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Topological identification of block assemblages for jointed rock masses
SITE INVESTIGATIONS :REMOTE SENSING structure. Some numerical examples illustrating the proposed analyses are also presented. -Authors
Identification and classification 945104 A geological a p p r o a c h toward developing a m u d r o c k - d u r a h i l i t y classification system J. C. Dick, A. Shakoor & N. Wells, Canadian GeotechnicalJournal, 31(1), 1994, pp 17-27. Relationships between durability and lithologic characteristics of 61 mudrock samples from North America were investigated with the objective of developing a mudrockdurability classification based on lithologic characteristics. The durability of claystones correlates best with the amount of expandable clay minerals and that of mudstones with the frequency of microfractures. The degree of consolidation, as expressed by absorption, influences the durability of both siltstones and shales. The durability of argillites is related to their crystalline texture. Lithologic characteristics can be quantitatively related to a durability classification that recognizes three classes of durability: low (ld 2 < 50%), medium (Id 2 = 50%-85%), and high (Id 2 > 85%). -from Authors 945105 Topological identification of block assemblages for jointed rock masses L. Jing & O. Stephansson, International Journal of Rock Mechanics & Mining Sciences, 31(2), 1994, pp 163-172. An algorithm to identify block assemblages for jointed rock masses is developed by using basic topological concepts of orientations of edges and blocks, digraphs and regularized sets of edges. It produces vertex loops defining all individual blocks which may be convex, concave, multiply connected or of infinitely large areas. The method can be used to provide a basic data structure of block systems to establish geometrical models for DEM or other numerical methods prior to the final discretization of intact materials. -from Authors 945106 A review: genesis and classification of tropical residual soils for engineers P . G . Fookes, in: Geotechnics in the African environment. Vol. 2, ed G.E. Blight & others, (Balkema), 1994, pp 423-442. The paper describes simply the genesis of tropical residual soils and classification, based on a pedological subdivision by Duchaufour (1982), into three principal soil phases, fersiallitic, ferruginous and ferrallitic, which represent a continuous increase in tropical soft development from a Mediterranean to a hot, wet, tropical climate. 'Standard' red tropical residual soils typically belong to the fermginous and. ferrallitic phases. Modification of significance to the engineering characteristics is made where there is a seasonal dry climate. The soils then develop a hardened (lateritic) zone or crust. Dark young soils (typically the fersiallitic stage) can be further subdivided to distinguish those with sweWshrink characteristics and other properties of significance to engineering, depending on the clay mineral species formed. -from Author 945107 Procedimentos p a r a caracterizacao geotecnica de perils em solos de granitos e gnaisses, p a r a obras viarias (Procedures for geotechnical characterization of granitic and gneissic soil profiles, for t r a n s p o r t a t i o n ways works) H. Godoy, J. Shuji Nogami & A, Carvalho, Solos e Rochas, 17(1), 1994, pp 31-44. The soils composing the layers of various profiles associated with granites and gneisses are characterized for preliminary comparison purposes, aiming at the utilization in transportation ways works. A conclusion can be drawn that traditionalprocedures, whether based on index properties (w L, Iw a n a grain-size), or on geological and pedological data, generally provide information less effective than that obtained by use of the MCT methodology. -English summary
237A
945108 The Speeton Clay of North Yorkshire, England: an investigation of its geotechnical properties F. G. Bell, Engineering Geology, 36(3-4), 1994, pp 257-266. The Lower Cretaceous in North Yorkshire is represented by a marine succession termed the Speeton Clay. The principal minerals in these clays consist of quartz, mica and clay minerals, although pyrite, glauconite and siderite are notable in some beds. The proportions of clay minerals change within the Speeton Clay and generally illite becomes more important in the younger horizons. The Speeton Clay is a silty clay which generally has a high plasticity. Neither theplasticity nor the moisture content were affected by depth. In terms of its undrained shear strength, most of the Speetun Clay could be regarded as a stiff clay. It was also insensitive with generally a low slake-durability index. -from Author
SITE INVESTIGATION AND FIELD OBSERVATION 945109 Without site investigation ground is a hazard G. S. Littlejohn, K. W. Cole & T. W. Mellors, Proceedings - ICE: Civil Engineering, 102(2), 1994, pp 72-78. This Paper aims to raise awareness of the importance of ground, and it highlights the consequences of inadequate site investigation in terms of escalating costs and late completions. Inadequate site investigations can result from lack of awareness, inadequate focus of finance, insufficient time or lack of geotecimical expertise. The essential elements of site investigation are reviewed and recommendations made to improve practice and obtain better value for money. A site investigation should be undertaken for every site, since without a .properly procured, supervised and interpreted site investlgatmn, the hazards in the ground cannot be known. -from Authors
Remote sensing and photographic techniques 945110
A comparison of ground penetrating r a d a r methods: multi-fold data vs. single fold data L . M . Liberty & J. R. Pelton, in: Hydrogeology, waste disposal, science and politics. Proc. 30th symposium on engineering geology and geotechnical engineering, Idaho, 1994, ed P.K. Link, (Idaho State University), 1994, pp 321-330. A comparison of the single fold method vs. the multffold m e t h o d for acquisition and processing of GPR data is presented. Data are shown from an old lumber mill site on a river flood plain which has undergone excavation and backfilling. Results show an improved image can be attained by compensating for the problems related to complex geology, a complex wavefield and cultural noise. The results also show that in re~ions with a complex near-surface, multi-fold radar sectaons are the preferred method over single fold coverage. Stee]~ly dipping horizons are placed in a correct spatial posltion and reflections are oetter imaged in the section by reducing coherent noise. Additional time and computing resources are needed for acquisition and processing of the data, but the costs are justified by an improved and more accurate radar section. -from Authors 945111 Ground penetrating r a d a r and seismic refraction investigation of fracture patterns in the basalt of Lucky Peak near Boise, Idaho M. E. Dougherty, W. K. Hudson, S. E. Kay & R. J. Vincent, in: Hydrogeology, waste disposal, science and politics. Proc. 30th symposium on engineering g e o l o g y and geotechnical engineering, Idaho, 1994, ed P.K. Link, (Idaho State University), 1994, pp 345-357. Work presented here is an attempt to use surface geophysical methods to delineate areas within a basalt flow which display different fracture characteristics and which have different electrical and seismic properties. The Basalt of Lucky Peak is an intracanyon basalt flow exposed in cliffs
Identification and classification 945104 A geological a p p r o a c h toward developing a m u d r o c k - d u r a h i l i t y classification system J. C. Dick, A. Shakoor & N. Wells, Canadian GeotechnicalJournal, 31(1), 1994, pp 17-27. Relationships between durability and lithologic characteristics of 61 mudrock samples from North America were investigated with the objective of developing a mudrockdurability classification based on lithologic characteristics. The durability of claystones correlates best with the amount of expandable clay minerals and that of mudstones with the frequency of microfractures. The degree of consolidation, as expressed by absorption, influences the durability of both siltstones and shales. The durability of argillites is related to their crystalline texture. Lithologic characteristics can be quantitatively related to a durability classification that recognizes three classes of durability: low (ld 2 < 50%), medium (Id 2 = 50%-85%), and high (Id 2 > 85%). -from Authors 945105 Topological identification of block assemblages for jointed rock masses L. Jing & O. Stephansson, International Journal of Rock Mechanics & Mining Sciences, 31(2), 1994, pp 163-172. An algorithm to identify block assemblages for jointed rock masses is developed by using basic topological concepts of orientations of edges and blocks, digraphs and regularized sets of edges. It produces vertex loops defining all individual blocks which may be convex, concave, multiply connected or of infinitely large areas. The method can be used to provide a basic data structure of block systems to establish geometrical models for DEM or other numerical methods prior to the final discretization of intact materials. -from Authors 945106 A review: genesis and classification of tropical residual soils for engineers P . G . Fookes, in: Geotechnics in the African environment. Vol. 2, ed G.E. Blight & others, (Balkema), 1994, pp 423-442. The paper describes simply the genesis of tropical residual soils and classification, based on a pedological subdivision by Duchaufour (1982), into three principal soil phases, fersiallitic, ferruginous and ferrallitic, which represent a continuous increase in tropical soft development from a Mediterranean to a hot, wet, tropical climate. 'Standard' red tropical residual soils typically belong to the fermginous and. ferrallitic phases. Modification of significance to the engineering characteristics is made where there is a seasonal dry climate. The soils then develop a hardened (lateritic) zone or crust. Dark young soils (typically the fersiallitic stage) can be further subdivided to distinguish those with sweWshrink characteristics and other properties of significance to engineering, depending on the clay mineral species formed. -from Author 945107 Procedimentos p a r a caracterizacao geotecnica de perils em solos de granitos e gnaisses, p a r a obras viarias (Procedures for geotechnical characterization of granitic and gneissic soil profiles, for t r a n s p o r t a t i o n ways works) H. Godoy, J. Shuji Nogami & A, Carvalho, Solos e Rochas, 17(1), 1994, pp 31-44. The soils composing the layers of various profiles associated with granites and gneisses are characterized for preliminary comparison purposes, aiming at the utilization in transportation ways works. A conclusion can be drawn that traditionalprocedures, whether based on index properties (w L, Iw a n a grain-size), or on geological and pedological data, generally provide information less effective than that obtained by use of the MCT methodology. -English summary
237A
945108 The Speeton Clay of North Yorkshire, England: an investigation of its geotechnical properties F. G. Bell, Engineering Geology, 36(3-4), 1994, pp 257-266. The Lower Cretaceous in North Yorkshire is represented by a marine succession termed the Speeton Clay. The principal minerals in these clays consist of quartz, mica and clay minerals, although pyrite, glauconite and siderite are notable in some beds. The proportions of clay minerals change within the Speeton Clay and generally illite becomes more important in the younger horizons. The Speeton Clay is a silty clay which generally has a high plasticity. Neither theplasticity nor the moisture content were affected by depth. In terms of its undrained shear strength, most of the Speetun Clay could be regarded as a stiff clay. It was also insensitive with generally a low slake-durability index. -from Author
SITE INVESTIGATION AND FIELD OBSERVATION 945109 Without site investigation ground is a hazard G. S. Littlejohn, K. W. Cole & T. W. Mellors, Proceedings - ICE: Civil Engineering, 102(2), 1994, pp 72-78. This Paper aims to raise awareness of the importance of ground, and it highlights the consequences of inadequate site investigation in terms of escalating costs and late completions. Inadequate site investigations can result from lack of awareness, inadequate focus of finance, insufficient time or lack of geotecimical expertise. The essential elements of site investigation are reviewed and recommendations made to improve practice and obtain better value for money. A site investigation should be undertaken for every site, since without a .properly procured, supervised and interpreted site investlgatmn, the hazards in the ground cannot be known. -from Authors
Remote sensing and photographic techniques 945110
A comparison of ground penetrating r a d a r methods: multi-fold data vs. single fold data L . M . Liberty & J. R. Pelton, in: Hydrogeology, waste disposal, science and politics. Proc. 30th symposium on engineering geology and geotechnical engineering, Idaho, 1994, ed P.K. Link, (Idaho State University), 1994, pp 321-330. A comparison of the single fold method vs. the multffold m e t h o d for acquisition and processing of GPR data is presented. Data are shown from an old lumber mill site on a river flood plain which has undergone excavation and backfilling. Results show an improved image can be attained by compensating for the problems related to complex geology, a complex wavefield and cultural noise. The results also show that in re~ions with a complex near-surface, multi-fold radar sectaons are the preferred method over single fold coverage. Stee]~ly dipping horizons are placed in a correct spatial posltion and reflections are oetter imaged in the section by reducing coherent noise. Additional time and computing resources are needed for acquisition and processing of the data, but the costs are justified by an improved and more accurate radar section. -from Authors 945111 Ground penetrating r a d a r and seismic refraction investigation of fracture patterns in the basalt of Lucky Peak near Boise, Idaho M. E. Dougherty, W. K. Hudson, S. E. Kay & R. J. Vincent, in: Hydrogeology, waste disposal, science and politics. Proc. 30th symposium on engineering g e o l o g y and geotechnical engineering, Idaho, 1994, ed P.K. Link, (Idaho State University), 1994, pp 345-357. Work presented here is an attempt to use surface geophysical methods to delineate areas within a basalt flow which display different fracture characteristics and which have different electrical and seismic properties. The Basalt of Lucky Peak is an intracanyon basalt flow exposed in cliffs