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LSSVM-based approach for refining soil failure criteria and calculating safety factor of slopes

Shiguo XIAO; Shaohong LI

《结构与土木工程前沿（英文）》 2022年 第16卷 第7期   页码 871-881 doi: 10.1007/s11709-022-0863-8

摘要： The failure criteria of practical soil mass are very complex, and have significant influence on the safety factor of slope stability. The Coulomb strength criterion and the power-law failure criterion are classically simplified. Each one has limited applicability owing to the noticeable difference between calculated predictions and actual results in some cases. In the work reported here, an analysis method based on the least square support vector machine (LSSVM), a machine learning model, is purposefully provided to establish a complex nonlinear failure criterion via iteration computation based on strength test data of the soil, which is of more extensive applicability to many problems of slope stability. In particular, three evaluation indexes including coefficient of determination, mean absolute percentage error, and mean square error indicate that fitting precision of the machine learning-based failure criterion is better than those of the linear Coulomb criterion and nonlinear power-law criterion. Based on the proposed LSSVM approach to determine the failure criterion, the limit equilibrium method can be used to calculate the safety factor of three-dimensional slope stability. Analysis of results of the safety factor of two three-dimensional homogeneous slopes shows that the maximum relative errors between the proposed approach and the linear failure criterion-based method and the power-law failure criterion-based method are about 12% and 7%, respectively.

关键词： slope stability     safety factor     failure criterion     least square support vector machine    

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基于可靠指标的稳定安全系数探讨

童小龙,方志

《中国工程科学》 2012年 第14卷 第11期   页码 44-48

摘要：

桥梁结构当第一类稳定安全系数取4时，能否保证结构在更可能出现的第二类失稳发生时的可靠指标达到目标可靠指标值得研究。对单层单跨刚架桥分别进行了第一类和第二类稳定计算，以第一类稳定计算得到的临界荷载，取第一类稳定安全系数为4，采用一次可靠度方法编制程序得出可靠指标。进而采用第一类稳定可靠指标计算时的荷载效应和第二类临界荷载来计算第二类可靠指标。根据可靠指标探讨结构稳定安全系数取值的合理性。在此基础上，对两类稳定临界荷载进行了参数分析，研究临界荷载的变化对可靠指标的影响。结果表明：稳定分析应区分失稳状态，第一类稳定安全系数取4，但当结构发生第二类失稳时，有些情况下不足以保证可靠指标达到目标可靠指标。

关键词： 稳定安全系数     可靠指标     刚架桥    

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信息安全系统观

林代茂

《中国工程科学》 2007年 第9卷 第8期   页码 21-25

摘要：

给出了信息安全的三层涵义，指出信息安全学科是自然科学与社会科学的融合体。从社会工程角度给出系统的概念，从部件、接缝、人员、环境四方面探讨了系统与信息安全的关系，提出了信息安全设计的必要步骤,并以通信系统为例分析了影响信息安全的因素。

关键词： 信息安全     安全系数     信息隐藏     接缝     威胁    

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Evaluation and prediction of slope stability using machine learning approaches

《结构与土木工程前沿（英文）》 2021年 第15卷 第4期   页码 821-833 doi: 10.1007/s11709-021-0742-8

摘要： In this paper, the machine learning (ML) model is built for slope stability evaluation and meets the high precision and rapidity requirements in slope engineering. Different ML methods for the factor of safety (FOS) prediction are studied and compared hoping to make the best use of the large variety of existing statistical and ML regression methods collected. The data set of this study includes six characteristics, namely unit weight, cohesion, internal friction angle, slope angle, slope height, and pore water pressure ratio. The whole ML model is primarily divided into data preprocessing, outlier processing, and model evaluation. In the data preprocessing, the duplicated data are first removed, then the outliers are filtered by the LocalOutlierFactor method and finally, the data are standardized. 11 ML methods are evaluated for their ability to learn the FOS based on different input parameter combinations. By analyzing the evaluation indicators R 2, MAE, and MSE of these methods, SVM, GBR, and Bagging are considered to be the best regression methods. The performance and reliability of the nonlinear regression method are slightly better than that of the linear regression method. Also, the SVM-poly method is used to analyze the susceptibility of slope parameters.

关键词： slope stability     factor of safety     regression     machine learning     repeated cross-validation    

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以土体应力状态计算边坡安全系数的方法

王国体

《中国工程科学》 2006年 第8卷 第12期   页码 80-84

摘要：

土坡的稳定分析一直是沿着条分法的思路发展的。由于对土体应力状态条件的忽视和条分法本身的缺陷，使得条分法得到的安全系数在工程中的应用面临激烈的挑战。土体不同条件下的应力状态表现为K0效应和变化，它对坡体的安全度影响不可忽视。笔者以考虑土体应力状态为条件，应用土的库伦强度定律和摩尔-库伦准则，推导出平面土坡的安全系数计算公式，与条分法的安全系数对比结果说明这种方法具有概念明确、计算简便、定性可靠的重要特点，可以直接提供于工程应用和参考。

关键词： 侧应力系数K0     初始应力状态     稳定安全系数公式    

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Evaluation of the stability of terraced slopes in clayey gravel soil using a novel numerical technique

《结构与土木工程前沿（英文）》 2023年 第17卷 第5期   页码 796-811 doi: 10.1007/s11709-023-0922-9

摘要： Conventional geotechnical software limits the use of the strength reduction method (SRM) based on the Mohr–Coulomb failure criterion to analyze the slope safety factor (SF). The use of this constitutive model is impractical for predicting the behavior of all soil types. In the present study, an innovative numerical technique based on SRM was developed to determine SF using the finite element method and considering the extended Cam–clay constitutive model for clayey gravel soil as opposed to the Mohr–Coulomb model. In this regard, a novel user subroutine code was employed in ABAQUS to reduce the stabilizing forces to determine the failure surfaces and resist and drive shear stresses on a slope. After validating the proposed technique, it was employed to investigate the performance of terraced slopes in the context of a case study. The impacts of geometric parameters and different water table elevations on the SF were examined. The results indicated that an increase in the upper and lower slope heights led to a decrease in SF, and a slight increase in the horizontal offset led to an increase in the SF. Moreover, when the water table elevation was lower than the toe of the terraced slope, the SF increased because of the increase in the uplift force as a resistant component.

关键词： terraced slope     safety factor     finite element method     ABAQUS     extended Cam–clay    

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Effect of a less permeable stronger soil layer on the stability of non-homogeneous unsaturated slopes

Nabarun DEY, Aniruddha SENGUPTA

《结构与土木工程前沿（英文）》 2020年 第14卷 第6期   页码 1462-1475 doi: 10.1007/s11709-020-0674-8

摘要： Slope failure occurs due to an increase in the saturation level and a subsequent decrease in matric suction in unsaturated soil. This paper presents the results of a series of centrifuge experiments and numerical analyses on a 55° inclined unsaturated sandy slope with less permeable, stronger silty sand layer inclusion within it. It is observed that a less permeable, stronger silty sand layer in an otherwise homogeneous sandy soil slope hinders the infiltration of water. The water content of the slope just above the stronger layer increases significantly, compared to elsewhere. No shear band is found to initiate in a homogeneous sandy soil slope, whereas for a non-homogeneous slope, they initiate just above the less pervious, stronger layer. A discontinuity of the shear zone is also observed for the case of a non-homogeneous soil slope. The factor of safety of a non-homogeneous, unsaturated soil slope decreases because of the less permeable, stronger layer. It decreases significantly if this less permeable, stronger soil layer is located near the toe of the slope.

关键词： non-homogeneous slope     stronger soil layer     factor of safety     centrifuge model test     unsaturated soils    

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基于拉索安全评估的普通斜拉桥和矮塔斜拉桥结构冗余度对比研究 Article

Khawaja Ali, Hiroshi Katsuchi, Hitoshi Yamada

《工程（英文）》 2021年 第7卷 第1期   页码 111-123 doi: 10.1016/j.eng.2020.07.021

摘要：

本研究基于斜拉桥和矮塔斜拉桥的拉索安全性评估，为比较斜拉桥和矮塔斜拉桥提供了新的观点。由于二者都使用拉索，人们通常认为这两种类型的桥梁具有相同的结构。但是，国际桥梁设计标准规定了二者各自的拉索安全系数。为了纠正这一误解，本研究通过考虑各种异常因素和破坏因素（如过载、钢索损耗和钢索腐蚀）的影响，对在疲劳和极限状态下的拉索的安全系数进行了比较。本研究的主要目的是解释两种类型桥梁之间的结构差异，并通过采用确定性和非确定性方法来评估其结构冗余。为了实现这一目标，根据日本现行的拉索设计指南，本文建立了两座桥的三维模型。在达到桥梁模型的平衡状态之后，以参数化方式对拉索的不同安全系数进行了静态分析。最后，采用一阶可靠性方法和蒙特卡洛方法确定了拉索的可靠性指标。分析结果表明，在相同的荷载条件下，斜拉桥和矮塔斜拉桥在不同安全系数下具有不同的结构冗余度。此外，随着拉索的安全系数的增加，其结构上的冗余大大增加。

关键词： 斜拉桥     矮塔斜拉桥     冗余     拉索     安全系数     可靠性分析    

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论混凝土坝的几个重要问题

朱伯芳

《中国工程科学》 2006年 第8卷 第7期   页码 21-29

摘要：

目前我国在建混凝土坝的高度、数量、规模均居世界第一位，文章就混凝土坝技术的几个重要问题进行讨论：（1）结束“无坝不裂”历史的关键技术；（2）应用氧化镁混凝土筑坝的两种指导思想和两种实践结果；（3）混凝土强度等级应用于混凝土坝欠妥，坝工混凝土仍以采用混凝土标号为宜；（4）我国特高拱坝的抗压安全系数偏低，应适当提高。（5）拱坝有限元等效应力问题。

关键词： 混凝土坝     裂缝     混凝土标号     抗压安全系数     有限元等效应力    

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基于最大熵原理的复合形法及其在边坡稳定分析中的应用

李亮,迟世春,林皋

《中国工程科学》 2005年 第7卷 第4期   页码 64-68

摘要：

将最大熵原理应用于基本复合形法的优化计算中，旨在提高算法的寻优成功率。具体步骤为：选取复形中熵最大的顶点为寻优点；在复形其余各点的加权中心点与寻优点的连线上，搜索比寻优点改善的新顶点；并替换掉寻优点构成新的复形；如此迭代直至复形中的信息被完全利用。采用基本复合形法和基于最大熵原理的复合形法对两个复杂土坡的最小安全系数进行了搜索，结果表明基于最大熵原理的复合形法的全局搜索能力有了明显改善。

关键词： 熵     复合形法     边坡稳定     安全系数    

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苏通长江大桥施工阶段结构稳定性研究

赵雷,李乔,张鸿,卜一之

《中国工程科学》 2009年 第11卷 第3期   页码 81-84

摘要：

按照苏通长江大桥实际的施工过程及其施工荷载分布，考虑施工过程的影响，建立全桥空间组合结构计算模型，用有限元法研究了主桥斜拉桥自索塔施工开始直到全桥合龙的各施工阶段的结构稳定安全系数及其失稳模态，对主桥钢箱梁架设施工过程中的结构稳定行为给出了综合评价。

关键词： 苏通大桥斜拉桥     施工过程     结构稳定     安全系数     有限元法    

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Quantitatively assessing the pre-grouting effect on the stability of tunnels excavated in fault zones with discontinuity layout optimization: A case study

Xiao YAN, Zizheng SUN, Shucai LI, Rentai LIU, Qingsong ZHANG, Yiming ZHANG

《结构与土木工程前沿（英文）》 2019年 第13卷 第6期   页码 1393-1404 doi: 10.1007/s11709-019-0563-1

摘要： Pre-grouting is a popular ground treatment strategy utilized to enhance the strength and stability of strata during the excavation of a tunnel through a fault zone. Two important questions need to be answered during such an excavation. First, how should the grouting size be determined? Second, when should excavation begin after grouting? These two questions are conventionally addressed through empirical experience and standard criteria because a reliable quantitative approach, which would be preferable, has not yet been developed. To address these questions, we apply a recently proposed numerical approach known as discontinuity layout optimization, an efficient node-based upper bound limit analysis method. A case study is provided utilizing a tunnel located in a stratum characterized by complicated geological conditions, including soft soil and a fault zone. The factor of safety is used to quantitatively assess the stability of the tunnel section. The influences of the grouted zone thickness and the time-dependent material properties of the grouted zone on the stability of the tunnel section are evaluated, thereby assisting designers by quantitatively assessing the effects of pre-grouting.

关键词： pre-grouting     stability analysis     factor of safety     discontinuity layout optimization    

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Urban design based on public safety-Discussion on safety-based urban design

Kaizhen CAI, Jianguo WANG

《结构与土木工程前沿（英文）》 2009年 第3卷 第2期   页码 219-227 doi: 10.1007/s11709-009-0023-4

摘要： Because of public safety problems in construction of urban surroundings, this paper expounds the necessity of the study on public safety-based urban design in perspective of modern city. It brings forward the concept of safety-based urban design and attempts to explore the basic connotation and contents with framework for studies.

关键词： urban public safety     urban design     safety-based urban design    

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Role of the forkhead transcription factor FOXO-FOXM1 axis in cancer and drug resistance

null

《医学前沿（英文）》 2012年 第6卷 第4期   页码 376-380 doi: 10.1007/s11684-012-0228-0

摘要：

The forkhead transcription factors FOXO and FOXM1 have pivotal roles in tumorigenesis and in mediating chemotherapy sensitivity and resistance. Recent research shows that the forkhead transcription factor FOXM1 is a direct transcriptional target repressed by the forkhead protein FOXO3a, a vital downstream effector of the PI3K-AKT-FOXO signaling pathway. Intriguingly, FOXM1 and FOXO3a also compete for binding to the same gene targets, which have a role in chemotherapeutic drug action and sensitivity. An understanding of the role and regulation of the FOXO-FOXM1 axis will impact directly on our knowledge of chemotherapeutic drug action and resistance in patients, and provide new insights into the design of novel therapeutic strategy and reliable biomarkers for prediction of drug sensitivity.

关键词： FOXO3a     FOXM1     transcription factor     cancer     drug resistance     tumorigenesis    

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中国食品安全科技发展方向讨论

魏益民,吴永宁,周乃元,潘家荣

《中国工程科学》 2005年 第7卷 第11期   页码 1-4

摘要：

从发展国家食品安全战略，强化国家食品安全科技的角度，提出中国食品安全科技优先发展的四大方向，即风险分析是食品安全科技战略的首选领域；“从农田到餐桌”整体控制体系是食品安全全程控制技术和操作规范的理论基础，是实施食品安全管理的重要技术手段；检测监测技术是预警、预防、应急的技术依据，应集中力量开发一批内控和标准检验必须的快速检测技术和标准检测技术；以政府、生产者、消费者为责任人主体的管理理念是食品安全管理的基本原则，食品链上的所有责任人应在保障食品质量和安全的问题上主动承担责任。

关键词： 食品安全     科技     战略     发展方向    

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标题 作者 时间 类型 操作

LSSVM-based approach for refining soil failure criteria and calculating safety factor of slopes

Shiguo XIAO; Shaohong LI

期刊论文

基于可靠指标的稳定安全系数探讨

童小龙,方志

期刊论文

信息安全系统观

林代茂

期刊论文

Evaluation and prediction of slope stability using machine learning approaches

期刊论文

以土体应力状态计算边坡安全系数的方法

王国体

期刊论文

Evaluation of the stability of terraced slopes in clayey gravel soil using a novel numerical technique

期刊论文

Effect of a less permeable stronger soil layer on the stability of non-homogeneous unsaturated slopes

Nabarun DEY, Aniruddha SENGUPTA

期刊论文

基于拉索安全评估的普通斜拉桥和矮塔斜拉桥结构冗余度对比研究

Khawaja Ali, Hiroshi Katsuchi, Hitoshi Yamada

期刊论文

论混凝土坝的几个重要问题

朱伯芳

期刊论文

基于最大熵原理的复合形法及其在边坡稳定分析中的应用

李亮,迟世春,林皋

期刊论文

苏通长江大桥施工阶段结构稳定性研究

赵雷,李乔,张鸿,卜一之

期刊论文

Quantitatively assessing the pre-grouting effect on the stability of tunnels excavated in fault zones with discontinuity layout optimization: A case study

Xiao YAN, Zizheng SUN, Shucai LI, Rentai LIU, Qingsong ZHANG, Yiming ZHANG

期刊论文

Urban design based on public safety-Discussion on safety-based urban design

Kaizhen CAI, Jianguo WANG

期刊论文

Role of the forkhead transcription factor FOXO-FOXM1 axis in cancer and drug resistance

null

期刊论文

中国食品安全科技发展方向讨论

魏益民,吴永宁,周乃元,潘家荣

期刊论文