Proceedings of the Institution of Civil Engineers-Geotechnical Engineering最新文献

{"title":"Soil-structure interaction behind integral bridge abutments","authors":"Michael Wiechecki, I. Thusyanthan, P. Nowak, J. Sandberg","doi":"10.1680/jgeen.22.00115","DOIUrl":"https://doi.org/10.1680/jgeen.22.00115","url":null,"abstract":"Integral bridges are preferred on infrastructure schemes as they have lower maintenance costs than a conventional jointed bridge. A key aspect of integral bridge design is the assessment of long-term passive resistance that develops in the abutment backfill due to seasonal movements of the superstructure. This resistance is currently defined by an intermediate earth pressure coefficient termed K*, and is typically evaluated using the Limit Equilibrium (LE) approach prescribed in BSI PD-6694-1:2011+A1:2020. This paper adopts the alternate numerical design approach and investigates the development of K* behind full height abutments using Soil-Structure Interaction (SSI) modelling in PLAXIS-2D. The study demonstrates that mobilised passive resistance is primarily a function of backfill and structural stiffnesses, and that the current LE approach does not capture the backfill resistance profile correctly. The effectiveness of the SSI method was verified by comparison to the LE method. The current study provides a SSI methodology that is an efficient design approach, and which is suitable for a wide variety of integral bridge arrangements beyond the current LE method applicability.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89569558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of compaction water on strength and hydraulic properties of bentonite based liner","authors":"S. Rout, S. Singh","doi":"10.1680/jgeen.22.00173","DOIUrl":"https://doi.org/10.1680/jgeen.22.00173","url":null,"abstract":"Abundance of pond ash and its resemblance with natural sand encourages its use as a substitute to sand in sand-bentonite (SB) liner material. Compaction water content influences the geoengineering properties of cohesive soil to a great extent. Accordingly, compaction, strength, permeability and shrinkage characteristics of both pond ash-bentonite (PAB) and SB mixes are investigated at standard and modified Proctor compaction energies at various water contents to support the recommendation of PAB mixture as an alternative landfill liner. At similar compaction conditions, PAB mix exhibits higher unconfined compressive strength (UCS) and hydraulic conductivity than that of SB mix. The UCS values of the dry-side compacted mixes are higher than those of the wet-side of compacted mixes. Dry-side compacted mixes shows a reduction in hydraulic conductivity with permeation time whereas; no substantial reduction in hydraulic conductivity is noticed for wet-side compacted mixes. Furthermore, the volumetric shrinkage of both PAB and SB mixes are within the permissible value of 4%, for a wide range of water variation from dry to wet-side of optimum. The observed mechanical properties are correlated to the shape of coarse fraction particle and the corresponding microstructural arrangements of the compacted specimens.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76957998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A practical framework for characterising the non-linear stiffness of overconsolidated soils and weak rock","authors":"T. O'brien, Xinjin Ho, Ringo Tan","doi":"10.1680/jgeen.22.00210","DOIUrl":"https://doi.org/10.1680/jgeen.22.00210","url":null,"abstract":"Limit state design codes such as Eurocode 7 require good estimates of displacement to be made for serviceability checks. It is known that the stiffness of over-consolidated soils and weak rocks is highly non-linear and this needs to be taken into account for reliable displacements to be calculated. This paper outlines a relatively simple means of characterising the undrained and drained non-linear stiffness of a wide range of soils and rocks. A series of practical applications are described where the calculated stiffness non-linearity is compared with high quality field and laboratory test data, including back-analysis of full-scale structures. The non-linear stiffness function requires just four inputs: shear modulus at small-strain, shear strength, failure strain, and elastic threshold strain. Applications include: checking advanced test data and calibration of non-linear constitutive models; derivation of field stiffness, including variations with depth, non-linear stiffness curves, and assessing the potential effects of stiffness anisotropy.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82949986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discrete element method modeling of structural clay","authors":"Jiawei Xu, Junneng Ye, Jin Sun, X. Bian","doi":"10.1680/jgeen.22.00224","DOIUrl":"https://doi.org/10.1680/jgeen.22.00224","url":null,"abstract":"Structures in clay, found as an important role resulting in the weakness and failure of foundations under disturbance, are mainly caused by the cementation between particles. Existing constitutive models reflect the failure characteristics of clay from the phenomenological aspect, while the mechanism of the clay damage from a microscopic perspective is still unclear. In this study, the discrete element method, together with the bond and cohesive contact model, which were introduced for capturing the cohesion and structure of soft clay, respectively, is used to reproduce the cementation of clay, the numerical models of confined compression test, vane shear test and triaxial test were established, aiming to reveal the influence of structure of clay on its deformation and failure process. The results exhibited that the deformation and stress-strain development were in good agreement with experimental results in macroscopic. Moreover, the relationship between the structural failure and the macroscopic mechanical behavior can be established, which is helpful to better uncover the failure mechanism of structural clay. According to this developed of failure surface under the micro scale, an optimized suggestions were proposed for the conventional shear stress calculation in the vane shear test. The method in this study has the potential to simulate the mechanical behavior of structural clay and how significant implications for the improvement of the constitutive models and engineering design.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80043298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The surface bearing capacity of a strong granular layer on weaker sand","authors":"A. Lees, A. Ali","doi":"10.1680/jgeen.22.00094","DOIUrl":"https://doi.org/10.1680/jgeen.22.00094","url":null,"abstract":"Stronger granular layers are often placed as working platforms over weaker sand subgrade. The design of a working platform involves the calculation of a two-layer bearing capacity under rectangular loading. Existing design methods are either overly simplified, based on infinitely long strip loads, validated by a small number of small-scale 1g model tests or rely on numerous or empirically derived charts that are difficult to use or implement into design software. In this paper a new and highly practical design method is proposed where bearing capacity is determined simply from the shear strengths and unit weights of the two soil layers. It was derived from extensive FEA and FELA parametric studies in both plane strain and axisymmetric geometries and validated against published physical model tests, other FELA analyses and existing design methods. It can be applied to all rectangular shape ratios with dry and saturated layers.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72545895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Propagation characteristics of stress wave in layered rock mass under the impact of high-pressure gas","authors":"Haixia Wei, Chengzhi Wang, Jie Zhu, Xiaolin Yang, Huaibao Chu","doi":"10.1680/jgeen.22.00116","DOIUrl":"https://doi.org/10.1680/jgeen.22.00116","url":null,"abstract":"As a highly safe and environment-friendly blasting technology, high-pressure gas blasting has replaced traditional explosive blasting in some engineering fields. This paper focuses on the characteristics of high-pressure gas impact load and the propagation law of the stress wave in layered rock mass under high-pressure gas blasting by experimental and numerical simulation methods. Firstly, through the experimental test of hole wall pressure, a segmented exponential model of the hole wall pressure under the impact of high-pressure gas is proposed, which can accurately account for the time history characteristics of hole wall load under the impact of high-pressure gas. Next, the experimental test of stress wave propagation is carried out, and the results show that the interface of soft rock and hard rock has a significant effect on the stress wave propagation in the layered rock mass. Based on the experimental test results, a specific strain model under 10 MPa high-pressure gas impact is fitted for single-hole layered rock mass, and a polynomial exponential model form is put forward and a specific strain model under 20 MPa high-pressure gas impact is fitted for the double-hole layered rock mass, which can well characterize the attenuation law of the stress wave for single-hole and double-hole layered rock mass respectively. The propagation characteristics of stress wave in layered rock mass under the impact of high-pressure gas are preliminary analyzed. Finally, a same numerical model consistent with the experimental test of stress wave propagation is established. The numerical model adopts the RHT material model with the tested parameters, and the proposed segmented exponential models of hole wall pressure are applied to the lower, middle and upper parts of the blasthole respectively. After the feasibility of the numerical model is analyzed, the propagation characteristics of the stress wave are further studied based on a specific underground pipe gallery project by numerical simulation. This study has important theoretical guiding significance and practical value for improving the rock breaking theory and optimizing the construction scheme of high-pressure gas blasting in layered rock mass.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79634619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resilient strain and stiffness degradation of Yellow River silt under long-term cyclic loads","authors":"Yu-ke Wang, Rui Jiang, Yufeng Gao, J. Shao","doi":"10.1680/jgeen.22.00097","DOIUrl":"https://doi.org/10.1680/jgeen.22.00097","url":null,"abstract":"The use of natural River silt treated as \"waste materials\" has become the focused research in the Yellow River flooded area, especially in the highway engineering recently. It is of great significance to study the deformation and stiffness degradation of the Yellow River silt under long-term cyclic loads. In this paper, a series of undrained cyclic triaxial tests with a large number of cycles (10000 times) for Yellow River silt have been carried out by using triaxial apparatus, the effects of confining pressure and cyclic stress ratio on the resilient strain of the Yellow River silt were explored. The critical cyclic stress and critical cyclic stress ratio between the plastic shakedown state and incremental collapse state of the Yellow River silt were determined, and the modulus softening behaviour of the Yellow River silt are discussed. This study not only provided theoretical support for the long-term engineering performance of the Yellow River silt, but also provided theoretical guidance for the cyclic response of all similar types of subgrade soils.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81388671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"What is the probability of encountering unexploded bombs on a U.K. construction site?","authors":"J. Gask, J. Moran","doi":"10.1680/jgeen.21.00138","DOIUrl":"https://doi.org/10.1680/jgeen.21.00138","url":null,"abstract":"Quantitative risk data is essential for the efficient and consistent assessment of risk and allows for the effective use of cost-benefit analysis for assessing mitigating measures. The quantitative assessment of the risk posed by unexploded bombs (UXBs) on construction sites within the U.K. involves the identification of a set of contributory risk factors and modelling the interaction between them. The interaction of the risk factors has been modelled using Monte Carlo Simulation built into a new risk assessment tool (JG-MCS). Some of the output results from the tool are presented, including the limited validation that is possible against published work. The tool is used to assess the sensitivity of risk to some of the problem variables and several of the underlying assumptions are investigated. The model has also been extended to explore the influence of investigative mitigation measures. In this paper a set of fundamental questions are raised regarding the risks being assessed, how they are presented and the efficacy of some mitigation measures. For the scenario used, it was found that the overall risk of UXB encounter was low before mitigation and only slightly lower after mitigation. It was also found that the cost of implementing measures to reduce the risk posed by UXBs might be considered to be below the bracket of what is described by the HSE as ‘reasonably practicable’.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85045767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discussion: Effect of soil models on the prediction of tunnelling-induced deformations of structures","authors":"Giorgia Giardina, Nunzio Losacco, Matthew J. DeJong, Giulia M. B. Viggiani, Robert J. Mair, J. N. Shirlaw, S. J. Boone","doi":"10.1680/jgeen.22.00123","DOIUrl":"https://doi.org/10.1680/jgeen.22.00123","url":null,"abstract":"","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135803689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geotechnical Engineering: Referees 2022","authors":"","doi":"10.1680/jgeen.2023.176.1.104","DOIUrl":"https://doi.org/10.1680/jgeen.2023.176.1.104","url":null,"abstract":"","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80834076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}