Drilled pier foundation practice for highrise buildings in Montreal, Canada

Drilled pier foundation practice for highrise buildings in Montreal, Canada

186A 923366 Behavionr of statically loaded piles embedded in a soil with cyclically vary~g effective stress Hanna, T H; AI-Jumaily, F A Proc NLqth Dam...

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186A 923366 Behavionr of statically loaded piles embedded in a soil with cyclically vary~g effective stress Hanna, T H; AI-Jumaily, F A Proc NLqth Damdk,-European Conference on Soil Moclmics amt Fmmdatioa Emgineeriq, Bmlapest, 2-5 October 1990 1'211-217. Publ Budapest: Akademiai Kiado, 1990

92337O Bearing capacity determination of deep foundations in Bratisinva and other towns Matys, M; Werdenich, K Proc Ninth Datmbe-Ewopean Conference on Soil Meclumics and Fmmdation Eagi~eriag, Bmdapest, 2-5 October 1990 1'259-264. Publ Budapest: Akademiai Kiado, 1990

An instrumented model pile was installed in dry sand in a test chamber. Constant axial load was maintained on the pile, while effective stress in the soil mass was varied by applying a surcharge load to the surface using a special loading plate. Distribution of axial load and pile friction and pile tip movement were monitored during the cycling of soil effective stress. Load distribution around the pile changes during the cycling. Reasons for this are examined. Bearing capacity in compression increases during cycfing, but pullout resistance is little affected.

Many large structures are founded on piles in Bratislava. The underlying soils are predominantly medium compact to loose alluvial deposits and neogene sediments. Two methods used to assess bearing capacity are described. The first involves loading the pile using a specially designed cylindrical tank, which is held in place by anchors, and filled in stages with water to apply load. The second is used where transport of the tank is difficult. Bearing capacity is calculated according to a formula by Menard (1975) with the shaft friction contribution evaluated from pressuremeter test data.

923367 Drilled pier fonndation practice for highrlae buildings in Montreal, Cmugin Ladanyi, B; Bensoussan, A; Castongnay, J; Tommasel, A M Proc Ninth Damabe-Europetm Conference on Soil Meelta~s amt Foundation F a ~ e r i a g , Bmlapest, 2-5 October 1990 P239-246. Publ Budapest: Akademiai Kiado, 1990 Much of urban Montreal is underlain by thick glacial till over sub-horizontally bedded shales and limestone at depths 1315m. Drilled piled foundations, socketed into bedrock, are used for most tall buildings with basements. The pile design codes, considering load partitioning between shaft and base, and where each of these is applied are described. Two case studies are presented where bedrock RQDs were 0% and 2555% respectively, and the applicability of the designs adopted is discussed. 923368 New foundation method of motorway bridge on the River Danube Lakatos, E; Apathy, E; Encsy, B; Hlatky, K; Gyorgy, P Proc Ninth Danbe.European Conference on Soil M e c k a ~ s and Fomulation ~ g , Bmdapest, 2-5 October 1990 P247-251. Publ Budapest: Akademiai Kiado, 1990 The new Danube bridge has three piers situated in the riverbed. Traditional and modem methods of construction were considered before a novel technique was chosen. Following dredging of the riverbed, it was deepened by 0.5m to make a flat area for a precast concrete bottom member. Bored, cast in place piles were constructed using guide rings in the bottom member to aid location. An upper precast member placed on the pile heads takes a concrete slab on which the piers are built.

923371 Underpinning on expansive soils - a ease history Uriel, A O; Ortuno, L; Puebla, J Proc 6tk Imermuiomd Confereoce on Expamive Soils, New DelM, 24 Nocember-4 December 1987 V2, P611-614. Publ Rotterdam: A A Balkema, 1991 Severe damage was exhibited at a structure founded at depth 2.5m in high plasticity marly clay with swelling pressures up 875kPa. Trees have desiccated the ground, causing settlement, and, following their removal, expansive movements are expected. Underpinning is the chosen remedial measure, with a concrete beam used to transmit structural loads to deep concrete piers, the high contact pressures minimising movement. The piers are at depth 5m, below the most desiccated zone. A gap is left between soil surface and beam base to accommodate swelling movement.

Dams and embankments See also: 923188 923372 Constructions of multi-purpose dams in Japan In: Rock Moclmaics ia Japan, Volm~ VI P36-39. Pubi Tokyo: Japanese Committe for ISRM, 1991 Over 300 dams, mainly concrete gravity structures, have been completed in Japan for flood control and water supply, and some 400 more are planned. The scarcity of tight bedrock for foundations has led to requirement of rigorous site investigation. The typical case of the Miyagase Dam is described, where 5300m of geophysical prospecting was supplemented by 16 in situ deformation and 25 in situ shear tests, core drilling (87 holes), permeability tests (73 holes), and 19 exploratory adits. The roller compacted cement for dams (RCD) construction method is favoured on grounds of quality, economy, and safety.

923369 Analysis of drilled piers aettlemeats with non-linear deformability of the soils Malyshev, M V Proc Nimk Daube-Em'opean Conference on Soil M e e k a ~ s and Fomulation F ~ i ~ ' i ~ g , Bmlqest, 2-5 October 1990 1'253-258. Publ Budapest: Akademiai Kiado, 1990

923373 ReassesmmM of the causes of the Candngton emlmnkmont failure Rowe, P W Geoteelmiqnc ;/41, N3, Sept 1991, P395-421

An analysis is presented for the load-settlement behaviour of piles which includes both the end bearing and shaft friction components of bearing capacity. Settlement against load is evaluated both for the initial linear period where the soil behaves elastically and in the region of plastic deformation. The point of onset of plastic deformation, where bearing capacity is effectively lost, is examined.

Further data on the 1984 Carsington failure have been made available for analysis. They indicate an unusual mechanism of articulated shears commencing within the base of the mudstone fills along shear planes built in at the centre of the valley during early stages of construction. Initiation and procedure of the process, culminating in collapse at the side dragging the centre into failure, are explained. The basic cause can be

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