Slip repairs using reinforced soils. Technical note

27A 871201 Behaviour of fabric- ~ersus fiber-reinforced sand Gray, D H. Al-Refeai. T J Geotech Engng Div .4SCE l/12..\,~', Aug 1986. P8t)4-820 Triaxial tests ~ere used to compare the stress strain behaviour of sand reinforced with several different geotextiles or with randomly distributed discrete fibres. The influences of some test parameters were also in,,estigated. Sand with reinforcement of both types sho~s a number of similarities in constituti,.e beha,,iour, such as existence of a critical confining stress, and strength increases proportional to the amount of reinforcement, and some differences, notably in failure mode. orientation effects and stiffness. Finally, the feasibility' of using fabrics or fibres to improve the bearing capacity of ground improved by stone columns is demonstrated. 871202 Soil randomly reinforced ~ith fibers. Technical note Freitag, D R J Geotech Engng Div .4SCE I l i 2 . N8, Aug 1986, P823-826 Compacted specimens of lean sandy clay containing no reinforcement or 1% by xolume of randomly distributed polymer fibre were prepared ~ith a sufficiently wide range of water content to define the compaction curve. Unconfined compression tests ,acre carried out on these specimens. It is concluded that this reinforcement increases the strength and toughness. Strength gain is about 25% for samples wet of optimum. 871203 Soil nailing: practical applications Guilloux, A: Schlosser. F Froc Symposium on Recent Developments in Ground Improvement Techniques, Bangkok, 29 Nov-3 Dec 1982 P389397. Publ Rotterdam: .4. A. Balkema, 1985 Practical applications of soil nailing, for slope stabilization and soil retaining structures, are examined. After a short description of the techniques and the design method used, some case histories are described, which emphasize the major factors governing the design and behaviour of these structures. For slope stabilization, the relatixe stiffness of the bars is of great importance, whereas for retaining structures, the lateral friction between soil and bar is the governing parameter. In both cases, the deformations of reinforced soil must be analysed carefully~ Auth, 871204 Behaviour and design of soil nailing Schlosser, F Proc S:vmposium on Recent Developments in Ground Improvement Techniques, Bangkok, 29 Nov-3 Dec 1982 P399413. Pub/ Rotterdam. .4. A. Balkema, 1985 Some considerations on the behaviour and on the soil-bar interaction in soil nailing are presented. A failure design method adopted both for nailed soil retaining walls and for slope stabilization is described. Finally, applications to actual structures and back analysis of faiture cases are given. 871205 Reinforced soil techniques for the reinstatement of failed slopes using geogrids. Technical note Oliver, T L H Proc Symposium on Failures in Earthworks, London, 6-7 March 1985 P417-419. Publ London: Thomas Telford, 1985 Two case studies are presented ,:,'here geogrid reinforcement of failed slopes has proved an economic alternative to soil replacement by granular fill. The first was a London Clay road

embankment, where the soil v~as excavated, replaced and compacted in layers. The second was a very steep slope in hillwash material, which was reconstructed as a terraced wall behind formwork, thus preventing the disruption which would have occurred if a sheet piled or traditional gravity ~all were used. 871206 Slip repairs using reinforced soils. Technical note Jewel1, R Proc £:l'mposium on Failures in Earthworks, London, 6-7 March 1985 P420-423. Publ London: Thomas Te#brd. 1985 The cases where reinforced soil can be used for repair work are described: (1) recompaction after a shallow translational slip in an embankment as an alternative to soil replacement: (2) remedial measures for long term stability of slopes steepened by surface or toe erosion, and where relic ~eakness and groundwater influence stability: and (3) short term stability of an embankment after construction, where foundations of overconsolidated clay include a relic weak plane, and failure is possible until excess pore pressures generated during construction have dissipated.

Soil stabilisation SeE' also: 871003 871207 Method of reducing the cement content of two stabilised Niger delta soils Akpokodje. E G Q J Engng Geol VI9, N4. 1986, P359-363 Cernent is an effective agent in stabilizing the fine grained Niger delta soils to provide base course material for roads. The amount of cement required to stabilise the clays/silty clays and uniformly graded medium to fine sand can be reduced by as much as 50% if the two soil types are mixed in equal proportions (1:1 ratio) before cement stabilisation. Auth. 871208 Engineering properties and behaviours of stabilized compressed tropical soils. Technical note Ola, S A Q J Engng Geol V19, N4, 1986, P425-431 Work to date on cement stabilised compressed tropical soils (Soilcrete) as a brick-making material is summarized. Compaction effects are seen to be more important than cement content of the compressed block, although a limiting pressure is found above which tensile or compressive strengths are not significantly influenced. Block shape influences crushing resistance. Recommendations are made for compaction pressure, composition.and minimum wet and dry uncured strengths to optimise block properties and economic benefits.

871209 Deep chemical mixing method using cement as hardening agent Suzuki, Y Proc Symposium on Recent Developments in Ground -Improvement Techniques, Bangkok, 29 Nov-3 Dec 1982 P299340. Publ Rotterdam: A. A. Balkema, 1985 A deep mixing method, using cement slurry as a hardening agent, is presented as a new method of soil stabilization, with emphasis on the following details: necessity of Deep Chemical Mixing method (DCM) method: outline of DCM method: material for the method: engineering characteristics of improved soil; design of improved ground: and execution.

(" 1986 Pergamon Journals Ltd. Reproduction not permitted