Effect of backfill properties and surface treatment on the capacity of adfreeze pipe piles. Technical note

294A The Zagros mountains consist of folded sequences of limestone covered by alternations of sandstones, clays and marls interbedded with evaporites, all modified by tectonics and surface erosion. Initial stability and stability after road construction were considered. Some major problems arose due to slope stability and swelling of soft marls of tunnel floors. 905317 High capacity piles in a region of ancient underground quarries (In French) Simon, B; Schlosser, F; Morey, J Proc 1st lnternatiomd Geoteclmical Seminar on Deep Fomulations on Bored and Auger Piles, Ghent, 7-10 June 1988 P349-361. Publ Rotterdam." A A Balkema, 1988 Extension of the Montparnasse station in Paris required high capacity foundations to support a very rigid structure. Ancient underground limestone quarries are present in the area at about 20m depth. Some galleries are filled, and some have collapsed leading to cavities in the overlying marls. Methods used to evaluate the horizontal stiffness of the required support, design and construction of the bored, cast in situ piles, and filling of the cavities and galleries are described.

Base courses and pavements 905318 Polymer grid reinforced pavement on soft clay grounds Miura, N; Sakai, A; Taesiri, Y; Yamanouchi, T; Yasuhara, K Geotext Geomem vg, NI, 1990, P99-123 Model and field tests were used to investigate mechanisms of polymer grid reinforcement in supressing differential settlement of pavements on soft clay ground. Finite element deformation analysis was used to clarify the mechanism. Field tests used a 300m length of pavement with six different sections. The effect of grid type and function of the grid are discussed. 9O5319 Expanded polystyrene - a superfight fill material Frydenlund, T E; Aaboe, R Proc lnternatioaal Geoteclmical Symposium on Theory and Practice of Earth Reimforcement, Fukuoka Kyushu, 5-7 October 1988 P383-388. Pub/Rotterdam." A A Balkema, 1988 The use of expanded polystyrene (EPS) as a lightweight fill in Norway is described. Advantages due to very low density and ease of handling are considered. Chemical degradation is prevented by casting a layer of concrete over the EPS. Case studies illustrate the use of EPS in pavements, a bridge abutment, and a vertical retaining wall. Possible future applications are examined.

Foundations See also: 905209. 905213 905320 Stretlllilue soletlon for rigid laterally loaded piles in permafrost Foriero, A; Ladanyi, B Can Geotecll J V26, N4, Nov 1989, P568-574 Laterally loaded piles in frozen soils behave as rigid piles in the long term, and rotate about a fixed point in the soil mass as a result of soil creep. A design method using a streamline solution technique developed in ice mechanics to predict ice loads on structures is presented. The pile is modelled as a rigid

disc moving laterally in a nonlinear viscoelastic material. A power law rate dependence of creep is assumed. The analysis is valid only for secondary creep and stationary state of stress. 905321 Effect of backfill properties and surface treatment on the capacity of adfreeze pipe piles. Technical note Sego, D C; Smith, L B Can Geotech J V26, N4, Not" 1989, P718-725 Adfreeze pipe piles are formed by inserting steel pipe in a prebored hole in permafrost, and backfilling the anulus with sand slurry or water, which freezes. Adfreeze bonding between backfill and pile provides pile capacity. Model tests indicate that properties of backfill (ice content, salinity, anulus width) have a greater influence on pile capacity than natural soil properties. Nonsaline backfill is preferred. In saline soils,natural soil-backfill interface strength may govern pile capacity. Adfreeze strength is significantly influenced by pile surface roughness. 905322 Upper hound to bearing capacity of layered soils. Technical note Florkiewicz, A Can Geotech J V26, N4, Not' 1989, P730-736 An approach to the problem of flat punch indentation into the Mohr-Coulomb layered half space has been developed, based on the kinematical approach of limit analysis. A kinematically admissable plane-strain failure mechanism for a typical two layer system is presented. The ultimate bearing capacity of strip footings obtained from the proposed approach compares well with experimental data available in the literature. Auth 9O5323 Comparison of pile load test methods. Technical note Joshi, R C; Sharma, H D; Sparrow, D G Can Geotech J 1/26. N4, Nov 1989, P742-744 Model piles were driven into sand using slow-maintained load, fast-maintained load, and constant rate of penetration methods. Applied load, point load, and shaft resistance and its distribution were determined. Ultimate failure load was similar for all three methods, and axial force distributions and shaft resistances were effectively identical. The slow-maintained load method, which seems to simulate field conditions, gave the largest settlement for a given applied load. 9O5324 Vibrations due to pile driving - a case study. Technical note Brunning, D F; Joshi, R C Can Geotech J V26, N4, Nov 1989, P745-747 At a site with 3m of granular fill over gravel, 1 im long 300mm H piles were driven close to a 400mm gas pipeline, buried at depth about lm. Test piles were driven at 2m centres, 2.1m from the pipe. Ground vibrations were monitored as each pile was driven. Results are presented. It was concluded that no damage was likely at distances above 1.2m from the pile. 905325 Finite strip analysis of strip footings: horizontal loading Chow, L K; Swaddiwudhipong, S; Phoon, K F Compm Geotech V8, NI, 1989, P65-86 The finite strip method is used to analyse the static and dynamic response of strip footings subject to horizontal load. The two dimensional problem is effectively reduced to one dimension by representing the displacement of the soil in the lateral direction by a suitable choice of trigonometric functions expressed as a Fourier series. This simplified analysis is

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