Pub Date : 2003-04-01DOI: 10.1680/GENG.2003.156.2.63
A. Phear, D. Patterson, C. Warren
Between 1999 and 2001, the Channel Tunnel Rail Link (CTRL) and the A2/M2 widening scheme between Cobham and Junction 4 of the existing M2 motorway were both under construction in central Kent. The activity was particularly intense immediately to the east of the River Medway, where the earthworks for the two projects were immediately adjacent. Nearly 300 000 m3 of surplus chalk was exported from the CTRL works to the A2/M2 widening project in a fill transfer agreement that represented the successful culmination of about three years of negotiations between the two project teams and the local planning authorities. It was a good example of waste minimisation, sustainable design and construction, and cooperative working, and involved the resolution of several planning, technical and construction management issues. The ways in which these were successfully overcome are addressed in this paper.
{"title":"Sustainable chalk fill transfer from Channel Tunnel Rail Link","authors":"A. Phear, D. Patterson, C. Warren","doi":"10.1680/GENG.2003.156.2.63","DOIUrl":"https://doi.org/10.1680/GENG.2003.156.2.63","url":null,"abstract":"Between 1999 and 2001, the Channel Tunnel Rail Link (CTRL) and the A2/M2 widening scheme between Cobham and Junction 4 of the existing M2 motorway were both under construction in central Kent. The activity was particularly intense immediately to the east of the River Medway, where the earthworks for the two projects were immediately adjacent. Nearly 300 000 m3 of surplus chalk was exported from the CTRL works to the A2/M2 widening project in a fill transfer agreement that represented the successful culmination of about three years of negotiations between the two project teams and the local planning authorities. It was a good example of waste minimisation, sustainable design and construction, and cooperative working, and involved the resolution of several planning, technical and construction management issues. The ways in which these were successfully overcome are addressed in this paper.","PeriodicalId":45150,"journal":{"name":"Geotechnical Engineering","volume":"156 1","pages":"63-73"},"PeriodicalIF":0.3,"publicationDate":"2003-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1680/GENG.2003.156.2.63","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67401642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-01-01DOI: 10.1680/GENG.156.1.47.37290
D. J. Richards, R. J. Chandler, A. Lock
It is now recognised that modifying design procedures during the active construction phase of a project in response to the measured performance of key structural elements or ground movements can yield significant productivity and cost benefits. Site monitoring schemes implemented to record these measurements often generate a large volume of data, however the processing and dissemination of which are often complicated by incompatible systems or formatting conflicts between users. This paper describes the development and use of a data format protocol for the electronic transfer of processed site data, and of a web-based data visualisation system to test the robustness of the data transfer protocol.
{"title":"Electronic data transfer systems for field monitoring","authors":"D. J. Richards, R. J. Chandler, A. Lock","doi":"10.1680/GENG.156.1.47.37290","DOIUrl":"https://doi.org/10.1680/GENG.156.1.47.37290","url":null,"abstract":"It is now recognised that modifying design procedures during the active construction phase of a project in response to the measured performance of key structural elements or ground movements can yield significant productivity and cost benefits. Site monitoring schemes implemented to record these measurements often generate a large volume of data, however the processing and dissemination of which are often complicated by incompatible systems or formatting conflicts between users. This paper describes the development and use of a data format protocol for the electronic transfer of processed site data, and of a web-based data visualisation system to test the robustness of the data transfer protocol.","PeriodicalId":45150,"journal":{"name":"Geotechnical Engineering","volume":"156 1","pages":"47-55"},"PeriodicalIF":0.3,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67401036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-01-01DOI: 10.1680/GENG.2003.156.2.83
N. Dixon, R. Hill, J. Kavanagh
This paper introduces the concept of using active waveguides as part of an acoustic emission monitoring system for assessing the stability of soil slopes. In soil, acoustic emissions are generated by inter-particle friction, and hence the detection of acoustic emission is an indication of straining. The components of a field monitoring system are introduced, and the factors controlling design and performance of waveguides are discussed. It is proposed that active waveguides (i.e. those that generate acoustic emission when deformed by the host soil) can be used as an efficient method of obtaining signals from depth within a deforming soil body. The results of laboratory tests conducted to validate the active waveguide model are presented. The role played by the soil surrounding the steel tube waveguide is highlighted. Results from two full-scale field trials that involved monitoring unstable slopes provide evidence for the relationship between detected acoustic emission and slope deformation rate. It is shown that active waveguides in conjunction with relevant signal processing methods can be used to provide an early indication of slope instability.
{"title":"Acoustic emission monitoring of slope instability: development of an active waveguide system","authors":"N. Dixon, R. Hill, J. Kavanagh","doi":"10.1680/GENG.2003.156.2.83","DOIUrl":"https://doi.org/10.1680/GENG.2003.156.2.83","url":null,"abstract":"This paper introduces the concept of using active waveguides as part of an acoustic emission monitoring system for assessing the stability of soil slopes. In soil, acoustic emissions are generated by inter-particle friction, and hence the detection of acoustic emission is an indication of straining. The components of a field monitoring system are introduced, and the factors controlling design and performance of waveguides are discussed. It is proposed that active waveguides (i.e. those that generate acoustic emission when deformed by the host soil) can be used as an efficient method of obtaining signals from depth within a deforming soil body. The results of laboratory tests conducted to validate the active waveguide model are presented. The role played by the soil surrounding the steel tube waveguide is highlighted. Results from two full-scale field trials that involved monitoring unstable slopes provide evidence for the relationship between detected acoustic emission and slope deformation rate. It is shown that active waveguides in conjunction with relevant signal processing methods can be used to provide an early indication of slope instability.","PeriodicalId":45150,"journal":{"name":"Geotechnical Engineering","volume":"156 1","pages":"83-95"},"PeriodicalIF":0.3,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1680/GENG.2003.156.2.83","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67401890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-01-01DOI: 10.1680/GENG.2003.156.1.35
S. Lo
Challenges associated with the application of partial factors to non-linear ground–structure interaction were studied for some case history examples. For some nonlinear ground–structure interaction systems, the selection of geotechnical strength parameters for calculating the movement at service condition can be important but problematic. In the calculation of action effects for structural strength design, the application of partial factors needs to simulate the trigger or path to various modes of instability, both geotechnical and structural. To avoid inconsistency, the partial factor for the self-weight of soil that is part of the interaction system needs to be set at unity. For some complex soil–structure interaction systems, the design action effects on a structural element depend on the potential failure mode examined.
{"title":"Partial factors and non-linear ground–structure interaction","authors":"S. Lo","doi":"10.1680/GENG.2003.156.1.35","DOIUrl":"https://doi.org/10.1680/GENG.2003.156.1.35","url":null,"abstract":"Challenges associated with the application of partial factors to non-linear ground–structure interaction were studied for some case history examples. For some nonlinear ground–structure interaction systems, the selection of geotechnical strength parameters for calculating the movement at service condition can be important but problematic. In the calculation of action effects for structural strength design, the application of partial factors needs to simulate the trigger or path to various modes of instability, both geotechnical and structural. To avoid inconsistency, the partial factor for the self-weight of soil that is part of the interaction system needs to be set at unity. For some complex soil–structure interaction systems, the design action effects on a structural element depend on the potential failure mode examined.","PeriodicalId":45150,"journal":{"name":"Geotechnical Engineering","volume":"156 1","pages":"35-46"},"PeriodicalIF":0.3,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1680/GENG.2003.156.1.35","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67401581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-01-01DOI: 10.1680/GENG.156.1.7.37289
C. Ng, C. Kong
In this briefing, the authors highlight some recent developments and research in slope and deep foundation engineering and in the university education system in Hong Kong.
在本简报中,作者将重点介绍香港斜坡及深基础工程及大学教育系统的最新发展和研究。
{"title":"Geotechnical engineering practice and research in Hong Kong","authors":"C. Ng, C. Kong","doi":"10.1680/GENG.156.1.7.37289","DOIUrl":"https://doi.org/10.1680/GENG.156.1.7.37289","url":null,"abstract":"In this briefing, the authors highlight some recent developments and research in slope and deep foundation engineering and in the university education system in Hong Kong.","PeriodicalId":45150,"journal":{"name":"Geotechnical Engineering","volume":"156 1","pages":"7-11"},"PeriodicalIF":0.3,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67401339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-01-01DOI: 10.1680/GENG.156.1.27.37288
J. Renaud, M. Anderson, P. L. Wilkinson, D. Lloyd, D. Wood
Limit equilibrium methods are widely used for slope design applications, dynamically coupled hydrological-slope stability models and geomorphological investigations of long-term stability. Typically, computer codes generate a single minimum factor of safety and associated slip surface. Although this is attractive in that a single statement of stability is generated, such an approach ignores the many other slip surfaces that have been analysed, some of which may be capable of providing important additional information on the stability of the slope. In this paper the authors show that it is necessary to retain and visualise all slip surface information to determine the full extent of potential slope instability.
{"title":"The importance of visualisation of results from slope stability analysis","authors":"J. Renaud, M. Anderson, P. L. Wilkinson, D. Lloyd, D. Wood","doi":"10.1680/GENG.156.1.27.37288","DOIUrl":"https://doi.org/10.1680/GENG.156.1.27.37288","url":null,"abstract":"Limit equilibrium methods are widely used for slope design applications, dynamically coupled hydrological-slope stability models and geomorphological investigations of long-term stability. Typically, computer codes generate a single minimum factor of safety and associated slip surface. Although this is attractive in that a single statement of stability is generated, such an approach ignores the many other slip surfaces that have been analysed, some of which may be capable of providing important additional information on the stability of the slope. In this paper the authors show that it is necessary to retain and visualise all slip surface information to determine the full extent of potential slope instability.","PeriodicalId":45150,"journal":{"name":"Geotechnical Engineering","volume":"156 1","pages":"27-33"},"PeriodicalIF":0.3,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67401024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-01DOI: 10.1680/GENG.2002.155.4.221
M. Preene, T. Roberts
Excavations in the Lambeth Group often encounter groundwater problems. This is related to the variable nature of the Lambeth Group soils and the presence of permeable water-bearing layers of sand, silt and gravel, where groundwater inflows can lead to instability. The permeability of the water-bearing layers can vary within a wide range. The pore water pressure and associated piezometric head in each layer can be difficult to predict, as the piezometric profile may diverge from the hydrostatic, under the influence of underdrainage from the Chalk Group and Thanet Sand Formation, which forms the lower aquifer beneath the Lambeth Group. Stability of excavations can be improved by using groundwater control techniques to reduce pore water pressures in permeable layers. Suitable methods, including active and passive pressure relief and underdrainage are discussed, and case histories presented.
{"title":"Groundwater control for construction in the Lambeth Group","authors":"M. Preene, T. Roberts","doi":"10.1680/GENG.2002.155.4.221","DOIUrl":"https://doi.org/10.1680/GENG.2002.155.4.221","url":null,"abstract":"Excavations in the Lambeth Group often encounter groundwater problems. This is related to the variable nature of the Lambeth Group soils and the presence of permeable water-bearing layers of sand, silt and gravel, where groundwater inflows can lead to instability. The permeability of the water-bearing layers can vary within a wide range. The pore water pressure and associated piezometric head in each layer can be difficult to predict, as the piezometric profile may diverge from the hydrostatic, under the influence of underdrainage from the Chalk Group and Thanet Sand Formation, which forms the lower aquifer beneath the Lambeth Group. Stability of excavations can be improved by using groundwater control techniques to reduce pore water pressures in permeable layers. Suitable methods, including active and passive pressure relief and underdrainage are discussed, and case histories presented.","PeriodicalId":45150,"journal":{"name":"Geotechnical Engineering","volume":"155 1","pages":"221-227"},"PeriodicalIF":0.3,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1680/GENG.2002.155.4.221","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67401952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-01DOI: 10.1680/GENG.2002.155.4.243
B. Indraratna, Wadud Salim
The degradation of coarse aggregates under shear stresses and its influence on the shear strength is studied, considering the energy consumption by particle breakage during shearing. An analytical model is developed relating the deviator stress ratio, dilatancy, friction angle and particle breakage under triaxial loading. Large-scale triaxial testing of latite basalt has been conducted, and the extent of particle breakage during shearing has been quantified. The breakage of particles under monotonic triaxial loading has been considered within the scope of this paper, and the modelling of particle breakage of aggregates under cyclic loading will be presented in a follow-up paper. The results show that the breakage of particles continues to increase beyond the peak deviator stress. The energy consumption by particle breakage is non-linearly related to the particle breakage index. The model also evaluates the effect of particle breakage on the friction angle of ballast. This study sheds further light on the basic angle of friction, which is independent of the breakage of particles during shearing.
{"title":"Modelling of particle breakage of coarse aggregates incorporating strength and dilatancy","authors":"B. Indraratna, Wadud Salim","doi":"10.1680/GENG.2002.155.4.243","DOIUrl":"https://doi.org/10.1680/GENG.2002.155.4.243","url":null,"abstract":"The degradation of coarse aggregates under shear stresses and its influence on the shear strength is studied, considering the energy consumption by particle breakage during shearing. An analytical model is developed relating the deviator stress ratio, dilatancy, friction angle and particle breakage under triaxial loading. Large-scale triaxial testing of latite basalt has been conducted, and the extent of particle breakage during shearing has been quantified. The breakage of particles under monotonic triaxial loading has been considered within the scope of this paper, and the modelling of particle breakage of aggregates under cyclic loading will be presented in a follow-up paper. The results show that the breakage of particles continues to increase beyond the peak deviator stress. The energy consumption by particle breakage is non-linearly related to the particle breakage index. The model also evaluates the effect of particle breakage on the friction angle of ballast. This study sheds further light on the basic angle of friction, which is independent of the breakage of particles during shearing.","PeriodicalId":45150,"journal":{"name":"Geotechnical Engineering","volume":"155 1","pages":"243-252"},"PeriodicalIF":0.3,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1680/GENG.2002.155.4.243","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67402004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-01DOI: 10.1680/GENG.2002.155.4.229
M. Long
An extensive monitoring system was installed to provide data on the behaviour of some retained masonry facades and on ground movements, resulting from basement excavation, during the redevelopment of a prestigious site in Dublin. Observations made by electrolevel beam sensors have implications for future facade retention system design. They revealed a thermally induced daily cyclic movement of the retained facades, which was partially irrecoverable. This resulted in permanent total deformations of up to 100 mm. An extended archaeological dig exacerbated the situation. The masonry was subjected to angular distortions of up to 1 in 125—values that are close to the tolerable limit. These movements ceased only when the facades were tied into the new structure. The retaining wall and temporary works support system for the new basement proved extremely stiff and watertight. Lateral wall movements were at most 1 mm and were significantly less than those predicted before the works. Back-analysis of the performanc...
{"title":"Observations of ground and structure movements during site redevelopment in Dublin","authors":"M. Long","doi":"10.1680/GENG.2002.155.4.229","DOIUrl":"https://doi.org/10.1680/GENG.2002.155.4.229","url":null,"abstract":"An extensive monitoring system was installed to provide data on the behaviour of some retained masonry facades and on ground movements, resulting from basement excavation, during the redevelopment of a prestigious site in Dublin. Observations made by electrolevel beam sensors have implications for future facade retention system design. They revealed a thermally induced daily cyclic movement of the retained facades, which was partially irrecoverable. This resulted in permanent total deformations of up to 100 mm. An extended archaeological dig exacerbated the situation. The masonry was subjected to angular distortions of up to 1 in 125—values that are close to the tolerable limit. These movements ceased only when the facades were tied into the new structure. The retaining wall and temporary works support system for the new basement proved extremely stiff and watertight. Lateral wall movements were at most 1 mm and were significantly less than those predicted before the works. Back-analysis of the performanc...","PeriodicalId":45150,"journal":{"name":"Geotechnical Engineering","volume":"155 1","pages":"229-242"},"PeriodicalIF":0.3,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1680/GENG.2002.155.4.229","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67401992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-01DOI: 10.1680/GENG.2002.155.4.253
T. Navaneethan, V. Sivakumar
Liquid limit (LL) and plastic limit (PL) are frequently used as indicators of the behaviour of fine-grained materials. These parameters are a prerequisite in every geotechnical investigation. Careful and consistent material preparation is a key component in the laboratory procedures adopted to determine the LL and PL. In preparing samples for such tests, various techniques are used in practice, and this paper examines the influence of these techniques on the actual magnitude of LL and PL measured. The index properties of a glaciolacustrine deposit, locally known as Belfast Upper Boulder Clay, which was laid down in glacial Lake Belfast, are examined. The index properties were determined on samples of the material prepared in different ways, including drying the material at two different temperatures (40°C and 110°C), crushing the dried material from coarse granular to fine granular form by adopting varying degrees of crushing effort, and mixing the dry material with both deionised water and tap water. The...
{"title":"Influence of preparation techniques on the index properties of clay","authors":"T. Navaneethan, V. Sivakumar","doi":"10.1680/GENG.2002.155.4.253","DOIUrl":"https://doi.org/10.1680/GENG.2002.155.4.253","url":null,"abstract":"Liquid limit (LL) and plastic limit (PL) are frequently used as indicators of the behaviour of fine-grained materials. These parameters are a prerequisite in every geotechnical investigation. Careful and consistent material preparation is a key component in the laboratory procedures adopted to determine the LL and PL. In preparing samples for such tests, various techniques are used in practice, and this paper examines the influence of these techniques on the actual magnitude of LL and PL measured. The index properties of a glaciolacustrine deposit, locally known as Belfast Upper Boulder Clay, which was laid down in glacial Lake Belfast, are examined. The index properties were determined on samples of the material prepared in different ways, including drying the material at two different temperatures (40°C and 110°C), crushing the dried material from coarse granular to fine granular form by adopting varying degrees of crushing effort, and mixing the dry material with both deionised water and tap water. The...","PeriodicalId":45150,"journal":{"name":"Geotechnical Engineering","volume":"155 1","pages":"253-258"},"PeriodicalIF":0.3,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1680/GENG.2002.155.4.253","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67401564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}