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roadbed Subsidence Prediction and Its Security Evaluation

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岩石力学与工程学报 2002年第9期21卷 1368-1371页

作者： Li Yongshu 1,Han Liping 2 (1 School of Civil Eng.,Southwest Jiaotong University,Chengdu 610031 China) (2 School of Computer and Comm. Eng.,Southwest Jiaotong University,Chengdu 610031 China) School of Civil Eng. Southwest Jiaotong University Chengdu 610031 School of Computer and Comm. Eng. Southwest Jiaotong Uiversity Chengdu 610031

A roadbed subsidence pattern for predicting the security of roadbed in ground subsidence area with complicated structure strata and any shape of excavations is proposed in this paper. The methods for computing the values of the movements and deformations of the roadbed characteristic points are investigated. The calculating formulae for predicting the roadbed subsidence,inclined deformation,curvature deformation,horizontal displacement and horizontal deformation are provided. The methods for evaluating roadbed security and predicting disastrous accidents of roadbed in ground subsidence area are also discussed. Finally,a practical example is given for applying the method to evaluate roadbed security.

关键词： roadbed subsidence prediction

Permafrost Characteristics of the Qinghai-Tibet Plateau and Methods of roadbed Construction of Railway

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Acta Geologica Sinica(English Edition) 2008年第5期82卷 949-958页

作者： NIU Fujun XU Jian LIN Zhanju WU Qingbai CHENG Guodong State Key Laboratory of Frozen Soil Engineering Cold andArid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Cold Regions Road Engineering Laboratory the First Highway Design and Research Institute Xi＇an 710068 China

Permafrost along the Qinghai-Tibet railway is featured by abundant ground ice and high ground temperature. Under the influence of climate warming and engineering activities, the permafrost is under degradation process. The main difficulty in railway roadbed construction is how to prevent thawing settlement caused by degradation of permafrost. Therefore the proactively cooling methods based on controlling solar radiation, heat conductivity and heat convection were adopted instead of the traditional passive methods, which is simply increasing thermal resistance. The cooling methods used in the Qinghai-Tibet railway construction include sunshine-shielding roadbeds, crushed rock based roadbeds, roadbeds with rock revetments, duct-ventilated roadbeds, thermosyphon installed roadbeds and land bridges. The field monitored data show that the cooling methods are effective in protecting the underlying permafrost, the permafrost table was uplifted under the embankments and therefore the roadbed stability was guaranteed.

关键词： permafrost roadbed cooling method Qinghai-Tibet railway

roadbed Subsidence Mechanisms under the Driven of Penetration-Soak Coupling

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Journal of Geoscience and Environment Protection 2017年第2期5卷 97-106页

作者： Hongkai Chen Dan Liang Institute of Geotechnical Engineering Chongqing Jiaotong University Chongqing China

roadbed subsidence is one of the main types of highway flood damage, the periodic fluctuation of the river water level and the softening of the subgrade soils by the river water immersion for a long time are the main inducement factors of the subgrade subsidence. Based on the theory of absorbing water infiltration in unsaturated soil, calculation formula of dynamic stability coefficient of subgrade is established by using the Swedish arc method. Example analysis shows that, soil roadbed suffers the water permeability-soak, road-bed’s stability reduce with the time, and leads to roadbed subsidence. Research results for improving roadbed subsidence water logging mechanism understanding level have a positive meaning.

关键词： Road Engineering Subsidence Mechanism Penetration-Soaking Coupling Soil roadbed

Stress distribution in roadbeds of slab tracks with longitudinal discontinuities

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Railway Engineering Science 2023年第1期31卷 61-74页

作者： Qingzhi Ye Qiang Luo Guishuai Feng Tengfei Wang Hongwei Xie School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China MOE Key Laboratory of High-Speed Railway Engineering Southwest Jiaotong UniversityChengdu 610031China

Stress concentration occurs in the foundations of railway tracks where discontinuous components are *** exacerbated stress under the expansion joints in slab tracks may trigger foundation failures such as mud *** the higher stress due to the discontinuities of track structures has been discussed in past studies,few focused on the stress response of roadbeds in slab tracks and quantitatively characterized the stress *** this paper,we performed a dynamic finite element analysis of a track-formation system,incorporating expansion joints as primary longitudinal *** configurations of CRTS Ⅲ slab tracks and the contact conditions between concrete layers were *** results show that longitudinal influencing length of induced stress on roadbed under wheel load relates to the contact conditions between concrete layers,increasing nonlinearly at a larger coefficient of *** a measured coefficient of friction of 0.7,the calculated longitudinal influencing length(9.0 m) matches with field *** longitudinal influencing length is not affected with the increasing *** stress concentration arises with expansion joints,the worstcase scenario emerges when double-axle loads are exerted immediately above the expansion joints between concrete bases.A stress concentration factor Cvon the roadbed is proposed;it increases with the increasing velocity,changing from 1.33 to 1.52 at velocities between 5 and 400 km/*** stress distribution on roadbeds transforms from a trapezoid pattern at continuous sections to a triangle pattern at points with longitudinal *** explicit expression is finally proposed for the stress pattern on roadbed under expansion *** structural discontinuities induce stress raiser,the extent of concentration is mitigated with increasing depth at different velocity levels.

关键词： Ballastless track Expansion joint Dynamic stress roadbed Stress distribution

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多年冻土区铁路路基病害整治(英文)

冰川冻土 2004年第S1期26卷 237-240页

作者：李英武 Yitulihe Railway Office Yakeshi Inner Mongolia022168 China

The paper analysesthe treatment measurementsof railway roadbed main diseases in permafrost regions. Taking lessonsfrom the diseases finallythe mature experiences of treatments are offered.

关键词： thaw settlement of the roadbed cutting side slop sliding water outlet of icing

保护多年冻土路基中存在的问题和对策(英文)

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冰川冻土 2004年第S1期26卷 8-11页

作者： V.G.Kondratjev TransEGEM 71-31 Bolshaya Academicheskaya Street Moscow 125183 Russia

Ways of strengthening railway embankment basis on ice-rich permafrost are characterized by regulating cooling and warming factors for preservation of the basis in constantly frozen condition (with the help of snow removal, painting, sun-precipitation shed, cross-section cooling pipes, the film cover, and the longitudinal cooling device) or removing icy masses preventively from the basis and filling the cavities simultaneously with not subsiding soils (with use of jet geotechnology). Skilled-experimental development are shined on the basis of new ways of strengthening embankment basis on ice-rich frozen soils.

关键词： permafrost preservation roadbed techniques ice-rich frozen soils

A constitutive model of frozen soil with damage and numerical simulation for the coupled problem

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Science China(Physics,Mechanics & Astronomy) 2010年第4期53卷 699-711页

作者： ZHU ZhiWu, NING JianGuo& MA Wei 1 School of Mechanics and Engineering, Southwest Jiaotong University, Chengdu 610031, China 2 State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China 3 Key Laboratory of Frozen Soil Engineering, CAREERI, CAS, Lanzhou 730000, China School of Mechanics and Engineering Southwest Jiaotong University Chengdu China State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing China Key Laboratory of Frozen Soil Engineering CAREERI CAS Lanzhou China

Based on the microcosmic mechanics of composite materials, an elastic constitutive model for frozen soil with damage is presented. For frozen sandy soil with a range of ice contents and under a range of temperature conditions, quantitative results determined by this constitutive model agree with practically measured stress-strain curves. After numerically simulating the coupled water, temperature and stress fields of channel frozen and frozen roadbed using a self-developed finite-element routine, more accurate and practical calculation results for the temperature field coupled with stress, displacement and strain fields are obtained; the results match predictions and tests undertaken by earlier researchers. Our results support the reliability of our routine for calculating interdependent physical quantities of frozen soil and for describing the relationships between them. Our program can offer necessary constraints for engineering design and construction in permafrost regions.

关键词： frozen soil microcosmic mechanics roadbed coupling stress field

Technological risk regulation of the subgrade base stability in permafrost areas

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Research in Cold and Arid Regions 2017年第3期9卷 321-324页

作者： S.Ya.Lutskiy T.V.Shepitko Alexey Y.Burukin Federal State-Funded Educational Institution of Higher Vocational Education 'Moscow State University of Railway Engineering' MGUPS (MIIT) Public Joint Stock Company 'MOSTOTREST' (PJSC 'MOSTOTREST')

Maintenance and risk estimation of a weak roadbed condition during the construction period are ***-management procedure for unstable,weak soils is proposed through adjusting the technological loads and real-time monitoring of their *** efficiency of implementing maximum allowable vibroloads and the drainage system for strengthening weak soils is shown in the example of the Northern Latitudinal Railway area.

关键词： roadbed technology risk stability

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应用“天然冷”维护寒区环境(英文)

冰川冻土 2004年第S1期26卷 231-236页

作者：崔广心 Institute of Geotechnical Engineering School of Architecture and Civil Engineering China University of Mining and Technology Xuzhou Jiangsu 221008 China

The changes of frozen ground caused by the rising temperature will destroy the heat balance of frozen ground and then damage the roadbeds and foundations in cold area. It is a new idea to collect and store the “natural cold” as a resource and apply it to keep the frozen ground frozen permanently and regulate the summer temperature in cities. This paper introduces the principles and systems used in collecting, storing and transmitting the natural cold , analyses the techniques which keep the frozen ground unchanged and protect the roadbed. The paper also studies the systems and techniques by which the natural cold is used for temperature regulation in cities. And the theories involved in this subject and the prospect of industrializing those techniques are presented as well by the author.

关键词： natural cold maintaining of frozen ground roadbed in cold area