Objective: Family‐to‐Family Education Program (FFEP) is a 12‐week course for family members of a... more Objective: Family‐to‐Family Education Program (FFEP) is a 12‐week course for family members of adults with serious mental illness (SMI). This study evaluates the effectiveness of FFEP for several family member outcomes.Method: The FFEP enrollees on a ≥3‐month waiting list were eligible; 95 consenting family members agreed to four interviews (waitlist, pre‐FFEP, post‐FFEP, and 6 months post‐FFEP) regarding subjective and objective burden, empowerment, and depression. Mixed effects ANOVA models tested hypotheses of decreased burden and increased empowerment after FFEP.Results: The FFEP was associated with reduced subjective burden (P < 0.01) and increased empowerment (P < 0.01) without changes in objective burden. Knowledge about SMI, understanding the mental health system, and self‐care also improved. There was no significant decay at 6‐month followup.Conclusion: This study provides evidence that FFEP is helpful to relatives of persons with SMI by reducing subjective burden...
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1984
The authors have previously proposed a revised definition of factor of safety for free and proppe... more The authors have previously proposed a revised definition of factor of safety for free and propped embedded retaining walls. This appeared to overcome some of the difficulties which can arise in certain situations with current definitions of factor of safety. However before the method could be considered for wider use it was essential to carry out a thorough calibration study using a wide range of input parameters to ensure that there were no unforeseen problems. This report gives results from such a parametric study in which the revised definition of factor of safety has been compared with three other definitions in current use. The main trend of the results are illustrated for both drained and undrained conditions in the soil and consideration given to the choice of definition and value to be assigned to the factor of safety. For all cases examined the revised definition appeared to be well conditioned and to provide logical results. (Author/TRRL)
The response of two clayey sands to undrained cyclic triaxial loading is described. Both the stre... more The response of two clayey sands to undrained cyclic triaxial loading is described. Both the stress history and the cyclic stress level have been varied. The behaviour is compared with that observed for the clayey sands tested under monotonic loading. Effective stress paths for the normally consolidated soils loaded monotonically in triaxial compression and extension are shown to form a hounding envelope which determines the pattern of behaviour under cyclic loading. A threshold strain is identified, below which cyclic straining results in stable behaviour. Above the threshold strain, pore pressures and strains accumulate under cyclic loading at a rate that increases as the effective stress state approaches the bounding envelope. On reaching the bounding envelope in triaxial compression, the clayey sands strain-soften. On reaching the bounding envelope in triaxial extension, there is liquefaction. L'article décrit la réponse de deux sables argileux au chargement triaxial cycliqu...
The work described in this report is part of a programme of research into the design and behaviou... more The work described in this report is part of a programme of research into the design and behaviour of embedded retaining walls which is being carried out by the Transport and Road Research Laboratory (TRRL) on behalf of the Department of Transport. During the design of the cut and cover tunnel at Bell Common, Epping, Essex for the M25 London orbital motorway, several geotechnical problems emerged with respect to the design of the in-situ retaining walls. This led to theoretical investigations of the stability, ground displacements and working stresses in the structure, (see IRRD 281207 and 271617). A small section of the Bell Common walls has been jointly monitored by the TRRL and the Building Research Establishment. This report describes a series of laboratory tests on samples of Claygate Beds and London Clay from Bell Common. The objective of the work was to use the most up to date laboratory techniques to measure the appropriate stiffness and strength parameters. These have since been used for further finite element analyses to obtain revised predictions of the Bell Common Tunnel and the results compared with the field observations (see IRRD 822044).
During construction of the running tunnels for the Jubilee Line Extension, London, large variatio... more During construction of the running tunnels for the Jubilee Line Extension, London, large variations in tunnelling volume loss were measured over about a 2 km distance between Waterloo, south of the Thames, and the area north of St James's Park. At the design stage, a value of volume loss of 2% was adopted, which was thought to be conservative. In practice, volume losses of greater than 3% were measured in Westminster and in St James's Park, south of the lake. North of the St James's Park lake volume losses were less than 2%, as expected. Reliable estimates of volume loss are required for the planning and approval of future tunnelling projects in London, and so a detailed investigation was undertaken to establish the reasons for the observed differences. Two primary and interlinked causes for the large volume losses are identified. First, the method of tunnelling and construction control: south of the lake up to 1·9 m of unsupported tunnel heading was often advanced ahead...
Proceedings of the 12th International Symposium on Landslides (Napoli, Italy, 12-19 June 2016), 2016
During an intense rainstorm on 22 May 2013, severe distress occurred at a reinforced earth wall i... more During an intense rainstorm on 22 May 2013, severe distress occurred at a reinforced earth wall in Hong Kong. The wall was under construction and nearing completion at the time of the incident. The distress involved the dislodgement of 78 facing panels, a total soil loss of about 1300 m 3 and a disturbed groundmass of some 5500 m 3. The distress occurred at three localised areas along the wall, with the formation of a sinkhole within the backfilled soil mass, referred to as the backyard of the wall. The incident resulted in significant soil deposition within the surface drainage system, flooding and debris overspill onto the road carriageway below, and it caused havoc to the local community. Subsequent to the incident, a detailed investigation was conducted to establish the probable causes and mechanism of the incident. This paper highlights some salient points of the investigation, the key findings and the lessons learnt from the incident.
The need for the research reported in this paper was driven by the Crossrail project in London fo... more The need for the research reported in this paper was driven by the Crossrail project in London for which new tunnels were constructed close to numerous existing operational tunnels of the London Underground (LU) network. This research component is based on experimental work conducted on half-scale grey cast iron (GCI) tunnel lining segments with chemical composition similar to the Victorian age GCI segments in the LU network. This paper discusses the deformation behaviour of the bolted segmental lining under the influence of factors such as overburden pressure, bolt preload and presence of grommets at small distortions. The measured behaviour of the segmental lining is compared against the calculated response of a continuous lining based on the assumption of elasticity. The industry practice for tunnel lining assessment is to calculate the induced bending moment in the tunnel lining using an elastic continuum model, while adopting a reduced lining stiffness to take into account the presence of the joints. Case studies have recorded that both loosening and tightening of lining bolts have been used as mitigation measures to reduce the impact of new tunnel excavations on existing GCI tunnels. The experimental work on the half-scale GCI lining has shown that a bolted segmental lining behaves as a continuous ring under the small distortions imposed when subjected to hoop forces relevant to the depth of burial of LU tunnels. In the presence of hoop force, joint opening was minimal and the magnitude of preload in the bolts had little impact on the behaviour of the lining. It is therefore concluded that disturbance of the bolts in existing tunnels is not recommended as a mitigation measure as in addition to being ineffective it is both time consuming and introduces the risk of damaging the tunnel lining flanges.
During construction of the Jubilee Line Extension (JLE), London, large variations in tunnelling v... more During construction of the Jubilee Line Extension (JLE), London, large variations in tunnelling volume loss, from 1.1 to 3.3%, were measured between Waterloo, south of the Thames, and the area north of St.James'sPark(about2km).AdetailedinvestigationwasundertakeninJames'sParktwoyearsafterconstruction to establish reasons for the differences of 1.2 to 3.3% observed north and south of the park.Three primary causes are identified: tunnelling method and control; differences in clay cover from past erosion and; divisions within the London Clay with markedly different geotechnical characteristics - in particular the permeability. A key point is the necessity to control construction operations very closely when tunnelling through clays containing water-bearing silt and sand partings.This case study highlights the importance of understanding the engineering geology, even in London with decades of tunnelling experience and well characterised ground conditions. The message is equally a...
Bulletin of Engineering Geology and the Environment, 1998
The 56-m high "leaning tower" of Pisa was constructed in three phases between 1173 and 1370 on th... more The 56-m high "leaning tower" of Pisa was constructed in three phases between 1173 and 1370 on the alluvial sediments of the River Arno, central west Italy. Although the tower deviated from the vertical at an early stage, the continuing tilt has led to concern about its safety. Having reviewed the construction of the tower and the underlying geology, the paper discusses the history of the tilting and describes the temporary remedial measures undertaken and permanent stabilization proposed. Résumé La Tour penchée de Pise, de 56 m de hauteur, a été construite en trois phases de 1173 à 1370, sur les alluvions de la rivière Arno, dans le Centre-Ouest de l'Italie. Bien que la tour ait commencé à basculer très tôt, la poursuite de l'inclinaison dans le temps a conduit à se poser des problèmes de sécurité. Après avoir examiné les méthodes de constuction de la tour et présenté les terrains de fondation, l'article rappelle l'histoire du basculement de la tour, décrit les mesures conservatoires provisoires et propose des méthodes pour sa stabilisation permanente.
Objective: Family‐to‐Family Education Program (FFEP) is a 12‐week course for family members of a... more Objective: Family‐to‐Family Education Program (FFEP) is a 12‐week course for family members of adults with serious mental illness (SMI). This study evaluates the effectiveness of FFEP for several family member outcomes.Method: The FFEP enrollees on a ≥3‐month waiting list were eligible; 95 consenting family members agreed to four interviews (waitlist, pre‐FFEP, post‐FFEP, and 6 months post‐FFEP) regarding subjective and objective burden, empowerment, and depression. Mixed effects ANOVA models tested hypotheses of decreased burden and increased empowerment after FFEP.Results: The FFEP was associated with reduced subjective burden (P < 0.01) and increased empowerment (P < 0.01) without changes in objective burden. Knowledge about SMI, understanding the mental health system, and self‐care also improved. There was no significant decay at 6‐month followup.Conclusion: This study provides evidence that FFEP is helpful to relatives of persons with SMI by reducing subjective burden...
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1984
The authors have previously proposed a revised definition of factor of safety for free and proppe... more The authors have previously proposed a revised definition of factor of safety for free and propped embedded retaining walls. This appeared to overcome some of the difficulties which can arise in certain situations with current definitions of factor of safety. However before the method could be considered for wider use it was essential to carry out a thorough calibration study using a wide range of input parameters to ensure that there were no unforeseen problems. This report gives results from such a parametric study in which the revised definition of factor of safety has been compared with three other definitions in current use. The main trend of the results are illustrated for both drained and undrained conditions in the soil and consideration given to the choice of definition and value to be assigned to the factor of safety. For all cases examined the revised definition appeared to be well conditioned and to provide logical results. (Author/TRRL)
The response of two clayey sands to undrained cyclic triaxial loading is described. Both the stre... more The response of two clayey sands to undrained cyclic triaxial loading is described. Both the stress history and the cyclic stress level have been varied. The behaviour is compared with that observed for the clayey sands tested under monotonic loading. Effective stress paths for the normally consolidated soils loaded monotonically in triaxial compression and extension are shown to form a hounding envelope which determines the pattern of behaviour under cyclic loading. A threshold strain is identified, below which cyclic straining results in stable behaviour. Above the threshold strain, pore pressures and strains accumulate under cyclic loading at a rate that increases as the effective stress state approaches the bounding envelope. On reaching the bounding envelope in triaxial compression, the clayey sands strain-soften. On reaching the bounding envelope in triaxial extension, there is liquefaction. L'article décrit la réponse de deux sables argileux au chargement triaxial cycliqu...
The work described in this report is part of a programme of research into the design and behaviou... more The work described in this report is part of a programme of research into the design and behaviour of embedded retaining walls which is being carried out by the Transport and Road Research Laboratory (TRRL) on behalf of the Department of Transport. During the design of the cut and cover tunnel at Bell Common, Epping, Essex for the M25 London orbital motorway, several geotechnical problems emerged with respect to the design of the in-situ retaining walls. This led to theoretical investigations of the stability, ground displacements and working stresses in the structure, (see IRRD 281207 and 271617). A small section of the Bell Common walls has been jointly monitored by the TRRL and the Building Research Establishment. This report describes a series of laboratory tests on samples of Claygate Beds and London Clay from Bell Common. The objective of the work was to use the most up to date laboratory techniques to measure the appropriate stiffness and strength parameters. These have since been used for further finite element analyses to obtain revised predictions of the Bell Common Tunnel and the results compared with the field observations (see IRRD 822044).
During construction of the running tunnels for the Jubilee Line Extension, London, large variatio... more During construction of the running tunnels for the Jubilee Line Extension, London, large variations in tunnelling volume loss were measured over about a 2 km distance between Waterloo, south of the Thames, and the area north of St James's Park. At the design stage, a value of volume loss of 2% was adopted, which was thought to be conservative. In practice, volume losses of greater than 3% were measured in Westminster and in St James's Park, south of the lake. North of the St James's Park lake volume losses were less than 2%, as expected. Reliable estimates of volume loss are required for the planning and approval of future tunnelling projects in London, and so a detailed investigation was undertaken to establish the reasons for the observed differences. Two primary and interlinked causes for the large volume losses are identified. First, the method of tunnelling and construction control: south of the lake up to 1·9 m of unsupported tunnel heading was often advanced ahead...
Proceedings of the 12th International Symposium on Landslides (Napoli, Italy, 12-19 June 2016), 2016
During an intense rainstorm on 22 May 2013, severe distress occurred at a reinforced earth wall i... more During an intense rainstorm on 22 May 2013, severe distress occurred at a reinforced earth wall in Hong Kong. The wall was under construction and nearing completion at the time of the incident. The distress involved the dislodgement of 78 facing panels, a total soil loss of about 1300 m 3 and a disturbed groundmass of some 5500 m 3. The distress occurred at three localised areas along the wall, with the formation of a sinkhole within the backfilled soil mass, referred to as the backyard of the wall. The incident resulted in significant soil deposition within the surface drainage system, flooding and debris overspill onto the road carriageway below, and it caused havoc to the local community. Subsequent to the incident, a detailed investigation was conducted to establish the probable causes and mechanism of the incident. This paper highlights some salient points of the investigation, the key findings and the lessons learnt from the incident.
The need for the research reported in this paper was driven by the Crossrail project in London fo... more The need for the research reported in this paper was driven by the Crossrail project in London for which new tunnels were constructed close to numerous existing operational tunnels of the London Underground (LU) network. This research component is based on experimental work conducted on half-scale grey cast iron (GCI) tunnel lining segments with chemical composition similar to the Victorian age GCI segments in the LU network. This paper discusses the deformation behaviour of the bolted segmental lining under the influence of factors such as overburden pressure, bolt preload and presence of grommets at small distortions. The measured behaviour of the segmental lining is compared against the calculated response of a continuous lining based on the assumption of elasticity. The industry practice for tunnel lining assessment is to calculate the induced bending moment in the tunnel lining using an elastic continuum model, while adopting a reduced lining stiffness to take into account the presence of the joints. Case studies have recorded that both loosening and tightening of lining bolts have been used as mitigation measures to reduce the impact of new tunnel excavations on existing GCI tunnels. The experimental work on the half-scale GCI lining has shown that a bolted segmental lining behaves as a continuous ring under the small distortions imposed when subjected to hoop forces relevant to the depth of burial of LU tunnels. In the presence of hoop force, joint opening was minimal and the magnitude of preload in the bolts had little impact on the behaviour of the lining. It is therefore concluded that disturbance of the bolts in existing tunnels is not recommended as a mitigation measure as in addition to being ineffective it is both time consuming and introduces the risk of damaging the tunnel lining flanges.
During construction of the Jubilee Line Extension (JLE), London, large variations in tunnelling v... more During construction of the Jubilee Line Extension (JLE), London, large variations in tunnelling volume loss, from 1.1 to 3.3%, were measured between Waterloo, south of the Thames, and the area north of St.James'sPark(about2km).AdetailedinvestigationwasundertakeninJames'sParktwoyearsafterconstruction to establish reasons for the differences of 1.2 to 3.3% observed north and south of the park.Three primary causes are identified: tunnelling method and control; differences in clay cover from past erosion and; divisions within the London Clay with markedly different geotechnical characteristics - in particular the permeability. A key point is the necessity to control construction operations very closely when tunnelling through clays containing water-bearing silt and sand partings.This case study highlights the importance of understanding the engineering geology, even in London with decades of tunnelling experience and well characterised ground conditions. The message is equally a...
Bulletin of Engineering Geology and the Environment, 1998
The 56-m high "leaning tower" of Pisa was constructed in three phases between 1173 and 1370 on th... more The 56-m high "leaning tower" of Pisa was constructed in three phases between 1173 and 1370 on the alluvial sediments of the River Arno, central west Italy. Although the tower deviated from the vertical at an early stage, the continuing tilt has led to concern about its safety. Having reviewed the construction of the tower and the underlying geology, the paper discusses the history of the tilting and describes the temporary remedial measures undertaken and permanent stabilization proposed. Résumé La Tour penchée de Pise, de 56 m de hauteur, a été construite en trois phases de 1173 à 1370, sur les alluvions de la rivière Arno, dans le Centre-Ouest de l'Italie. Bien que la tour ait commencé à basculer très tôt, la poursuite de l'inclinaison dans le temps a conduit à se poser des problèmes de sécurité. Après avoir examiné les méthodes de constuction de la tour et présenté les terrains de fondation, l'article rappelle l'histoire du basculement de la tour, décrit les mesures conservatoires provisoires et propose des méthodes pour sa stabilisation permanente.
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Papers by J. Burland