imputation,balancing,and semantic annotation have demonstrated the effectiveness in information extraction from noisy,incomplete,insufficient,and/or unannotated *** highlighted are model interpretation methods that address the“black-box”nature of DL towards model transparency.

关键词： Deep learning Data curation Model interpretation

Strength reduction factors for seismic analyses of buildings exposed to near-fault ground motions

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Earthquake Engineering and Engineering Vibration 2011年第2期10卷 195-209页

作者： Qu Honglue zhang jianjing J.X. Zhao School of Civil Engineering Southwest Jiaotong University Chengdu 610031 China Institute of Geological ＆ Nuclear Sciences PO Box 30-368 Lower Hutt New Zealand

To estimate the near-fault inelastic response spectra, the accuracy of six existing strength reduction factors （R） proposed by different investigators were evaluated by using a suite of near-fault earthquake records with directivity-induced pulses. In the evaluation, the force-deformation relationship is modelled by elastic-perfectly plastic, bilinear and stiffness degrading models, and two site conditions, rock and soil, are considered. The R-value ratio （ratio of the R value obtained from the existing R-expressions （or the R-p-T relationships） to that from inelastic analyses） is used as a measurement parameter. Results show that the R-expressions proposed by Ordaz ＆ Perez-Rocha are the most suitable for near-fault ground motions, followed by the Newmark ＆ Hall and the Berrill et al. relationships. Based on an analysis using the near-fault ground motion dataset, new expressions of R that consider the effects of site conditions are presented and verified.

关键词： strength reduction factors near-fault ground motion response spectra force-deformation relationship

Bone marrow edema in a postpartum female following ankle sprain: a case report

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World Journal of Emergency Medicine 2024年第4期15卷 325-327页

作者： Peng zhang Junjie zhang Peng Chen jianjing Lin Jiang Guo Weixuan Liu Zhiwen Luo Qing Wang Xintao zhang Department of Sports Medicine Peking University Shenzhen HospitalShenzhen 518000China Department of Sports Medicine Huashan HospitalFudan UniversityShanghai 200040China Department of Orthopaedics Kunshan Hospital of Traditional Chinese MedicineKunshan 215300China

Bone marrow edema(BME)is characterized by an accumulation of interstitial fluid within the bone marrow,the cancellous,hematopoietic compartment within bones.[1]BME is divided into two principal categories:idiopathic or primary BME,with an unknown etiology,and secondary BME,which occurs as a result of an identifiable underlying pathology.[2]Although the prevalence of BME is not limited to specific demographic parameters,it shows a predilection for males or individuals assigned male at birth,predominantly aged between the ages of 30 and 60 years,especially in cases of bone marrow edema syndrome(BMES),a rare idiopathic variant.[3]The etiological spectrum of BME is diverse,including oncological entities(such as acute myeloid leukemia and osteosarcoma),degenerative diseases(such as osteoarthritis),infectious processes(osteomyelitis),ischemic conditions(avascular necrosis),metabolic dysfunctions(osteoporosis),inflammatory disorders(rheumatoid arthritis),and traumatic injuries(such as stress fractures).[1,2]Clinically,BME primarily manifests as localized pain,often accompanied by joint effusion and warmth near the affected *** protocols typically include physical examination,serological assays,bone marrow biopsies,dual-energy X-ray absorptiometry(DEXA)scans,magnetic resonance imaging(MRI),and ultrasonography,with computed tomography(CT)scans and radiographs being less effective.

关键词： edema injuries female

Characteristics of seismic responses at liquefied and non-liquefied sites with same site conditions

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Journal of Modern Transportation 2011年第2期19卷 134-142页

作者： jianjing zhang Changwei YANG The Institute of Geological ＆ Nuclear Science Lower Hutt 5040 New Zealand School of Civil Engineering Southwest Jiaotong University Chengdu 610031 China

To understand the characteristics of seismic response at liquefied sites, a liquefiable site and a non-liquefiable site were selected, separated by about 500 m and having the same site conditions as Class D in the National Earthquake Hazards Reduction Program （NEHRP）. A suite of earthquake records on rock sites are selected and scaled to the spectrum of the Joyner, Boore, and Fumal （JBF） attenuation model for a magnitude 7.5 earthquake at a distance of 50 km. The scaled records were then used to excite the two sites. The effect of pore-water pressure was investigated using the effective stress analysis method, and nonlinear soil behavior was modeled by a soil bounding surface model. Comparisons for spectra, peak ground acceleration （PGA）, peak ground displacement （PGD） and permanent displacement were performed. Results show that the mean ground response spectrum at the non-liquefied site is close to the estimated ground response spectrum from the JBF model, but the mean ground response spectrum at the liquefied site is much lower than the estimated ground response spectrum from the JBF model for periods of up to 1.3 s. The mean PGA at the non-liquefied site is about 1.6-1.7 times as large as that at the liquefied site, but the mean peak ground displacement （PGD） at the non-liquefied site has a slight difference with that at the liquefied site. The mean permanent displacements at the liquefied site are larger than those at the non-liquefied site, particularly at the liquefied layer.

关键词： seismic responses liquefied and non-liquefied excessive pore-water pressure

Analysis of the Effects of Slope Geometry on the Dynamic Response of a Near-field Mountain from the Wenchuan Earthquake

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Journal of Mountain Science 2010年第4期7卷 353-360页

作者： XIAO Shiguo FENG Wenkai zhang jianjing Department of Geoteehnical Engineering Southwest Jiaotong University Chengdu 610031 China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 610059 China Department of C-eoteehnical Engineering Southwest Jiaotong University Chengdu 610031 China

Fourier spectra and acceleration response spectra of near-field acceleration records of the 2008 Wenchuan Earthquake have been *** fundamental frequencies(or predominant periods) were ***,the natural frequencies of a range of slopes with different geometric characteristics,such as height,slope ratio,and pattern,were *** seismic responses of the slopes were compared,and the variability of seismic response with the above geometric elements was *** show that if slope height increases,and provided that other conditions are unchanged,the natural frequency of the first mode of a doublesurface slope will change as a power ***,natural frequencies will diminish(based on a parabolic function) as the slope angle becomes *** the surface pattern and the number of surfaces on a slope can have a great impact on the seismic response of the ***,within a certain range of slope heights or angles,either height or angle will also greatly influence the variability of the seismic *** results of this research will be helpful to understanding seismic dynamic response features and explaining the ways that slope stability can be affected by earthquakes.

关键词：地震反应动力响应分析近场汶川加速度反应谱边坡尺寸形状

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土体冻融特性试验研究现状与思考

岩石力学与工程学报 2022年第6期41卷 1267-1284页

作者：周永毅张建经闫世杰牛家永谢强西南交通大学土木工程学院四川成都610031

冻融试验是获取冻土物理力学参数、评估冻土工程特性的重要手段。从冻土水热参数、力学参数、冻胀机制和融沉机制4个方面对土体冻融特性试验研究进行综述,对主要水热力参数的试验方法和试验设备进行汇总说明,对理论模型的发展过程及试... 详细信息

冻融试验是获取冻土物理力学参数、评估冻土工程特性的重要手段。从冻土水热参数、力学参数、冻胀机制和融沉机制4个方面对土体冻融特性试验研究进行综述,对主要水热力参数的试验方法和试验设备进行汇总说明,对理论模型的发展过程及试验验证进行归纳整理。试验装置的变温控制性能是影响冻土试验数据质量的重要因素,但当前高精度冷却液循环控温设备的国产化程度较低,高性能冻融试验系统仍主要依赖进口。因此在开展冻土试验和理论研究的同时,对于试验设备的研发工作同样需引起重视。由神经网络–PID算法和热电制冷模块组成的固态控温系统可以解决试验装置的变温控制问题。固态控温系统的高变温控制性能具备模拟复杂冻结过程的能力。将其与新型传感技术结合,如光纤压力传感技术、线阵CCD扫描成像技术,可以为冻土研究提供新的试验方案,以此促进土体冻融机制研究,为我国寒区工程建设提供参考。

关键词：土力学冻融试验控温技术固态制冷变温控制冻土

汶川地震中国道G213左侧某典型高山河谷场地地震滑坡响应分析

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岩石力学与工程学报 2013年第7期32卷 1467-1475页

作者：杨长卫张建经西南交通大学土木工程学院四川成都610031

以国道G213左侧一处包含河谷地形的高陡边坡为原型,采用新型离散元计算方法——基于连续模型的离散元方法(CDEM),对高烈度地震作用下高陡边坡上的堆积体滑坡由变形累计到破坏滑动的全过程进行模拟,并结合振动台试验结果,对该高陡边坡上... 详细信息

以国道G213左侧一处包含河谷地形的高陡边坡为原型,采用新型离散元计算方法——基于连续模型的离散元方法(CDEM),对高烈度地震作用下高陡边坡上的堆积体滑坡由变形累计到破坏滑动的全过程进行模拟,并结合振动台试验结果,对该高陡边坡上堆积体的地震滑坡响应进行研究。研究结果表明,在地震力和重力作用下,堆积体顶部先出现应力集中,造成堆积体沿基岩–堆积体结构面后缘产生变形,进而造成该处出现拉伸、剪切破坏点,之后随着地震动的持续,基岩–堆积体结构面上的剪切破坏点逐渐向堆积体中前部的锁固段扩展,同时伴随着堆积体表面拉伸破坏点的增加,最终造成锁固段发生渐进性破坏,堆积体从剪出口滑出形成滑坡。滑塌发生的时间与地震动峰值加速度到达的时间同步或稍微有所滞后。在高陡边坡地形中,以输入地震波为基准,不论是坡面还是坡体内,不同位置的峰值加速度沿坡高均有所放大,表现为竖向峰值加速度的放大效应>水平峰值加速度的放大效应,坡面峰值加速度的放大效应>坡体内峰值加速度的放大效应。在河谷地形中,以输入波为基准,不论是河床还是河岸两侧的斜坡,不同位置的峰值加速度沿高程均具有不同程度的放大;河谷对加速度放大效应的影响具有一定范围,且在该范围内水平加速度的放大效应>竖向加速度的放大效应,与坡面处加速度的放大效应刚好相反;加速度的放大效应具有一定的方向性,且该方向性与河岸两侧斜坡的坡度有关;加速度放大效应在河谷底部的分布具有不均匀性,距离河岸越近,加速度放大效应越强烈。

关键词：边坡工程基于连续模型的离散元方法高山河谷地震滑坡响应峰值加速度