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Multivariate adaptive regression splines analysis for 3D slope stability in anisotropic and heterogenous clay

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第4期15卷 1052-1064页

作者： Jim shiau Van Qui lai Suraparb Keawsawasvong School of Civil Engineering and Surveying University of Southern QueenslandToowoombaQueensland4350Australia Faculty of Civil Engineering Ho Chi Minh City University of Technology(HCMUT)268 Ly Thuong Kiet StreetDistrict 10Ho Chi Minh CityViet Nam Vietnam National University Ho Chi Minh City(VNU-HCM) Linh Trung WardThu Duc DistrictHo Chi Minh CityViet Nam Department of Civil Engineering Thammasat School of EngineeringThammasat UniversityPathumthaniBangkok12120Thailand

Little research can be found in relation to the stability of anisotropic and heterogenous soils in three *** this paper,we propose a study on the three-dimensional(3D)undrained slopes in anisotropic and heterogenous clay using advanced upper and lower bounds finite element limit analysis(FELA).The obtained stability solutions are normalized,and presented by a stability number that is a function of three geometrical ratios and two material ratios,*** ratio,length ratio,slope angle,shear strength gradient ratio and anisotropic strength *** results are compared with experimental data in the literature,and charts are presented to cover a wide range of design *** the multivariate adaptive regression splines(MARS)analysis,the respective influence and sensitivity of each design parameter on the stability number and the failure mechanism are *** empirical equation is also developed to effectively estimate the stability number.

关键词： 3D undrained slope Limit analysis Anisotropy Heterogeneity

Undrained stability of pit-in-pit braced excavations under hydraulic uplift

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Underground Space 2022年第6期7卷 1139-1155页

作者： Fengwen lai Fuquan Chen Songyu Liu Suraparb Keawsawasvong Jim shiau Institute of Geotechnical Engineering Southeast UniversityNanjing 211189China Faculty of Civil Engineering and Geosciences Delft University of TechnologyPO-box 50482628 CN Delft/2600 GA DelftThe Netherlands College of Civil Engineering Fuzhou UnivFuzhou 350116China Department of Civil Engineering Thammasat School of EngineeringThammasat UnivPathumthani 12120Thailand School of Engineering University of Southern QueenslandToowoombaQLD4350Australia

Pit-in-pit(PIP)excavations in an aquifer–aquitard system likely undergo catastrophic failures under the hydraulic uplift,the associated undrained stability problem,however,has not been well analyzed in the *** this end,a hypothetical model of PIP braced excavation in typical soil layers of Shanghai,China is developed using the finite element limit analysis(FELA)*** FELA solutions of safety factors(FSs)against hydraulic uplift are verified with the results from the finite element analysis with strength reduction technique(SRFEA)and existing design ***,FELA is employed to identify the triggering and failure mechanisms of PIP braced excavations subjected to hydraulic uplift.A series of parametric studies considering the various geometric configurations of the PIP excavation,undrained shear strengths of aquitard,and artesian pressures are carried *** sensitivities of relevant design parameters are further assessed using a multivariate adaptive regression splines(MARS)model that is capable of accurately capturing the nonlinear relationships between a set of input variables and output variables in multi-dimensions.A MARS-based design equation used for predicting FS is finally presented using the artificial dataset from FELA for practical design uses.

关键词： Pit-in-pit excavation Hydraulic uplift Undrained stability Finite element limit analysis Multivariate adaptive regression splines

Physics-based and data-driven modeling for stability evaluation of buried structures in natural clays

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第5期15卷 1248-1262页

作者： Fengwen lai Jim shiau Suraparb Keawsawasvong Fuquan Chen Rungkhun Banyong Sorawit Seehavong Institute of Geotechnical Engineering Southeast UniversityNanjing211189China Faculty of Civil Engineering and Geosciences Delft University of Technology2628 CN Delftthe Netherlands School of Engineering University of Southern QueenslandToowoombaQLD4350Australia Department of Civil Engineering Thammasat School of EngineeringThammasat UniversityPathumthani12120Thailand College of Civil Engineering Fuzhou UniversityFuzhou350116China

This study presents a hybrid framework to predict stability solutions of buried structures under active trapdoor conditions in natural clays with anisotropy and heterogeneity by combining physics-based and data-driven ***-element limit analysis(FELA)with a newly developed anisotropic undrained shear(AUS)failure criterion is used to identify the underlying active failure mechanisms as well as to develop a numerical(physics-based)database of stability numbers for both planar and circular *** considerations are given for natural clays to three linearly increasing shear strengths in compression,extension,and direct simple shear in the AUS material *** obtained numerical solutions are compared and validated with published solutions in the literature.A multivariate adaptive regression splines(MARS)algorithm is further utilized to learn the numerical solutions to act as fast FELA data-driven surrogates for stability *** current MARS-based modeling provides both relative importance index and accurate design equations that can be used with confidence by practitioners.

关键词： Buried structures Natural clays Active trapdoor Undrained stability Multivariate adaptive regression splines (MARS) Finite element limit analysis(FELA)

Rectangular tunnel heading stability in three dimensions and its predictive machine learning models

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第11期16卷 4683-4696页

作者： Jim shiau Suraparb Keawsawasvong Van Qui lai Thanachon Promwichai Viroon Kamchoom Rungkhun Banyong School of Engineering University of Southern QueenslandQLDToowoomba4350Australia Department of Civil Engineering Thammasat School of EngineeringThammasat UniversityKlong LuangPathumthani12120Thailand Faculty of Civil Engineering Ho Chi Minh City University of Technology(HCMUT)Ho Chi Minh CityViet Nam Vietnam National University Ho Chi Minh City(VNU-HCM) Ho Chi Minh CityViet Nam Excellent Centre for Green and Sustainable Infrastructure Department of Civil EngineeringSchool of EngineeringKing Mongkut's Institute of Technology Ladkrabang(KMITL)BangkokThailand

Tunnel heading stability in two dimensions(2D)has been extensively investigated by numerous scholars in the past *** significant limitation of 2D analysis is the absence of actual tunnel geometry modeling with a considerable degree of ***,it is possible to study the stability of tunnels in three dimensions(3D)with a rectangular shape using finite element limit analysis(FELA)and a nonlinear programming *** paper employs 3D FELA to generate rigorous solutions for stability numbers,failure mechanisms,and safety factors for rectangular-shaped *** further explore the usefulness of the produced results,multivariate adaptive regression spline(MARS)is used for machine learning of big dataset and development of design equations for practical design *** study should be of great benefit to tunnel design practices using the developed equations provided in the paper.

关键词： Wide rectangular tunnel Finite element limit analysis(FELA) Multivariate adaptive regression spline(MARS) Three dimensions(3D) Stability analysis

Underground storage tank blowout analysis:Stability prediction using an artificial neural network

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Journal of Safety Science and Resilience 2023年第4期4卷 366-379页

作者： Nhat Tan Duong Van Qui lai Jim shiau Rungkhun Banyong Suraparb Keawsawasvong Faculty of Civil Engineering Ho Chi Minh City University of Technology(HCMUT)VNU-HCMHo Chi Minh CityVietnam School of Engineering University of Southern QueenslandToowoomba 4350QLDAustralia Research Unit in Sciences and Innovative Technologies for Civil Engineering Infrastructures Department of Civil EngineeringThammasat School of EngineeringThammasat UniversityPathumthani 12120Thailand

Most geotechnical stability research is linked to“active”failures,in which soil instability occurs due to soil self-weight and external surcharge *** contrast,research on passive failure is not common,as it is predominately caused by external loads that act against the soil *** earlier active trapdoor stability investigation using the Terzaghi’s three stability factor approach was shown to be a feasible method for evaluating cohesive-frictional soil ***,this technical note aims to expand“active”trapdoor research to assess drained circular trapdoor passive stability(blowout condition)in cohesive-frictional soil under axisymmetric *** numerical finite element limit analysis(FELA)simulations,soil cohesion,surcharge,and soil unit weight effects are considered using three stability factors(Fc,Fs,and Fγ),which are all associated with the cover-depth ratio and soil internal friction *** upper-bound(UB)and lower-bound(LB)results are presented in design charts and tables,and the large dataset is further studied using an artificial neural network(ANN)as a predictive model to produce accurate design *** proposed passive trapdoor problem under axisymmetric conditions is significant when considering soil blowout stability owing to faulty underground storage tanks or pipelines with high internal pressures.

关键词： Blowout Passive stability Trapdoor Stability factors Limit analysis

Accountable attribute-based authentication with fine-grained access control and its application to crowdsourcing

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Frontiers of Computer Science 2023年第1期17卷 205-218页

作者： Peng LI Junzuo lai Yongdong wu College of Information Science and Technology Jinan UniversityGuangzhou 510632China

We introduce a new notion called accountable attribute-based authentication with fine-grained access control (AccABA), which achieves (i) fine-grained access control that prevents ineligible users from authenticating;(ii) anonymity such that no one can recognize the identity of a user;(iii) public accountability, i.e., as long as a user authenticates two different messages, the corresponding authentications will be easily identified and linked, and anyone can reveal the user’s identity without any help from a trusted third party. Then, we formalize the security requirements in terms of unforgeability, anonymity, linkability and traceability, and give a generic construction to fulfill these requirements. Based on AccABA, we further present the first attribute-based, fair, anonymous and publicly traceable crowdsourcing scheme on blockchain, which is designed to filter qualified workers to participate in tasks, and ensures the fairness of the competition between workers, and finally balances the tension between anonymity and accountability.

关键词： fine-grained access control anonymous authentication accountability fairness crowdsourcing blockchain

Ultra-precision machining of cerium-lanthanum alloy with atmosphere control in an auxiliary device

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Nanotechnology and Precision Engineering 2022年第3期5卷 30-35页

作者： Chenyu Zhao Shengjie wu Min lai State Key Laboratory of Precision Measuring Technology and Instruments Laboratory of Micro/Nano Manufacturing TechnologyTianjin UniversityTianjin 300072China

Cerium–lanthanum alloys are the main component of nickel–metal hydride batteries,and they are thus an important material in the greenenergy ***,these alloys have very strong chemical activity,and their surfaces are easily oxidized,leading to great difficulties in their *** improve the corrosion resistance of cerium–lanthanum alloys,it is necessary to obtain a nanoscale surface with low ***,these alloys can easily succumb to spontaneous combustion during ***,to inhibit the occurrence of fire,machining of this alloy in ambient air needs to be conducted at very low cutting speeds while spraying the workpiece with a large amount of cutting ***,this is inefficient,and only a very limited range of parameters can be optimized at low cutting speeds;this restricts the optimization of other cutting *** achieve ultraprecision machining of cerium–lanthanum alloys,in this work,an auxiliary machining device was developed,and its effectiveness was *** results show that the developed device can improve the cutting speed and obtain a machined surface with low *** device can also improve the machining efficiency and completely prevent the occurrence of spontaneous *** was found that the formation of a build-up of swarf on the cutting tool is eliminated with high-speed cutting,and the surface roughness(Sa)can reach 5.64 nm within the selected ***,the oxidation processes of the cerium–lanthanum alloy and its swarf were studied,and the process of the generation of oxidative products in the swarf was *** results revealed that most of the intermediate oxidative products in the swarf were Ce^(3+),there were major oxygen vacancies in the swarf,and the final oxidative product was Ce^(4+).

关键词： Cerium–lanthanum alloy Ultraprecision machining Surface roughness Atmosphere control

A novel unsupervised approach for multilevel image clustering from unordered image collection

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Frontiers of Computer Science 2013年第1期7卷 69-82页

作者： lai KANG Lingda wu Yee-Hong YANG College of Information System and Management National University of Defense Technology Changsha 410073 China The Key Lab the Academy of Equipment Command & Technology Beijing 101400 China Department of Computing Science University of Alberta Edmonton Alberta T6G 2E8 Canada

A novel unsupervised approach to automatically constructing multilevel image clusters from unordered im- ages is proposed in this paper. The whole input image col- lection is represented as an imaging sample space （ISS） con- sisting of globally indexed image features extracted by a new efficient multi^view image feature matching method. By mak- ing an analogy between image capturing and observation of ISS, each image is represented as a binary sequence, in which each bit indicates the visibility of a corresponding feature. Based on information theory-inspired image popularity and dissimilarity measures, we show that the image content and distance can be quantitatively described, guided by which an input image collection is organized into multilevel clusters automatically. The effectiveness and the efficiency of the pro- posed approach are demonstrated using three real image col- lections and promising results were obtained from both qual- itative and quantitative evaluation.

关键词： multilevel image clustering imaging sample space (ISS) unordered image collection

Recent development in biogeotechnology and its engineering applications

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Frontiers of Structural and Civil Engineering 2021年第5期15卷 1073-1096页

作者： Hanjiang lai Shifan wu Mingjuan CUI Jian CHU Zijin School of Geology and Mining Fuzhou UniversityFuzhou 350108China School of Civil and Environmental Engineering Nanyang Technological UniversitySingapore 639798Singapore College of Civil Engineering Fuzhou UniversityFuzhou 350108China

Microbial geotechnology or biogeotechnology is a new branch of geotechnical *** involves the use of microbiology for traditional geotechnical *** new innovative soil improvement methods have been developed in recent years based on this approach.A proper understanding of the various approaches and the performances of different methods can help researchers and engineers to develop the most appropriate geotechnical *** present,most of the methods can be categorized into three major types,biocementation,bioclogging,and biogas *** and differences of different approaches and their potential applications are *** affecting the different processes are also *** of up-scaled model tests and pilot trials are presented to show the emerging *** challenges and problems of biogeotechnology are also discussed.

关键词： biogeotechnology biocementation bioclogging biogas strength enhancement liquefaction mitigation seepage control