Load tests of large diameter caissons for a high rise building in Singapore

249A 934335 Failure of discontinuous rock masses under surface loads Tutluoglu, L Proc Conference on Fractured and Jointed Rock Masses, Lake Tahoe, 3-5 June 1992 P319-326. Publ California: Lawrence Berkeley Laboratory, 1992 Failure analysis is presented for the case of a half space, representing a rock mass containing a horizontal discontinuity set or regularly spaced bedding, under a circular loaded area. Tensile and compressive failure depths and corresponding pressures are evaluated and the influence of discontinuity spacing and stiffness on these values investigated. A simple model is developed to simulate lateral expansion of the dilatant zone around the optimum failure point and to predict the bearing capacity of bedded rock. 934336 Minimizing swell pressure by sand cone replacement Sabbagh, A O; Abuzaid, A A Proc Ninth Asian Regional Conference on Soil Mechanics and Foundation Engineering, Bangkok, 9-13 December 1991 II1, P159-162. Publ Thailand: Southeast Asian Geotechnical Society, 1991 The expansive soils of Saudi Arabia have been characterised and montmorillonitic silty clay from Madinah found to have the highest swell potential. The effects of replacing part of the soil beneath a footing by a sand cushion or sand cone have been examined in model tests. A range of sand replacement configurations was used. Optimum sand cone diameter and angle have been evaluated. Pressure on the footing was reduced by up to 91.5%. 934337 Settlement of inclined loaded footings on sand layers Ameen, S F Proc Ninth Asian Regional Conference on Soil Mechanics and Foundation Engineering, Bangkok, 9-13 December 1991 V1, P197-200. Publ Thailand." Southeast Asian Geotechnical Society, 1991 Model tests on strip footings on a sand layer over a rough rigid stratum are reported. The experimental system and test procedures are described. Results indicate that for a given load, settlement decreases with decreasing soil layer thickness. For a constant layer thickness, the relation between vertical component of the load and settlement is not affected by load inclination. Currently used methods of settlement prediction underestimate values for small scale model footings. 934338 Load tests of large diameter caissons for a high rise building in Singapore Broms, B B; Han, K K Proc Ninth Asian Regional Conference on Soil Mechanics and Foundation Engineering, Bangkok, 9-13 December 1991 V1, P205-208. Publ Thailand: Southeast Asian Geotechnical Society, 1991

A proposed 66 storey block in Singapore will be founded on 12 large diameter caissons, maximum length 60m, supporting by side friction in bouldery clay underlying the site. To confirm the design, large scale jacking tests were carried out on caisson segments. The shaft and end beating components of resistance were separated using stability plots. The alpha method of evaluating resistance was considered more appropriate than the beta method. The sandstone boulders in the clay adhere strongly to the concrete, contributing significantly to skin friction. Stiffness of the clay evaluated by elastic analysis showed considerable scatter.

934339 Pile loading behaviour under different loading procedures - a finite element simulation Chen, H T; Jan, Y Y; Wu, K C; Li, J C Proc Ninth Asian Regional Conference on Soil Mechanics and Foundation Engineering, Bangkok, 9-13 December 1991 V1, P213-216. Publ Thailand: Southeast Asian Geotechnical Society, 1991

An axisymmetrical finite element procedure is used to model the behaviour of single piles in standard and quick maintained load tests. The viscoplastic nature of the soil is modelled using the theory of Perzyna (1966) and pile-soil interface slip is taken into account. The simulation closely predicts observed behaviour of concrete piles under the quick maintained load test in layered silty clay and silty sand. Bearing capacity predicted for the quick maintained load test is greater than that predicted for the standard test. 934340 Three types of model tests on laterally loaded pile groups Kimura, M; Shibata, T Proc Ninth Asian Regional Conference on Soil Mechanics and Foundation Engineering, Bangkok, 9-13 December 1991 V1, P229-232. Publ Thailand." Southeast Asian Geotechnical Society, 1991

Lateral resistance of pile groups under seismic excitation is difficult to estimate because of complex interactions of many parameters. Medium scale model tests in sandy ground were carried out to examine effects of pile arrangement, pile number, pile rigidity, and pile spacing on pile group efficiency and load distribution ratio. These factors were further examined in large scale model tests in a soil chamber. Pile interaction parameters for pairs of piles were examined in small scale model tests. Results are compared to those of the PIGLET finite element simulation (Randolph, 1981). 934341 Foundations for a seven-ton forging hammer Kumar, K; Ranjan, G; Prakash, S Proc Ninth Asian Regional Conference on Soil Mechanics and Foundation Engineering, Bangkok, 9-13 December 1991 V1, P233-236. Publ Thailand." Southeast Asian Geotechnical Society, 1991 Foundation design for a forge hammer at a site of weak saturated silts and clays of low compressibility is discussed. To estimate dynamic properties of the soils, field block resonance, free vibration, wave propagation, and cyclic plate bearing tests were carried out. The value of coefficient of compressibility obtained appeared to depend on strain level. Foundations based on conventional reinforced concrete piles were considered too expensive and an alternative of a raft on a sand layer over granular piles was adopted. This has operated satisfactorily for the past 6 years. 934342 Simple pile loading test (SPLT) technique - the principle and applications Lee, M W; Lee, W J; Paik, S W; Yoon, S J Proc Ninth Asian Regional Conference on Soil Mechanics and Foundation Engineering, Bangkok, 9-13 December 1991 V I, P243-246. Publ Thailand," Southeast Asian Geotechnical Society, 1991

Full scale load tests on piles are expensive and time consuming. An alternative, the SPLT, is proposed in which skin friction is employed as the reaction force required to cause pile settlement through usage of a separate pile tip and pile body. The kentledge or reaction piles normally used are not

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