bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment of wastewater for irrigation in Mauritius
Authors: Amblin G. J.
Published: November 2009

When complete, the St Martin Sewage Treatment Plant will serve nearly a third of Mauritius’ 1·1 million population. As well as protecting the marine environment, it will provide a valuable source of water to supplement irrigation supplies to west-coast sugar-cane plantations. This paper explains: (a) the treatment process selection which favoured conventional activated sludge over extended aeration; (b) the need for nutrient removal; and (c) the choice of ultraviolet (UV) irradiation for disinfection and problems of dyes from the substantial textile industry. It also describes the complexity of the effluent discharge control system designed to: (a) release a tertiary quality effluent to the irrigation canals blended with the present surface water supplies to avoid sodium accumulation in the soils; (b) avoid flooding the canals; and (c) provide an emergency storm flow discharge via the same common outfall pipe to the sea. Construction of the new treatment plant at St Martin began in January 2001 and is due to be completed in August 2004.
Briefing: Sustainable development: a ‘monument for eternity’?
Authors: Hawkins R. G. P. , Shaw H.
Published: November 2009

This paper discusses and illustrates the impermanence, chimerical nature, and inherent subjectivity of the term sustainable development. Doubt is cast on the criteria for its present use and the future of the term sustainable development, together with the present public unquestioning acceptance of its continuance. This paper examines a number of commonly held assumptions about sustainable development. For those who believe sustainable development can provide a framework for policy, a basis for international or temporal comparison, or a benchmark for industry against which environmental progress will be measured, this paper is intended as an encouragement to review and reconsider its application.
Briefing: Sustainability reporting: an anchor, not the answer
Authors: Olsen Leon
Published: November 2009

Although there is a considerable increase in the number of organisations producing social or sustainable development reports, the truth is that most stakeholders are simply not interested. In response, the Ashridge Centre for Business and Society has undertaken research to find out how companies can ensure successful social or sustainable development reporting. This briefing paper outlines the findings and offers insights into how leading companies ensure successful reporting
Briefing: Making London a walkable city
Authors: Tanner Graham
Published: November 2009

The level of walking in London has fallen steadily over the past 50 years but this decline has accelerated over the last decade with a 13% fall in walking trips. To try to reverse this trend, Transport for London (TfL) has published the Walking Plan for London, developed to assist all organisations involved in taking the Plan forward. The Plan supports the revitalisation of public spaces and the creation of a high-quality urban environment that enriches Londoners’ experience and appreciation of walking as a valued and enjoyable activity.
Engineering to shape a better world
Authors: Langford P.
Published: November 2009

Each year the ICE President is invited to deliver his Presidential Address to members of the Institution of Engineers of Ireland (IEI) and the IEI President is invited to deliver his address to members of the ICE. This year, IEI President Peter Langford chose sustainable development as his theme. His address demonstrated the contribution of engineers to economic and social progress and showed how influential the engineering profession has been in developing the communication networks (infrastructure and electronic), the health and the very fabric of society. He followed up this analysis by identifying the challenges which lie ahead in the twenty-first century and by describing some of the solutions engineers in Ireland have found to help deliver a more sustainable future for us all.
Coarse recycled aggregates for use in new concrete
Authors: Limbachiya M. C.
Published: November 2009

The results of a laboratory experimental programme aimed at examining the performance of Portland-cement concrete produced with natural (gravel and sand) and coarse recycled aggregates (RA) are reported in this paper. All concrete mixes were designed for equivalent 28-day compressive cube strengths of 20, 30 and 40 N/mm2. The effects of up to 100% coarse RA on fresh, engineering and durability properties have been established and its suitability for use in a range of designated applications assessed. The results for the fresh concrete showed a reduction in workability of the concrete with increase in RA proportion beyond 30% in the mix, although the slump measurements remained within the allowable margins of ±25 mm. The mixes with high proportions of RA were found to be less cohesive and exhibited slight bleeding. Studies of hardened concrete properties, comprising bulk engineering properties (compressive cube strength, flexural strength, modulus of elasticity, drying shrinkage) and durability (initial surface absorption, carbonation rates, freeze–thaw in water and abrasion resistance) showed similar performance for RA and natural aggregate concrete mixes of equivalent strength.
Reuse of tyre steel fibres as concrete reinforcement
Authors: Pilakoutas K. , Neocleous K. , Tlemat H.
Published: November 2009

To attain economically viable and environmentally friendly tyre recycling, it is necessary to develop new applications and products, which will use tyre by-products (especially the steel cord) as raw materials. The authors demonstrate that the steel fibres recovered from used tyres can be used to reinforce concrete elements. This application has a great potential, as it is estimated that more than 500000 t of high-quality steel fibres could be recovered annually from used tyres in the EU alone. This paper presents the work carried out as part of various ongoing projects on the use of steel fibres in concrete construction. The first part of the paper deals with waste management issues, the methods used to recover steel fibres from tyres, and existing applications of used tyres. The second part presents the mechanical behaviour of concrete elements reinforced with these steel fibres and discusses the relevant design and economic issues. It is concluded that the use of these steel fibres in concrete construction will benefit not only the construction industry, but also the producers and recyclers of used tyres.
Re-use of zinc smelting furnace slag in concrete
Authors: Morrison C. , Richardson D.
Published: November 2009

Slag from the imperial smelting furnace (ISF) method of zinc production is an industry by-product that has been investigated for its potential use as an aggregate in concrete. In the UK alone, there is currently a 2·5 million t stockpile of ISF slag that could potentially be used as aggregate in the construction industry. However, the presence of the heavy metals zinc and lead in the slag raises environmental concerns about its reuse. ISF slag is physically suitable for use as an aggregate, although there are several barriers that need to be overcome before it can be used in concrete. Issues relating to the metal ions present have been addressed in other publications. However, the glassy nature of the slag initially raised concerns regarding the potential for alkali–silica reaction (ASR) to occur in concrete. A comprehensive series of accelerated ASR tests have been carried out, which indicate that the material is not susceptible to this type of deleterious reaction. In addition, site trials on a concrete roadway containing ISF slag have proved successful.
Concrete bridges in sustainable development
Authors: Martin A. J.
Published: November 2009

Concrete bridges form significant links in most infrastructure schemes, but as a constructional material concrete faces major challenges concerning its sustainability performance. The paper seeks to identify and discuss significant themes in sustainability as they affect concrete bridges and to give a briefing on the subject to bridge owners, designers, constructors, maintainers and users. After introducing the challenge of sustainability to the concrete industry, a structured means of addressing sustainability issues is presented and the role of concrete in bridge construction is described. The four major aspects of sustainable thinking (natural resources, environment, societal issues and economics) are discussed in the context of concrete bridges. Examples of how sustainable principles have been applied to practical situations involving concrete bridges are then presented and discussed. In conclusion, the need for further research to provide practical sustainability assessment tools is identified together with the importance of increased awareness and involvement of all through education and training.
Energy recovery from thermal processing of waste: a review
Authors: Yassin L. , Lettieri P. , Simons S. , Germanà A.
Published: November 2009

In the developed world, 75% of the population live in urban areas, a figure projected to rise to nearly 83% by 2030, while in the developing world, the rate of urbanisation is even faster. One of the most important environmental problems associated with urbanisation is the amount of waste that is generated at a rate that outstrips the ability of the natural environment to assimilate it and authorities to manage it. If, therefore, we are to deliver a more sustainable economy, we must do more with less by making better use of resources and putting these materials to good use. The use of municipal solid waste to produce energy or fuel is not only an important waste treatment option in itself but it also cuts down on the use of fossil fuels and hence can help meet renewable energy targets, address concerns about global warming and contribute significantly to achieving Kyoto Protocol commitments. This paper reviews the state-of-the-art technologies used in the thermal treatment processes of waste including combustion, gasification and pyrolysis. It also highlights some non-technical barriers to commercialisation of these technologies.
Briefing: Ice, snow and water – impacts of climate change on California and Himalayan Asia
Authors: Fenner Richard A
Published: November 2009

This briefing outlines the issues discussed at an international workshop held in San Diego in May 2009, which focused on the impact on water resources of declining mountain snows and glacier retreat in Himalayan Asia and western USA. The workshop concluded that, because adaptation strategies are locally conditioned, new regional climate assessments are required that link global climate models to local decision making.
Integrated policies for environmental resilience and sustainability
Authors: Hunt J.
Published: November 2009

Policies for resilience against disasters use forecasts for short and longer term environment hazards, both natural and artificial. Although the methods used are increasing in reliability, significant uncertainties remain in the underpinning science and in the data. The vulnerability of communities to environmental risk is increasing because of economic and social factors, which also need to be better understood. This paper shows why, over the long term, engineering, medical and social policies for improving resilience are most effective when they are firmly linked to those for sustainable development. Policies need to be coordinated globally to meet agreed United Nations objectives and also to ensure that environmental actions in one region can benefit and do not damage sustainable development in other areas. Analyses and simulations of emerging and other possible scenarios, using economics and complex systems modelling, can test and propose strategies for resilience and sustainability, including the merits of different types of integration. This approach provides new insights for public discussion and decision making. There are new ways that universities, research institutes, non-governmental organisations and the private sector can contribute to multi-disciplinary technical advances and to promoting public participation in the complex changes affecting communities everywhere.
Sustainable community waste collection in Karachi, Pakistan
Authors: Ahmed N.
Published: November 2009

Low-income communities residing in squatter settlements usually develop their own services through self-help efforts. Such schemes include solid waste disposal, with the aim of placing household and other kinds of waste outside the locality from where it can be removed by municipal authorities. This minimalist system ensures cleanliness and basic upkeep in the community area. The system normally utilises a sweeper and basic waste-collection tools such as a wheelbarrow improvised for waste collection, hand tools and collection bins used by households for routine collection. A community mobilisation effort is required for the efficient working of such a system. In two low-income communities in Karachi, this approach was applied by a local non-government organisation (NGO), the Association for Protection of Environment (APE), in 1996. After providing continuous professional support for three years with the objective of acting as a catalyst, APE trained several members of the local community-based organisation (CBO) to manage and run the project on an independent basis. This paper provides an account of the approach and the system that evolved from it. After withdrawal of the NGO in 2000, the project has been working successfully under the supervision of the local CBO and area youth. This paper presents the lessons learned from the process of empowering communities to develop their own internal service systems. It addresses the issues that are vital in ensuring the sustainability of such attempts in urban lower-income localities.
Modelling tunnelling-induced settlement of masonry buildings
Authors: Burd H. J. , Houlsby G. T. , Augarde C. E. , Liu G.
Published: November 2009

Current practice for assessment of settlement damage to buildings due to tunnel construction usually starts with a procedure in which greenfield settlements are imposed on a structual model of the building. This process ignores the important interaction effects that the weight and stiffness of the building have on the settlements. This paper describes a three-dimensional finite element analysis in which the tunnel, the soil and a building are all treated in a single analysis. Example calculations are described, and these indicate that interaction between the building and the ground can have a significant effect on the extent of the predicted damage. The performance of the building is seen to be highly dependent on whether the settlements induce a sagging or hogging mode of deformation. The analyses are used to plot contours of soil surface settlement and also expected crack patterns within the building.
The use of field geophysical techniques to determine geotechnical stiffness parameters
Authors: Matthews M. C. , Clayton C. R. I. , Own Y.
Published: November 2009

Recent advances in our knowledge of the geotechnical behaviour of natural soils and weak rocks suggest that the shear stiffness controlling wave propagation in near-surface materials will be similar to those which geotechnical engineers wish to measure, and use to calculate movements of the ground around engineering structures. Field seismic techniques which have been found suitable for stiffness determination are reviewed. The benefits of using geophysical methods, as compared with the use of routine geotechnical techniques, are discussed.
Pilot in situ auger mixing treatment of a contaminated site. Part 3. Time-related performance
Authors: Al-Tabbaa A. , Evans C. W.
Published: November 2009

This paper, part 3 of a series of publications, presents a laboratory assessment of an in situ auger mixing treatment of a contaminated site up to 28 months after treatment. Part 1 detailed the site conditions and treatability study work and part 2 detailed the auger development and the site trial. The laboratory assessment was carried out in terms of physical and chemical properties, namely unconfined compressive strength, durability, permeability, compressibility, leachate pH, X-ray diffraction and scanning electron microscopy. The time-related behaviour of the seven mixes used was investigated and compared at two, 14 and 28 months after treatment and assessed in relation to the design criteria set at 28 days. This paper presents evidence of time-related behavioural changes and of the complexity and site-specific nature of the problem. It also emphasizes the time-liness of research work on long-term behaviour of stabilized/solidified contaminated ground to improve the efficiency and cost-effectiveness of the treatment methodology.
Drained shear strength of fine-grained soil–solid surface interfaces
Authors: Subba Rao K. S. , Allam M. M. , Robinson R. G.
Published: November 2009

Herein are reported the results of an investigation on the effective angle of interfacial friction between fine-grained soils and solid surfaces as influenced by the roughness of the material surface, the soil type and the overconsolidation ratio. The ratio of interfacial friction angle to the angle of internal friction (evaluated at constant overconsolidation ratio) of the soil is independent of the overconsolidation ratio. An empirical correlation between this ratio and the roughness of the interface has been proposed.
Relationships between shaft capacity of driven piles and CPT end resistance
Authors: Lehane B. M. , Chow F. C. , McCabe B. A. , Jardine R. J.
Published: November 2009

Potential relationships between the shaft capacity of a pile driven in clay and the cone penetration test (CPT) end resistance are investigated using results from recent field research on displacement piles. It is shown that a relatively good correlation between shaft capacity and cone end resistance may be achieved if other influential parameters such as interface friction angle, clay sensitivity and relative depth of the pile tip are taken into account. The proposed approach is seen to provide good predictions for a range of pile test results and is both compatible with, and an improvement on, existing CPT-based methods.
Load/settlement prediction for large-diameter bored piles in Mercia mudstone
Authors: Delpak R. , Omer J. R. , Robinson R. B.
Published: November 2009

A semi-empirical method has been developed which can predict the characteristics of large-diameter, bored, cast in situ piles in Mercia mudstone, at every stage of loading up to the ultimate state. The analysis is based on mathematical representation of: (a) the mobilization of shaft resistance and end bearing with increasing pile settlement; (b) the variation in load sharing between the pile shaft and base; (c) where present, the additional influence of compressible soil debris on settlement at pile base level; and (d) the effect of nonlinear stress–strain behaviour of concrete on pile compression, hence settlement. The predictive method has been validated against a large database of full-scale pile tests in Mercia mudstone and other cohesive soils. The database comprised test piles with or without instrumentation and having a wide range of diameters and lengths. In every case, the predictive capability is judged to be accurate and satisfactory. The method is also capable of dealing with special circumstances whereby a pile is specifically constructed to support load purely in shaft resistance or end bearing. The improved predictive capability of this method, in pile analysis, is expected to result in a more cost-effective construction.
Integrity testing of pile foundations using axial vibration
Authors: Lilley D. M.
Published: November 2009

Construction of cast-in-place concrete piles can be susceptible to problems which in severe cases can produce failure of the foundation under applied load. This type of foundation is formed by drilling a substantial hole into the ground, placing steel reinforcement and filling with wet concrete. Several well-documented cases exist where concrete has not completely filled the hole and substantial voids have formed within the pile. Receptance theory has been developed to enable the nature, size and position of a finite defect within a suspect pile to be identified. The technique requires three axial resonant frequencies to be obtained from in situ vibration tests (after the concrete has hardened), and nominal dimensions and material properties of the pile. The application of the theory is demonstrated using data relating to a pile with a known defect. The theory described in this paper ignores the effect of the surrounding soil: guidance is given so that this can be included by further development of the theory.
Geotechnical aspects of lifeline engineering
Authors: O'Rourke T. D. , Stewart H. E. , Jeon S.-S.
Published: November 2009

The general principles of lifeline engineering are discussed and applications are illustrated with reference to pipeline networks. Key research findings are summarised regarding the effects of utility construction on existing pipelines, advanced backfilling methods and materials, and soil-structure interaction of polyethylene pipelines. Pipeline behaviour during earthquakes is reviewed with respect to the effects of permanent and transient ground deformation. Pipeline system performance is addressed in light of geographic information systems (GIS) and the observed behaviour and analysis of large networks during recent severe earthquakes.
Managing geotechnical risk: time for change?
Authors: Clayton C. R. I.
Published: November 2009

Ground-related factors have often been the cause of significant time and cost overruns on both large and small construction projects. The traditional method of controlling such risks has been through the use of thorough ground investigation and competent geotechnical design, aiming to produce a robust scheme, well-matched to the expected ground conditions. This paper reanalyses data collected over the past two decades and suggests that, particularly in view of rapidly evolving methods of construction procurement, a new risk-based approach is needed. Key elements of this approach are outlined.
Land reclamation technology—expanding the geotechnical engineering envelope
Authors: Dawson G. W. , Gilman J.
Published: November 2009

Early approaches to land reclamation involved bulk removal of contaminated media using traditional geotechnical engineering technologies such as soil excavation and groundwater extraction. While these methods rely on readily available equipment and can be applied to a broad spectrum of contaminants, they are less than ideal. In the case of soil excavation, the approach is effective, but treatment is costly. Depending on the alternatives available, this approach may do little more than move the contamination from one site to another. With respect to groundwater extraction, the approach has proven to be very inefficient in many settings and requires extremely long time frames to complete. As a consequence, new technologies have emerged which attempt to exploit the chemical properties of contaminants to facilitate removal or destruction. The more developed of the new approaches are characterised in this paper, including how they work, how they are applied, potential limitations, and results from specific applications. While many of these new technologies have improved our ability to reclaim the land, significant limitations still leave undesirable results in terms of residual contamination and remedy cost. There is a need to continue improving and developing new technologies, especially those related to non-volatile contaminants and dense, free-phase liquids.
Lumped parameter modelling of single-tendon ground anchorage systems
Authors: Ivanovic A. , Neilson R. D. , Rodger A. A.
Published: November 2009

Research into the static and dynamic performance of ground anchorage systems has been in progress at Aberdeen University since the early 1980s. This programme has involved computer and laboratory modelling in conjunction with measurements on active construction sites. Latterly the work has concentrated on investigating resin bonded rock bolt anchorages and has led to the development of a new method for the non-destructive testing of anchorages. As part of the programme research was undertaken to assess how changes in the material properties of the resin grout and the presence of debonding/grout defects influenced anchorage dynamic response. To that end a lumped parameter model has been developed to simulate anchorage dynamic response. The acceleration response was examined at a number of points in the anchorage system i.e. at the protruding length as well as at the anchorage head, along the free length, along the fixed length and even within the rock mass itself. A parametric study was then undertaken with regard to changes of material properties of the resin and the introduction of defects such as debonding. The following paper presents results which have arisen to date from the analysis undertaken on this preliminary numerical model.
The observational method can be simple
Authors: Peck R. B.
Published: November 2009

This paper describes three examples—the Chicago Subway, the Cleveland Ore Yard and the Newport News Shipway—where quite simple field observations led to substantial improvements. These projects were forerunners in the application of the observational method and they reveal how elemental theory and qualitative predictions form the essence of the observational method.
Environmental regulation of groundwater abstraction for dewatering works
Authors: Preene M. , Brassington F. C.
Published: November 2009

The abstraction of groundwater for beneficial use or supply in England and Wales is restricted by law. The relevant legislation is currently the Water Resources Act 1991, but the Government has recently announced that new legislation is forthcoming. This paper outlines the licensing system currently in place and goes on to explain the proposed changes to legislation controlling dewatering works. It emphasises that in future it will be essential to keep the Environment Agency suitably informed of groundwater abstractions for whatever purpose and to comply with the new regulations, as failure to do so may well result in prosecution.
Widening and deepening adjacent large shafts in rock
Authors: Antonio E. C. , Adams N. L.
Published: November 2009

The influent pumping station (IPS) at Bandra plays a key role in the Mumbai Sewerage Scheme. Bandra IPS will be one of the largest pumping stations of its type in the world, with a pumping capacity of nearly 22 m3/s. The rock support scheme for the widening and deepening of three existing shafts is described, with particular attention being given to the scheme for the narrow zone of rock between the two pump shafts, termed the ‘narrow neck’. Inherent site conditions and the demands of a new station on a prescribed station layout have placed unusual constraints on the customary rock support methodology. Several excavation and rock support alternatives are discussed and the limitations of routine design methods are highlighted. The finally agreed scheme was a progressive and carefully planned rock support and excavation sequence that considered the possibility of localised instability during the excavation works and provided contingencies for several possible events. A concrete bridge was constructed to restrain the existing retaining walls and through-going grouted bolts continuously supported the whole rock section, before, during and after excavation. Inspection and monitoring was completed before each stage of excavation. The rock face and retaining walls remained intact and no serious failures were experienced during excavation. A brief discussion of possible rock design alternatives, given a virgin site of similar rock, follows the conclusions. Rock excavations are now complete and the civil works at Bandra IPS are nearing completion.
The effects of hydrocarbon contamination on concrete strength
Authors: Wilson S. A. , Langdon N. J. , Walden P. J.
Published: November 2009

The development of brownfield sites often requires foundation concrete to be placed in contact with soils contaminated with hydrocarbons. There is a common perception that the hydrocarbons affect the setting and hardening of the concrete, giving a reduced long-term strength. There is however limited quantitative data to support this view. Laboratory testing of concrete cubes cured in various hydrocarbon compounds has been undertaken. The results indicate that hydrocarbons do reduce the long-term strength gain of concrete by up to 25%. This can be allowed for in design, thus avoiding the need for expensive sleeving or surface protection systems. Available evidence suggests that the effects of petroleum hydrocarbons on hardened concrete, which has achieved its design strength, are of limited concern. Creosote, however, can affect hardened concrete that has achieved its design strength. Where hardened concrete is likely to come into contact with creosote derived contamination then again a reduction in long-term strength should be considered.
Briefing: Foundation piling—steel to replace concrete
Authors: Dawson R.
Published: November 2009

Changes affecting construction arise from many sources, at random times and without coordination. It is necessary to re-evaluate construction practice to take account of these factors. Change may be driven by Government through legalisation, by equipment manufacturers, by client demand and many other forces. Foundation piling is in need of re-evaluation.
Briefing: Factored material properties and limit state loads—unlikely extreme or impossible pretense
Authors: Day R. A.
Published: November 2009

In the limit state design (LSD) method each design criterion is formally stated and assessed using a performance function. The performance function defines the relationship between the design parameters and the design criterion. In practice, LSD involves factoring up loads and factoring down calculated strengths and material parameters. This provides a convenient way to carry out routine probabilistic-based design. The factors are statistically calculated to produce a design with an acceptably low probability of failure. Hence the ultimate load and the design material properties are mathematical concepts that have no physical interpretation. They may be physically impossible. Similarly, the appropriate analysis model is also defined by the performance function and may not describe the real behaviour at the perceived physical equivalent limit condition. These points must be understood to avoid confusion in the discussion and application of partial factor LSD methods.
Briefing: Rainfall-induced landslides in Singapore
Authors: Toll D. G.
Published: November 2009

Minor, shallow landslides have occurred frequently on the island of Singapore. However, very few major landslides (greater than 10 m in height) have occurred. Slope failures in the sedimentary Jurong and granitic Bukit Timah formations have occurred largely on slopes with angles greater than or equal to 27°. It is clear that rainfall has been the dominant triggering event for landslides in Singapore. Observations of past landslide events suggest that a total rainfall of 100 mm within a six-day period is sufficient for minor landslides to take place. The equivalent condition for major landslides would appear to be 320 mm within 16 days but this is based on very limited data.
Elsewhere in ICE Proceedings
Authors: Bond A.
Published: November 2009

The following papers—published in other parts of ICE Proceedings—cover topics that readers of Geotechnical Engineering may find of interest.
Undrained analysis of earth berms as temporary supports for embedded retaining walls
Authors: Daly M. P. , Powrie W.
Published: November 2009

Earth berms can provide an effective and economic means of enhancing the short-term stability of an embedded retaining wall but there is no generally accepted procedure for determining their effectiveness. In this paper, various methods of representing an embedded retaining wall supported by an earth berm in an undrained limit-equilibrium analysis are discussed. Comparison with the results of centrifuge model tests shows that these methods are conservative to a greater or lesser extent and a more rigorous approach is developed. Procedures are then set out that may be used to assess the short-term safety and stability of a stiff, berm-supported embedded retaining wall in overconsolidated clay.
Briefing: Geotechnical engineering and building research: the early days of soil mechanics at BRS—Part 3, 1944–1948
Authors: Penman A. D. M.
Published: November 2009

An essay on the foremost British government soil mechanics laboratory from earlies times to 1957.
Finite-element analysis of a compensation grouting field trial in soft clay
Authors: Addenbrooke T. I. , Ong J. C. W. , Potts D. M.
Published: November 2009

This paper presents the details of, and results from, finite-element modelling of a monitored field trial of compensation grouting in Singapore Marine Clay. The numerical results are compared with the ground surface response and the pore water pressures that were monitored during the trial grouting programme. Notable features of the field trial were that: (a) the ground heave achieved during a one-day grouting cycle reduced during the subsequent three-day rest period before the next grouting cycle commenced; and (b) the excess pore water pressures generated during that one-day grouting cycle dissipated to almost zero during the three-day rest period. The Imperial College Finite Element Program was used to analyse this field trial. The method for the modelling of compensation grouting is described. Two alternative grout propagation models are compared, one of which produces a good match with the field recorded heave data, and the other with the field recorded pore pressure data. The hydraulic boundary conditions are also varied to look at the consolidation behaviour. It is concluded that the proposed finite-element model can reproduce field behaviour if excess pore pressures can dissipate to the injected grout itself. The analyses also suggest that the direction of grout propagation in the field probably varies as the grout is pressurised.
Active and passive earth pressure coefficients by a kinematical approach
Authors: Soubra A.-H. , Macuh B.
Published: November 2009

A simple method is proposed for calculating the active and passive earth pressure coefficients in the general case of an inclined wall and a sloping backfill. The approach used is based on rotational log-spiral failure mechanisms in the framework of the upper-bound theorem of limit analysis. It is shown that the energy balance equation of a rotational log-spiral mechanism is equivalent to the moment equilibrium equation about the centre of the log-spiral. Numerical optimisation of the active and passive earth pressure coefficients is performed automatically by a spreadsheet optimisation tool. The implementation of the proposed method is illustrated using an example. The predictions by the present method are compared with those given by other authors.
Monitor: Soils and Foundations
Authors: Hope V.
Published: November 2009

Published by the Japanese Geotechnical Society, Tokyo. Six issues per annum; circa 150 pages per issue. Current subscription: 9000 yen. ISSN 0038-0806.

Soils and Foundations is the international, English-language journal of the Japanese Geotechnical Society. In general, the journal tends to focus on the needs and interests of researchers rather than of practitioners. Most papers are concerned with soil properties and laboratory-based techniques, although dynamic problems, earthquakes and foundations are regular topics, and there is a steady interest in underground structures. Papers on site investigation appear relatively infrequently, and few papers deal with rock mechanics. The following brief selection from recent issues of Soils and Foundations summarises those papers that perhaps have an immediate practical relevance, rather than the more academically oriented papers.
Monitor: Recently in Géotechnique
Authors: Bond A.
Published: November 2009

The following are a selection of papers published recently in Géotechnique that readers of Geotechnical Engineering may find of particular interest. The selection concentrates on applied rather than pure research topics and covers issues published from September 2001 to March 2002.
Briefing: What is the matter with geotechnical engineering?
Authors: Atkinson J.
Published: November 2009

In this essay the author argues that education in the basic theory of structures, hydraulics and geotechnics is being neglected in favour of training in the practical aspects of geotechnical engineering and an over-reliance on design codes and standards.
Pilot in situ auger mixing treatment of a contaminated site. Part 4. Performance at five years
Authors: Al-Tabbaa A. , Boes N.
Published: November 2009

Parts 1, 2 and 3 of this series of publications gave details of the development and application of a pilot in situ auger mixing treatment on a contaminated site in West Drayton, Middlesex. The treatment method employed was in situ stabilisation/solidification using cement-based grouts and applied using a soil-mixing auger. In these publications, details were given of the initial laboratory treatability study, the site trial and subsequent laboratory assessment of the treated contaminated made ground using samples cored at 55 days and tested at 0·2, 1·2 and 2·4 years after treatment. Recently, further coring of the treated ground took place at 4·5 years of in situ curing and the samples were tested at around 5 years after treatment. Hence this paper presents the longer-term behaviour of the in situ cured stabilised/solidified contaminated ground in terms of physical and chemical properties such as strength, leachability, leachate pH, permeability, freeze–thaw and wet–dry durability and microstructural analyses. The performance is presented of both soil types present, made ground and sand and gravel, from both single and overlap column mixes. The paper provides an insight into the effectiveness of the treatment at 5 years, a correlation between the performance of the different soils and mix conditions, and an assessment of the applicability of the available test methods and test criteria imposed.
Groundwater control for construction in the Lambeth Group
Authors: Preene M. , Roberts T. O. L.
Published: November 2009

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.
Briefing: Embedded retaining walls: guidance for economic design
Authors: Gaba A. R. , Simpson B. , Beadman D. R. , Powrie W.
Published: November 2009

CIRIA Funder's Report CP96 was issued to the core members of CIRIA in March 2002. It is now, or will shortly be, available to a wider audience. This note describes the background to this research project and details the objectives, intended readership and applicability of the resulting report. The report particularly addresses the subject of economic design, and some of the key recommendations are noted below.
Vertically loaded shallow foundation on soft clayey silt
Authors: Lehane B. M.
Published: November 2009

This paper presents the results from a field experiment involving the vertical loading to ultimate failure of a shallow pad footing founded on a soft estuarine clayey silt. Data from settlement plates and pneumatic piezometers located beneath the footing are used, in conjunction with estimated stress distributions, to compare the ground's stiffness characteristics with those measured in laboratory tests. The operational undrained shear strength of the clayey silt, inferred from the ultimate vertical load of the foundation, is also compared with in situ and laboratory estimates of undrained shear strength and with operational strengths estimated from a similar footing test. The paper presents the results from a prediction competition held for the footing experiment with a view to assisting assessment of the reliability of standard design prediction procedures.
Partial factors and non-linear ground–structure interaction
Authors: Lo S. R.
Published: November 2009

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.
Determination of parameters for a hyperbolic model of soils
Authors: Al-Shayea N. , Abduljauwad S. , Bashir R. , Al-Ghamedy H. , Asi I.
Published: November 2009

Analysis of some geotechnical problems using finite-element methods requires the implementation of a nonlinear model for soil materials, to better represent their actual behaviour. Constitutive modelling of soil mass behaviour and material interfaces is an essential component of the solution of boundary and initial value problems. The hyperbolic model is one of the most frequently used non-linear models for predicting the behaviour of soils in boundary value problems. The parameters of this model for specific soils need to be determined experimentally. This paper presents the results of extensive laboratory testing carried out on three soils from the Eastern Province of Saudi Arabia: sand, marl and sabkha. The tests used to obtain these results were the triaxial compression test, the hydrostatic (isotropic compression) test, and the direct shear test. Additionally, other tests were used to obtain various physical properties needed for the complete characterisation of these soils. Parameters of the hyperbolic models for non-linear tangent Young's and bulk moduli are presented. These parameters compare well with those reported in the literature. They are incorporated in the hyperbolic model and used to back-predict the stress–strain behaviour of the investigated soils. The calibrated models are found to predict soil behaviour very well.
Sustainable chalk fill transfer from Channel Tunnel Rail Link
Authors: Phear A. , Patterson D. , Warren C.
Published: November 2009

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.
Tunnelling through varying soil conditions in north-west Greece
Authors: Georgiannou V. N.
Published: November 2009

Tunnel S2 of the Egnatia Motorway is excavated through heavily fractured limestone and sheared sediments. Originally a fold and thrust belt was formed in the Alpine orogenic phase. Post-orogenic tectonics resulted in heavy fragmentation. The underlying material consists of clays and clayey sandy gravels. The basement of the clastic formation consists of evaporites. This variety of geological conditions resulted in considerable variability of tunnelling conditions and the need for extensive primary support measures. Owing to the mixed and rapidly changing geological conditions the type and intensity of primary support measures were selected according to geomechanical conditions at the crown. Slope stability problems were encountered during the excavation of the entrance portal, and because of the associated risk an additional study has been carried out to determine appropriate soil parameters for the excavation works through such a medium. Oedometer tests and direct shear tests were carried out to investigate the susceptibility of the material to structural breakdown and to define peak and post-rupture strength characteristics.
Briefing: Embankment cuttings: condition appraisal and remedial treatment
Authors: Perry J. , Pedley M. , Brady K. , Reid M.
Published: November 2009

CIRIA Report C550 Infrastructure Embankments: Condition Appraisal and Remedial Treatment was published in 2001 and has proved to be one of CIRIA's most popular documents. Such was the demand for it, CIRIA commissioned the same team to produce a similar report on cuttings to the same format and targeted at the same audience. The cuttings report (CIRIA Report C591) is to be published in the winter of 2003, and an updated version of the embankment report (CIRIA Report C592) is also to be published at the same time, launching both geotechnical asset documents as a companion pair. This briefing note describes the background to the research projects and details their purpose, intended readership and the main aspects of managing geotechnical assets. The reports are intended to present best practice and to raise awareness of these important structures to the operation of an efficient transport network.
Settlement and tilt of low-rise buildings
Authors: Charles J. A. , Skinner H. D.
Published: November 2009

Where deep foundations are not an economically viable solution, foundation problems may occur at low-rise housing developments on poor ground. It is usually feasible to provide a raft foundation relatively cheaply for lightly loaded buildings. When differential settlement occurs, foundations of adequate stiffness will cause the building to tilt as a rigid body, and will prevent significant distortion of the building and consequent cracking of the walls. A number of case histories of tilted buildings are presented to illustrate the magnitude of tilt that has been observed with different ground conditions, and the remedial actions that have been undertaken. Noticeability is a key factor in assessing the acceptability of tilt for low-rise residential buildings and their occupants, and tilt typically is noticed when it is in the region of 1/250 to 1/200. Where tilts of the magnitude of 1/100 or greater are measured, or the measured rate of increase of tilt indicates that this degree of tilt will be exceeded, some remedial action should be taken, which is likely to include re-levelling the building.