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Observational design method for earth structures constructed on soft ground
176A
SURFACE STRUCTURES:GEOLOGICAL FACTORS
of soils and as a variant carry out the calculations according to existing building codes. (Journal summary) 954205 Strengthening of soils during construction under chalk karst conditions V. N. Zhivoderov, Soil Mechanics & Foundation Engineering, 31(3), 1994, pp 108-110.
The experience of the State Joint-Stock Company for Stabilization of Bases and Structures (Gidrospetsstroi) in eliminating a technogenic chalk karst under complex hydrogeological conditions is reported. The causes of formation of the karst at a depth of 30-40 m and methods of eliminating piping and karstification by injecting cement grouts into the chalk by a special technology are examined. (Journal summary) 954206 Application of the observational method to hydraulic fill reclamation projects V. Choa, Geotechnique, 44(4), 1994, pp 735-745.
This paper describes the reclamation works at Changi Airport, Singapore, and the associated soil improvement works. Further reclamation work being carried out for future expansion of the airport is also described. Over 2000 ha is being reclaimed using about 200 x 106 m 3 of sand. The observational method has been applied to control the execution of the projects. Soil instrumentation has been used to control staged construction of the hydraulic fill, the coastal protection works and soil improvement of the vertical drains. Monitoring systems and site procedures to enact contingency plans are discussed. A trial using dredged clay as a reclamation material is described and the Tianjin Port East Pier project in China is used to illustrate the observational method for the construction of a retaining structure founded on soil improved by deep cement mixing. The paper also discusses the vacuum preloading method used in combination with vertical drains to improve the hydraulically placed silty clay reclamation in Tianjin. (Author)
SURFACE STRUCTURES General 954207 Surface mining A. R. Dunn & P. J. Hoddinott, in: Annual review of mining, 1994, ed T. Brewis, (Mining Journal Ltd.), 1994, pp 19-29.
This report gives an overview of worldwide surface mining operations during 1993. It emphasises the importance of regulations and adverse public opinion that severely restrict mining activity and gives examples of rehabilitation schemes. Coverage includes developments in and examples of highwall mining, drilling, fragmentation, crushing and breaking, continuous extraction and information technology. Developments and projection of future trends in machinery are covered. These include specific reference to hydraulic excavators, front-end loaders, rope excavators, dump trucks and continuous transport systems. (S.E.Long) 954208
BOSS '94. Proceedings of the seventh international conference on the behaviour of offshore structures, Massachusetts Institute of Technology, July 1994 ed C. Chryssostomidis & others, (Pergamon), ISBN (hardback) 0 08 041916 X (3 volume set), price £175.00, 1994, 1754 pp, indexes.
This three volume set contains papers presented at BOSS '94. Volume 1, entitled 'Geotechnics' contains 22 papers on the following subjects: piles and anchors for TLPs, skirt piles and caissons; site investigation; new methods of analysis; calcareous soils and shallow foundations; and soil properties. Volume 2, entitled 'Hydrodynamics and cable dynamics' contains 60 papers on the following subjects: wave drift damping; response of moored structures; second order forces and viscous dampling; cable and riser mechanics; second order forces; large scale flows; response of floating structures; wave kinematics and loads; ringing response and second order forces; viscous flows and forces; seakeeping and wave loads; simulation of marine systems; development and testing of floating systems; and loads and motions in waves. Volume 3. entitled 'Structures' contains 32 papers on the following topics: reliability analysis; inspection scheduling; design and analysis of offshore structures and pipelines; structural analysis of offshore tubulars; damage due to accidental loads and corrosion; structural consideration in jack-ups and jacket platforms; dynamic response of gravity based structures; and re-assessment and requalification of platforms. (S.E.Brown)
Geological factors of importance in surface structures 954209 Banking on firm foundations ANON, Ground Engineering, 27(10), 1994, pp 22-23.
Frankfurt already boasts some of Europe's most impressive skyscrapers - and at 300m the Commerzbank headquarters in the centre of the city will become Europe's tallest structure. Loads totalling 2000 000t will be carried by just 111 base and shaft grouted bored piles concentrated under these towers. Wind loading may put piles into tension at times. With such high pile capacities, pile depths need to be greater than previously attempted in Frankfurt. Ground conditions are clays with occasional limestone bands, which below about 25m becomes predominantly limestone with clay sand and gravel horizons under a high water pressure. Down to 25m, the most significant limestone band is a 2-3m layer at around 12m depth, which for many of Frankfurt's high rise buildings has proved a suitable founding strata. Target pile depths for the new tower are around 45m. However the limestone is fractured and its condition variable so the design relies heavily on the base and bottom shaft grouting. With high groundwater pressure there is also a risk of rupturing in the bore - particularly at the top of sand and gravel horizons - so piles have to be fully cased during construction and filled with water to balance groundwater pressures. (Author) 954210 Construction of the games arenas for the 1994 Winter Olympics in Norway T. Valstad, Survey Review, 33(255), 1995, pp 31-40.
Some most unusual structures dominated the 1994 Winter Olympics in Lillehammer, Norway. These include an ice hockey stadium carved out of solid rock, a multipurpose Olympic Hall in the shape of an upturned Viking ship, a remarkable bobsleigh- and luge track built into a mountainside with extreme tolerances and a ski jump with an Amphitheatre at the bottom. This paper presents the engineering survey techniques involved in the construction of these Olympic Games Arenas. (Author) 954211 Observational design method for earth structures constructed on soft ground E. Wakita & M. Matsuo, Geotechnique, 44(4), 1994, pp 747755.
SURFACE STRUCTURES:FOUNDATIONS This paper deals with the observational method for earth structures on soft ground. First, the failure prediction method for earth structures is described briefly. Next, the observational design method for the settlement of earth structures is proposed, and examples of its application are shown. (Authors)
Base courses and pavements 954212 Effect of orientation of approach slabs on pavement deformation H. K. W. Wong & J. C. Small, Journal of Transportation Engineering - ASCE, 120(4), 1994, pp 590-602. Differential settlements often occur between bridge abutments and the approach embankments either because the soil underlying the embankment consolidates or because the pavement and embankment materials are compressible and the bridge deck is essentially rigid. This causes a bump to form at the approach abutment, and many bridges are provided with approach slabs that span across any difference in level caused by differential settlement. Repeated traffic loadings can, however, produce a new bump at the end of the slab. To overcome this problem, approach slabs can be constructed at an angle to the horizontal, sloping down beneath the pavement. The varying thickness of base course above the slab produces a graded deformation in the pavement and results in a smoother riding surface. Model pavements and approach slabs have been tested in a laboratory-scale test track. (Authors)
954213 Incorporating elasto-plasticity in granular layer pavement design H. Wolff & A. T. Visser, Proceedings - ICE: Transport, 105(4), 1994, pp 259-272. In this paper, the development of a design method for limiting rutting in granular layers developed from data obtained through full-scale HVS testing and using the principle of S-N curves, is described. HVS data indicated that the model generally used to describe the relation between permanent strain development and number of load repetitions does not give reliable estimates of the permanent deformation at large numbers of load repetitions. The design method described here recognizes the elasto-plastic behaviour of granular materials and uses an improved model to describe the relation between permanent deformation development and number of load repetitions. (from Authors)
954214 Effect of material properties on compactability and bearing capacity C. J. Semmelink & A. T. Visser, Journal o f Transportation Engineering - ASCE, 120(4), 1994, pp 570-589. This paper gives a brief literature survey on the effect of the individual properties on the compactability of untreated road-building materials. The properties covered are the influence of the moisture content, grading (i.e., particle-size distribution), particle shape and texture, the Atterberg limits and linear shrinkage, crushing strength and durability of the material, bearing capacity of the underlying layers, and the factor influencing the bearing capacity of the material. This is foUowed by an outline of the test program and laboratory procedures. The results are then discussed, showing that compactability and bearing capacity can be quantified in terms of the indicator test values and two new properties that quantify the effects of shape and texture. Using the basic model, the influence of a lack of fines, high relative densities (i.e., high specific gravities), and the plasticity of the fines on compactability are discussed. Proposals concerning the
177A
quantification of the shape and texture of these materials are made. (Authors)
954215 The structural wear of road pavements: an assessment of the fourth power law on the AI(M) motorway in County Durham A. H. Rhodes & A. M. Suara, Proceedings - ICE." Transport, 105(4), 1994, pp 273-281. This paper records the results of an audit which has examined the structural performance of a heavily trafficked public road in Durham County. A detailed history of the construction, maintenance and classified traffic flows for the road was available, together with typical axle loads. The study estimated actual exponent values for sections of public road assuming that a power law relationship existed between structural wear and wheel load. The study showed that the actual power exponent values varied between 0.02 to 7.16 and, for exponent values that were significantly different to 4, an initial pavement design life of 20 years would no longer minimize whole fife cost. (Authors)
954216 The way forward C. Loveday, Mine & Quarry, 23(12), 1994, pp 28-30. This paper considers how we might move from the current recipe based specifications for asphalt base materials to a form of specification based on measurement of mechanical properties. It plots a way forward from the results of the BACMI/RBA/HA research and involving recent developments in the UK and European Specifications. (Author) 954217 Antiquierte Normen behindern Einsatz von RecyclingBaustoffen im Strassenbau (Antiquated standards are impeding the use of recycled building materials in road building) R. Hirt, Mensuration, Photogrammetrie, Genie Rural, 10/94, 1994, pp 450-452. The literature and testing of recycled materials show that these are at least equivalent to conventional sand and gravel mixtures. Their bearing capacity is up to 40% greater than that of high-grade round gravel. But the current product standards, largely based on the gravel standards, unsatisfactorily describe the bearing capacity properties, which are therefore mainly ignored in road design. (R.Hardbottle)
Foundations 954218 Large deformation analysis of plates on unilateral elastic foundation A. A. Khathlan, Journal of Engineering Mechanics - ASCE, 120(8), 1994, pp 1820-1827. In this technical note, the effect of large deformation on the contact of an axisymmetric circular plate that rests unilaterally on an elastic foundation is investigated. Von Karman's equations for large deformation of a thin plate are modified to include the effect of the unilateral elastic foundation. The coupled equations in terms of the plate vertical displacement and the stress function are discretized using the finitedifference method, and then solved using an incrementaliterative algorithm. Results for a circular plate with a central point load are reported for different cases. The largedeformation analysis shows that as the load increases, the contact area tends to expand until full contact is reached. The effects of the foundation modulus and the level of loading on the size of the contact zone and the plate displacement are also investigated. (Author)
SURFACE STRUCTURES:GEOLOGICAL FACTORS
of soils and as a variant carry out the calculations according to existing building codes. (Journal summary) 954205 Strengthening of soils during construction under chalk karst conditions V. N. Zhivoderov, Soil Mechanics & Foundation Engineering, 31(3), 1994, pp 108-110.
The experience of the State Joint-Stock Company for Stabilization of Bases and Structures (Gidrospetsstroi) in eliminating a technogenic chalk karst under complex hydrogeological conditions is reported. The causes of formation of the karst at a depth of 30-40 m and methods of eliminating piping and karstification by injecting cement grouts into the chalk by a special technology are examined. (Journal summary) 954206 Application of the observational method to hydraulic fill reclamation projects V. Choa, Geotechnique, 44(4), 1994, pp 735-745.
This paper describes the reclamation works at Changi Airport, Singapore, and the associated soil improvement works. Further reclamation work being carried out for future expansion of the airport is also described. Over 2000 ha is being reclaimed using about 200 x 106 m 3 of sand. The observational method has been applied to control the execution of the projects. Soil instrumentation has been used to control staged construction of the hydraulic fill, the coastal protection works and soil improvement of the vertical drains. Monitoring systems and site procedures to enact contingency plans are discussed. A trial using dredged clay as a reclamation material is described and the Tianjin Port East Pier project in China is used to illustrate the observational method for the construction of a retaining structure founded on soil improved by deep cement mixing. The paper also discusses the vacuum preloading method used in combination with vertical drains to improve the hydraulically placed silty clay reclamation in Tianjin. (Author)
SURFACE STRUCTURES General 954207 Surface mining A. R. Dunn & P. J. Hoddinott, in: Annual review of mining, 1994, ed T. Brewis, (Mining Journal Ltd.), 1994, pp 19-29.
This report gives an overview of worldwide surface mining operations during 1993. It emphasises the importance of regulations and adverse public opinion that severely restrict mining activity and gives examples of rehabilitation schemes. Coverage includes developments in and examples of highwall mining, drilling, fragmentation, crushing and breaking, continuous extraction and information technology. Developments and projection of future trends in machinery are covered. These include specific reference to hydraulic excavators, front-end loaders, rope excavators, dump trucks and continuous transport systems. (S.E.Long) 954208
BOSS '94. Proceedings of the seventh international conference on the behaviour of offshore structures, Massachusetts Institute of Technology, July 1994 ed C. Chryssostomidis & others, (Pergamon), ISBN (hardback) 0 08 041916 X (3 volume set), price £175.00, 1994, 1754 pp, indexes.
This three volume set contains papers presented at BOSS '94. Volume 1, entitled 'Geotechnics' contains 22 papers on the following subjects: piles and anchors for TLPs, skirt piles and caissons; site investigation; new methods of analysis; calcareous soils and shallow foundations; and soil properties. Volume 2, entitled 'Hydrodynamics and cable dynamics' contains 60 papers on the following subjects: wave drift damping; response of moored structures; second order forces and viscous dampling; cable and riser mechanics; second order forces; large scale flows; response of floating structures; wave kinematics and loads; ringing response and second order forces; viscous flows and forces; seakeeping and wave loads; simulation of marine systems; development and testing of floating systems; and loads and motions in waves. Volume 3. entitled 'Structures' contains 32 papers on the following topics: reliability analysis; inspection scheduling; design and analysis of offshore structures and pipelines; structural analysis of offshore tubulars; damage due to accidental loads and corrosion; structural consideration in jack-ups and jacket platforms; dynamic response of gravity based structures; and re-assessment and requalification of platforms. (S.E.Brown)
Geological factors of importance in surface structures 954209 Banking on firm foundations ANON, Ground Engineering, 27(10), 1994, pp 22-23.
Frankfurt already boasts some of Europe's most impressive skyscrapers - and at 300m the Commerzbank headquarters in the centre of the city will become Europe's tallest structure. Loads totalling 2000 000t will be carried by just 111 base and shaft grouted bored piles concentrated under these towers. Wind loading may put piles into tension at times. With such high pile capacities, pile depths need to be greater than previously attempted in Frankfurt. Ground conditions are clays with occasional limestone bands, which below about 25m becomes predominantly limestone with clay sand and gravel horizons under a high water pressure. Down to 25m, the most significant limestone band is a 2-3m layer at around 12m depth, which for many of Frankfurt's high rise buildings has proved a suitable founding strata. Target pile depths for the new tower are around 45m. However the limestone is fractured and its condition variable so the design relies heavily on the base and bottom shaft grouting. With high groundwater pressure there is also a risk of rupturing in the bore - particularly at the top of sand and gravel horizons - so piles have to be fully cased during construction and filled with water to balance groundwater pressures. (Author) 954210 Construction of the games arenas for the 1994 Winter Olympics in Norway T. Valstad, Survey Review, 33(255), 1995, pp 31-40.
Some most unusual structures dominated the 1994 Winter Olympics in Lillehammer, Norway. These include an ice hockey stadium carved out of solid rock, a multipurpose Olympic Hall in the shape of an upturned Viking ship, a remarkable bobsleigh- and luge track built into a mountainside with extreme tolerances and a ski jump with an Amphitheatre at the bottom. This paper presents the engineering survey techniques involved in the construction of these Olympic Games Arenas. (Author) 954211 Observational design method for earth structures constructed on soft ground E. Wakita & M. Matsuo, Geotechnique, 44(4), 1994, pp 747755.
SURFACE STRUCTURES:FOUNDATIONS This paper deals with the observational method for earth structures on soft ground. First, the failure prediction method for earth structures is described briefly. Next, the observational design method for the settlement of earth structures is proposed, and examples of its application are shown. (Authors)
Base courses and pavements 954212 Effect of orientation of approach slabs on pavement deformation H. K. W. Wong & J. C. Small, Journal of Transportation Engineering - ASCE, 120(4), 1994, pp 590-602. Differential settlements often occur between bridge abutments and the approach embankments either because the soil underlying the embankment consolidates or because the pavement and embankment materials are compressible and the bridge deck is essentially rigid. This causes a bump to form at the approach abutment, and many bridges are provided with approach slabs that span across any difference in level caused by differential settlement. Repeated traffic loadings can, however, produce a new bump at the end of the slab. To overcome this problem, approach slabs can be constructed at an angle to the horizontal, sloping down beneath the pavement. The varying thickness of base course above the slab produces a graded deformation in the pavement and results in a smoother riding surface. Model pavements and approach slabs have been tested in a laboratory-scale test track. (Authors)
954213 Incorporating elasto-plasticity in granular layer pavement design H. Wolff & A. T. Visser, Proceedings - ICE: Transport, 105(4), 1994, pp 259-272. In this paper, the development of a design method for limiting rutting in granular layers developed from data obtained through full-scale HVS testing and using the principle of S-N curves, is described. HVS data indicated that the model generally used to describe the relation between permanent strain development and number of load repetitions does not give reliable estimates of the permanent deformation at large numbers of load repetitions. The design method described here recognizes the elasto-plastic behaviour of granular materials and uses an improved model to describe the relation between permanent deformation development and number of load repetitions. (from Authors)
954214 Effect of material properties on compactability and bearing capacity C. J. Semmelink & A. T. Visser, Journal o f Transportation Engineering - ASCE, 120(4), 1994, pp 570-589. This paper gives a brief literature survey on the effect of the individual properties on the compactability of untreated road-building materials. The properties covered are the influence of the moisture content, grading (i.e., particle-size distribution), particle shape and texture, the Atterberg limits and linear shrinkage, crushing strength and durability of the material, bearing capacity of the underlying layers, and the factor influencing the bearing capacity of the material. This is foUowed by an outline of the test program and laboratory procedures. The results are then discussed, showing that compactability and bearing capacity can be quantified in terms of the indicator test values and two new properties that quantify the effects of shape and texture. Using the basic model, the influence of a lack of fines, high relative densities (i.e., high specific gravities), and the plasticity of the fines on compactability are discussed. Proposals concerning the
177A
quantification of the shape and texture of these materials are made. (Authors)
954215 The structural wear of road pavements: an assessment of the fourth power law on the AI(M) motorway in County Durham A. H. Rhodes & A. M. Suara, Proceedings - ICE." Transport, 105(4), 1994, pp 273-281. This paper records the results of an audit which has examined the structural performance of a heavily trafficked public road in Durham County. A detailed history of the construction, maintenance and classified traffic flows for the road was available, together with typical axle loads. The study estimated actual exponent values for sections of public road assuming that a power law relationship existed between structural wear and wheel load. The study showed that the actual power exponent values varied between 0.02 to 7.16 and, for exponent values that were significantly different to 4, an initial pavement design life of 20 years would no longer minimize whole fife cost. (Authors)
954216 The way forward C. Loveday, Mine & Quarry, 23(12), 1994, pp 28-30. This paper considers how we might move from the current recipe based specifications for asphalt base materials to a form of specification based on measurement of mechanical properties. It plots a way forward from the results of the BACMI/RBA/HA research and involving recent developments in the UK and European Specifications. (Author) 954217 Antiquierte Normen behindern Einsatz von RecyclingBaustoffen im Strassenbau (Antiquated standards are impeding the use of recycled building materials in road building) R. Hirt, Mensuration, Photogrammetrie, Genie Rural, 10/94, 1994, pp 450-452. The literature and testing of recycled materials show that these are at least equivalent to conventional sand and gravel mixtures. Their bearing capacity is up to 40% greater than that of high-grade round gravel. But the current product standards, largely based on the gravel standards, unsatisfactorily describe the bearing capacity properties, which are therefore mainly ignored in road design. (R.Hardbottle)
Foundations 954218 Large deformation analysis of plates on unilateral elastic foundation A. A. Khathlan, Journal of Engineering Mechanics - ASCE, 120(8), 1994, pp 1820-1827. In this technical note, the effect of large deformation on the contact of an axisymmetric circular plate that rests unilaterally on an elastic foundation is investigated. Von Karman's equations for large deformation of a thin plate are modified to include the effect of the unilateral elastic foundation. The coupled equations in terms of the plate vertical displacement and the stress function are discretized using the finitedifference method, and then solved using an incrementaliterative algorithm. Results for a circular plate with a central point load are reported for different cases. The largedeformation analysis shows that as the load increases, the contact area tends to expand until full contact is reached. The effects of the foundation modulus and the level of loading on the size of the contact zone and the plate displacement are also investigated. (Author)