- Email: [email protected]
More haste more cost
40A
EXCAVATIONS:CONSTRUCTION
analysis of rock nature and structure, stresses, strain, strength and stability and whole chapters are devoted to excavation, support and rock classification. Intended for use by consultants and students in engineering geology and waste disposal, this book will also appeal to engineers and geologists with a limited background in rock mechanics. (S.E.Long)
Stresses around openings 961325 Basic study of expert system for predicting weighting in coal face 0n Chinese) Jiang Fuxing, Song Zhenqi, Song Yang, Yang Yongjie, Zbao Weidong & Qian Minggao, Journal - China Coal Society, 20(3), 1995, pp 225-228. Based on the study of mechanism of roof weighting in coal face, an expert system for forecasting pattern, inferring strategy, monitoring method and data processing method are established. This established a bridge between 'automatic forecasting' and 'forecasting mechanism'. The expert system of weighting on the basis of this knowledge can satisfy the demand of roof weighting forecasting in longwall face.
(English summary)
Excavation failure mechanisms 961326 Pillar failure by axial splitting in brittle rocks G. E. Exadaktylos & C. E. Tsoutrelis, International Journal of Rock Mechanics & Mining Sciences, 32(6), 1995, pp 551562. An analytical approximate elastic model is presented of the pillar failure mechanism in the case of multiple underground openings in brittle rocks by parallel equidistant vertical splitting cracks forming slabs, which are assumed to buckle. The failure region is considered to be elliptical in shape with the major axis growing as failure proceeds parallel to the minimum applied principal stress. A modified solution for the potential energy loss due to the presence of an elliptical hole in an infinite elastic space was derived in order to account for multiple openings. This solution, yields the failure initiation stress and the crack spacing. Comparison of the theoretical results with field data concerning a bauxite mine using room and pillar have indicated reasonable agreement. Furthermore, the scale effect exhibited by the strength and the axial splitting crack spacing was predicted sufficiently well by the model. (from Authors) 961327 Tunnel fining removal prompts LA Metro collapse A. Oliver, New Civil Engineer (NCE), 1134, 1995, pp 3-5. Reports on the collapse during construction and remedial works on the Los Angeles Metro Tunnel, USA. Sections of the 6.7m diameter, four segment lined tunnel roof had been removed and relining was in progress to correct a alignment problem when the collapse occurred. Unexpected ground conditions in the alluvium are being blamed. It is claimed a leaking water main had saturated the silty ground above the tunnel. (J.M.McLanghlin) 961328 Epic drama A. Greeman, New Civil Engineer (NCE), 1138, 1995, pp 1619. The article reports on the progress of the construction of the new Athens metro. Problems encountered during tunnelling and station construction are discussed, including collapsing ground and the prevalence of archaeological sites. Tunnelling has been concentrated under the 8m to 10m deep archaeologically rich ground of the Neolithic, old Greek, Roman and Byzantine cities, by utilizing TBMs to drive 9.5m outside diameter running tunnels. (C.Palce)
Tunnels 961329 Soft ground not easy ground for TBM V. Perrone, M. Oatman & A. Larson, Civil Engineering ASCE, 65(2), 1995, pp 70-71. The King County Department of Metropolitan Services faced with the need to transfer wastewater from the West Seattle drainage basin to a secondary treatment plant on the other side of a ridge, opted to construct a tunnel that could also store stormwater. The 10 200 ft project, conveying up to 19 mgd, lies 30 to 385 ft below the ridge. Construction will start in the spring of 1995 with an earth pressure balance tunneling machine equipped with flood doors in the cutter head shield and access through the cutter head for removing boulders and servicing the equipment. The tunnel liner will be bolted and gasketed precast concrete segments. (from Authors) 961330 More haste more cost ANON, New Civil Engineer (NCE), 1133, 1995, pp 10-11. This article discusses why the Limehouse Link Tunnel costs so much more than the original estimates; from an initial £51 million to nearly £300 million. A report published by the National Audit Office shows that the project was rushed and that the London Docklands Development Corporation pursued a complex cut and cover tunnel option even after it became clear this was not the cheapest option. The report reveals that the LDDC to be a construction client for which speed was the primary mover and evidence of insufficient management and financial controls. (C.Paice)
Mines and quarries 961331 Underground bauxite exploitation in the western Dinurides: essential facts and comments S. Vujev, R. Marusic & K. Sakac, Rudarsko Geolosko Naftni Zbornik, 6, 1994, pp 71-94. A concise sketch of the geologic structure of the bauxite regions of the Western Dinarides is presented, including the chemical composition of the bauxites. The main portion of the paper is devoted to the description of the following bauxitic regions: Drnis, Obrovac, Mostar, Jajce, Bosanska Krupa, and Sinj. The bauxitic history of the region and its mining characteristics are described. (from Authors)
Landfills 961332 Materials for the final cover of sanitary landfills D. Kovacic, Rudarsko Gealosko Naftni Zbornik, 6, 1994, pp 11-15. The paper deals with the selection of materials for the seating layer in the final cover of sanitary landfills. The sealing layer is the most critical component of the final cover. Its role is to minimize percolation of water through the final cover. Materials used for the construction of the seating layer are either of mineral origin (compacted clay) or geosynthetic (geomembrane). They are most often used in combination creating composite liners. Recently alternative materials are also used like paper mill sludge or discarded swelling clay. (Author)
Construction methods 961333 Final pull R. Byles, New Civil Engineer (NCE), 1132, 1995, pp 20-21. Norfolk contractor Dredging & Construction is using land baaed directional drilling and pipe pulling techniques to
EXCAVATIONS:CONSTRUCTION
analysis of rock nature and structure, stresses, strain, strength and stability and whole chapters are devoted to excavation, support and rock classification. Intended for use by consultants and students in engineering geology and waste disposal, this book will also appeal to engineers and geologists with a limited background in rock mechanics. (S.E.Long)
Stresses around openings 961325 Basic study of expert system for predicting weighting in coal face 0n Chinese) Jiang Fuxing, Song Zhenqi, Song Yang, Yang Yongjie, Zbao Weidong & Qian Minggao, Journal - China Coal Society, 20(3), 1995, pp 225-228. Based on the study of mechanism of roof weighting in coal face, an expert system for forecasting pattern, inferring strategy, monitoring method and data processing method are established. This established a bridge between 'automatic forecasting' and 'forecasting mechanism'. The expert system of weighting on the basis of this knowledge can satisfy the demand of roof weighting forecasting in longwall face.
(English summary)
Excavation failure mechanisms 961326 Pillar failure by axial splitting in brittle rocks G. E. Exadaktylos & C. E. Tsoutrelis, International Journal of Rock Mechanics & Mining Sciences, 32(6), 1995, pp 551562. An analytical approximate elastic model is presented of the pillar failure mechanism in the case of multiple underground openings in brittle rocks by parallel equidistant vertical splitting cracks forming slabs, which are assumed to buckle. The failure region is considered to be elliptical in shape with the major axis growing as failure proceeds parallel to the minimum applied principal stress. A modified solution for the potential energy loss due to the presence of an elliptical hole in an infinite elastic space was derived in order to account for multiple openings. This solution, yields the failure initiation stress and the crack spacing. Comparison of the theoretical results with field data concerning a bauxite mine using room and pillar have indicated reasonable agreement. Furthermore, the scale effect exhibited by the strength and the axial splitting crack spacing was predicted sufficiently well by the model. (from Authors) 961327 Tunnel fining removal prompts LA Metro collapse A. Oliver, New Civil Engineer (NCE), 1134, 1995, pp 3-5. Reports on the collapse during construction and remedial works on the Los Angeles Metro Tunnel, USA. Sections of the 6.7m diameter, four segment lined tunnel roof had been removed and relining was in progress to correct a alignment problem when the collapse occurred. Unexpected ground conditions in the alluvium are being blamed. It is claimed a leaking water main had saturated the silty ground above the tunnel. (J.M.McLanghlin) 961328 Epic drama A. Greeman, New Civil Engineer (NCE), 1138, 1995, pp 1619. The article reports on the progress of the construction of the new Athens metro. Problems encountered during tunnelling and station construction are discussed, including collapsing ground and the prevalence of archaeological sites. Tunnelling has been concentrated under the 8m to 10m deep archaeologically rich ground of the Neolithic, old Greek, Roman and Byzantine cities, by utilizing TBMs to drive 9.5m outside diameter running tunnels. (C.Palce)
Tunnels 961329 Soft ground not easy ground for TBM V. Perrone, M. Oatman & A. Larson, Civil Engineering ASCE, 65(2), 1995, pp 70-71. The King County Department of Metropolitan Services faced with the need to transfer wastewater from the West Seattle drainage basin to a secondary treatment plant on the other side of a ridge, opted to construct a tunnel that could also store stormwater. The 10 200 ft project, conveying up to 19 mgd, lies 30 to 385 ft below the ridge. Construction will start in the spring of 1995 with an earth pressure balance tunneling machine equipped with flood doors in the cutter head shield and access through the cutter head for removing boulders and servicing the equipment. The tunnel liner will be bolted and gasketed precast concrete segments. (from Authors) 961330 More haste more cost ANON, New Civil Engineer (NCE), 1133, 1995, pp 10-11. This article discusses why the Limehouse Link Tunnel costs so much more than the original estimates; from an initial £51 million to nearly £300 million. A report published by the National Audit Office shows that the project was rushed and that the London Docklands Development Corporation pursued a complex cut and cover tunnel option even after it became clear this was not the cheapest option. The report reveals that the LDDC to be a construction client for which speed was the primary mover and evidence of insufficient management and financial controls. (C.Paice)
Mines and quarries 961331 Underground bauxite exploitation in the western Dinurides: essential facts and comments S. Vujev, R. Marusic & K. Sakac, Rudarsko Geolosko Naftni Zbornik, 6, 1994, pp 71-94. A concise sketch of the geologic structure of the bauxite regions of the Western Dinarides is presented, including the chemical composition of the bauxites. The main portion of the paper is devoted to the description of the following bauxitic regions: Drnis, Obrovac, Mostar, Jajce, Bosanska Krupa, and Sinj. The bauxitic history of the region and its mining characteristics are described. (from Authors)
Landfills 961332 Materials for the final cover of sanitary landfills D. Kovacic, Rudarsko Gealosko Naftni Zbornik, 6, 1994, pp 11-15. The paper deals with the selection of materials for the seating layer in the final cover of sanitary landfills. The sealing layer is the most critical component of the final cover. Its role is to minimize percolation of water through the final cover. Materials used for the construction of the seating layer are either of mineral origin (compacted clay) or geosynthetic (geomembrane). They are most often used in combination creating composite liners. Recently alternative materials are also used like paper mill sludge or discarded swelling clay. (Author)
Construction methods 961333 Final pull R. Byles, New Civil Engineer (NCE), 1132, 1995, pp 20-21. Norfolk contractor Dredging & Construction is using land baaed directional drilling and pipe pulling techniques to