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Influence of differential settlement on pavement structure of widened roads based on large-scale model test

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Journal of Rock Mechanics and Geotechnical Engineering 2011年第1期3卷 90-96页

作者： Xiaolin Weng1,2,Wei Wang3 1 Key Laboratory for Special Area Highway Engineering of Ministry of Education,Chang’an University,Xi’an,710064,China 2 CCCC First Highway Consultants Co.,Ltd.,Xi’an,710068,China 3 Henan Vocational and Technical College of Communications,Zhengzhou,450005,China Key Laboratory for Special Area Highway Engineering of Ministry of Education Chang’an University Xi’an 710064 China CCCC First Highway Consultants Co. Ltd Xi’an 710068 China Henan Vocational and Technical College of Communications Zhengzhou 450005China

This study introduced at first the background of numerous highway widening projects that have been developed in recent years in *** a large ground settlement simulator and a fiber Bragg grating (FBG) strain sensor network system,a large-scale model test,with a similarity ratio of 1:2,was performed to analyze the influence of differential settlement between new and old subgrades on pavement structure under loading *** result shows that excessive differential settlement can cause considerable tensile strain in the pavement structure of a widened road,for which a maximum value (S) of 6 cm is *** the repetitive load,the top layers of pavement structure are subjected to the alternate action of tensile and compressive strains,which would eventually lead to a fatigue failure of the ***,application of geogrid to the splice between the new and the old roads can reduce differential settlement to a limited *** new subgrade of a widened road is vulnerable to the influence of dynamic load transferred from the above pavement *** for the old subgrade,due to its comparatively high stiffness,it can well spread the load on the pavement statically or *** test also shows that application of geogrid can effectively prevent or defer the failure of pavement *** geogrid,the modulus of resilience of the subgrade is increased and inhomogeneous deformation can be reduced;therefore,the stress/strain distribution in pavement structure under loading condition becomes *** results obtained in this context are expected to provide a helpful reference for structural design and maintenance strategy for future highway widening projects.

关键词： widened subgrade differential settlement fiber Bragg grating (FBG) strain sensor model test

differential uplift and settlement between inner column and diaphragm wall in top-down excavation

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Journal of Central South University 2015年第9期22卷 3578-3590页

作者：王丽郑刚欧若楠 School of Civil and Safety Engineering Dalian Jiaotong University Key Laboratory of Coast Civil Structure Safety of Ministry of Education (Tianjin University) Honors School Harbin Institute of Technology

Top structure and basement will confront the risk of being damaged on account of large stress and strain fields incurred by differential uplift and settlement between inner column and diaphragm wall in top-down method. Top-down excavation of the Metro Line 10 in Shanghai was modeled with finite element analysis software ABAQUS and parameters of subsoil were obtained by inverse analysis. Based on the finite element model and parameters, changes in the following factors were made to find more effective methods to restrain differential uplift and settlement: length of diaphragm wall, thickness of jet-grouting reinforcement layer, ways of subsoil reinforcement, sequence of pit excavation, connection between slabs and diaphragm wall or column and width of pit. Several significant results are acquired. The longer the diaphragm wall is, the greater the differential uplift between column and diaphragm wall is. Rigidity of roof slab is in general not strong enough to keep diaphragm wall and column undergoing the same uplift during excavation; Uplift at head of column and differential uplift between column and diaphragm wall decrease when subsoil from-16.6 to-43 m in pit is reinforced through jet-grouting. But, as excavation proceeds to a lower level, benefit from soil reinforcement diminishes. During the process applying vertical load, the larger the depth of diaphragm wall is, the smaller the settlement is at head of column and diaphragm wall, and the greater the differential settlement is between column and diaphragm wall. When friction connection is implemented between column, diaphragm wall and floor slabs, uplifts at head of column and diaphragm wall are larger than those of the case when tie connection is implemented, and so does differential uplift between column and diaphragm wall. The maximum deflection of diaphragm wall decreases by 58% on account of soil reinforcement in pit. The maximum deflection of diaphragm wall decreases by 61.2% when friction connection is i

关键词： top-down method differential uplift differential settlement jump-layer excavation diaphragm wall with outriggers

Analysis of the influence factors of differential settlement of high embankment in mountain area

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Analysis of the influence factors of differential settlement...

Finite element prediction on the response of non-uniformly arranged pile groups considering progressive failure of pile-soil system

2011 World Congress on Engineering and Technology(CET 2011)

作者： Min Geng College of Civil Engineering Hebei University of Technology Beichen district, Tianjin, P. R. China 300401 Yuanming Dou College of Civil Engineering Hebei University of Technology Beichen district, Tianjin, P. R. China 300401

This paper reveals and analyses various influence factors which cause differential settlement of high embankment in mountain area using indoor consolidation test and field loading test. In this research, the actual stress characteristics of high embankment are simplified, stability compression value of stuffing with loads under lateral restricted conditions can be measured, e p curves and p s curves are drew, we can calculate compression modulus as computation criteria to estimate the settlement of high embankment. The results indicate that unconsolidated flow of high embankment is the main factor to cause differential settlement of high embankment in mountain area. As the soil consolidated, compressive deformation and the strength gradually increase, the bearing capacity of the foundation is enhanced to reduce differential settlement of the post-construction of high embankment.

关键词： road engineering high embankment differential settlement consolidation test

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Frontiers of Structural and Civil Engineering 2020年第4期14卷 961-982页

作者： Qian-Qing ZHANG Shan-Wei LIU Ruo-Feng FENG Jian-Gu QIAN Chun-Yu CUI Geotechnical and Structural Engineering Research Center Shandong UniversityJinan 250061China Key Laboratory of Geotechrical and Underground Engineering of the Minstry of Education Tongji UniversityShanghai 200092China

A uniform arrangement of individual piles is commonly adopted in the conventional pile group foundation,and basin-shaped settlement is often observed in *** differential settlement of pile groups will decrease the use-safety requirements of building,even cause the whole-building tilt or *** reduce differential settlement among individual piles,non-uniformly arranged pile groups can be *** paper presents a finite element analysis on the response of pile groups with different layouts of individual piles in pile *** the userdefined subroutine FRIC as the secondary development platform,a softening model of skin friction and a hyperbolic model of end resistance are introduced into the contact pair calculation of ABAQUS *** to the response analysis of a single pile,the reliability of the proposed secondary development method of ABAQUS software is verified using an iterative computer *** reinforcing effects of individual piles is then analyzed using the present finite element ***,the response of non-uniformly arranged pile groups,e.g.,individual piles with variable length and individual piles with variable diameter,is analyzed using the proposed numerical analysis *** suggestions on the layout of individual piles are proposed to reduce differential settlement and make full use of the bearing capacity of individual piles in pile groups for practical purposes.

关键词： numerical simulation non-uniformly arranged pile groups differential settlement pile-soil interaction

Floating-roof steel tanks under harmonic settlement: FE parametric study and design criterion

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第3期7卷 398-406页

作者：赵阳曹庆帅谢新宇 Department of Civil Engineering Zhejiang University Hangzhou 310027 China

Large vertical steel tanks for fluid storage are usually constructed on soft foundations, so it is not surprising that the tank wall will settle unevenly with the settlement of the foundation, thus inducing deformations and stresses in the tank. This work investigates the linear static behavior of floating-roof tanks under harmonic settlement through finite element (FE) analyses. The influences of the radius-to-thickness ratio, the height-to-radius ratio and the wind girder stiffness on the structural behavior are first analyzed. Comparisons between the circumferential stresses in the wind girder and the vertical stresses in the tank bottom are then made. The displacement and the stress along the tank height are also discussed, and the concept of tank division along its height is presented. Finally, a design approximation for the radial displacement at the tank top is developed based on FE results, and a settlement criterion based on the top radial displacement is proposed which can be used in practical design.

关键词： Steel tanks Floating-roof differential settlement Harmonic settlement Finite element analysis Design criterion

Thermal and deformational repairing effect of crushed rock revetment acting as reinforcement along Qinghai–Tibet railway in permafrost regions

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Advances in Climate Change Research 2022年第3期13卷 421-431页

作者： Yan-Dong HOU Qing-Bai WU Ming-Li ZHANG Feng-Xi ZHOU School of Civil Engineering Lanzhou University of TechnologyLanzhou 730050China State Key Laboratory of Frozen Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of ScienceLanzhou 730000China Beiluhe Observation Station of Frozen Soil Environment and Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of ScienceLanzhou 730000China

Due to the particularity and complexity of permafrost subgrade,research on its long-term maintenance and reinforcement under climate warming and engineering activities is of great *** mitigate subgrade diseases caused by thermal disturbance during the engineering construction and operation in the initial stage,the crushed-rock revetment(CRR)was additionally paved with a thickness of 1.5 m and 1.0 m on some sunny and shady shoulders of the traditional embankments along the Qinghai-Tibet railway,*** improving effects for thermal and deforming stability are evaluated based on observation data of ground temperatures and embankment deformations at two sites from 2002 to *** results show that a larger uplifting magnitude in the artificial permafrost table(APT),greater ground temperature decreasing amplitudes and reduction ranges of settling rate appear under the shady embankment shoulder in warm permafrost region,and both sides in the cold permafrost region when reinforcing with ***,in warm permafrost region,the laying of CRR on the sunny slope of subgrade may cause considerable thermal disturbance to the underlying permafrost foundation,combined with the resulting additional stress,induce the further expansion of differential ***,the thermal stability strengthening effect of the CRR is closely related to the variation of the APT thickness in the earlier stage,convection intensity inside the CRR,‘cold energy reserve’in the deeper permafrost,and amount of solar radiation received by the *** effective reinforcements should be implemented to alleviate the potential threaten beneath sunny embankment slope in warm permafrost regions.

关键词： Ice-rich permafrost Crushed-rock revetment differential settlement Thermal stability Artificial permafrost table

settlement ANALYSIS OF GRANULAR FILL ON SOFT SOIL UNDER CIRCULAR LOAD

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2001年第2期2卷 66-71页

作者：梁旭吴伟丰蔡袁强潘晓东 Geotechnical Engineering Research Institute Dept. of Civil Engineering Zhejiang University Hangzhou China Office of Construction Zhejiang University Hangzhou China

This paper presents a theoretical model and new idea for designing granular fill oil-tanks foundation. The finite difference method was used to analyze the influence of the oil-tanks radius, the modulus, and thickness of the granular fill on the maximum and differential settlement of a granular fill foundation of oil-tanks. Comparison of the modelled results with those of traditional method and observation showed that the new method could be used efficiently in practice.

关键词： circular load granular fill shear layer maximum settlement differential settlement

Influence and Control Strategy for Local settlement for High-Speed Railway Infrastructure

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Engineering 2016年第3期2卷 374-379页

作者： Gaoliang Kang Bureau of Transport & Department of Track Maintenance China Railway Corporation Beijing 100844 China

This paper discusses the main impact factors of the local settlement and differential settlement of high- speed railway lines. The analysis results show that groundwater exploitation is the direct cause of differ- ential settlement. Based on the study of ballastless track additional load and of vehicle, track, and bridge dynamic responses under different differential settlements, a control standard of differential settlement during operation is proposed preliminarily.

关键词： Local settlement differential settlement Additional load of ballastless track Vehicle and track dynamics

Explanation of the Damage to the Royal Family’s Cemetery in Historic Cairo and Examination of the Building Materials

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Open Journal of Civil Engineering 2021年第1期11卷 28-59页

作者： Ahmed Elyamani Nabil A. Abd El-Tawab Bader Mahmoud Algohary Ragab Abou El Hassan Department of Archaeological Conservation Faculty of Archaeology Cairo University Cairo Egypt Treatment and Conservation Department Faculty of Archaeology Zagazig University Zagazig Egypt Restoration and Conservation of Antiquities Department Faculty of Archaeology and Tourism Guidance Misr University for Science and Technology 6th October City Egypt

The cemetery of the royal family, who ruled Egypt from 1805 to 1952, is one of the masterpieces of the UNESCO World Heritage Site of Historic Cairo. It is a complex building from massive stone masonry walls supporting hemispherical domes and is very rich with the marble decorative elements. Unfortunately, it suffers nowadays from serious cracking due to on-going structural damage. Almost all the structural elements are cracked. Besides, the continuous rise in the groundwater table affects both its structural stability and aesthetics. A detailed inspection was carried out to identify and explain all the manifested damage by the structural elements of the cemetery. The differential settlement damage was found to be very noticeable in the form of many diagonal cracks that are active and threaten the overall stability of the cemetery. The construction history was investigated and found to have a clear effect on the noticed damage. Examination of the construction materials and deterioration products was carried out by inspecting representative samples of the stone, the marble, the mortar, the plaster and the salt. They were examined using different analysis techniques including the Polarized Microscope, the Stereo Microscope, the X-Ray Diffraction (XRD), and the Scanning Electron Microscope (SEM) provided with Energy-Dispersive X-ray spectroscopy (EDX) unit. This examination helped in identifying the type of the used stone, the mortar components, the types of salts affecting the structure, and the deterioration manifested by the marble. It seems that the cemetery needs an urgent conservation project to stop the deterioration and keep it safe for the next generations.

关键词： Historic Cairo Cemetery differential settlement Groundwater Damage XRD SEM-EDX Examination