Bangkok Clay Research Articles

Full scale load test of granular piles with different densities and different proportions of gravel and sand on soft Bangkok clay. Technical note : Bergado, D T; Lam, F L Soils FoundV27, N1, March 1987, P86–93

Full scale load test of granular piles with different densities and different proportions of gravel and sand on soft Bangkok clay. Technical note : Bergado, D T; Lam, F L Soils FoundV27, N1, March 1987, P86–93

Undrained Deformability and Strength Characteristics of Soft Bangkok Clay By the Screw Plate Test

Abstract Eighteen screw plate tests were carried out using 10-in. 25.4-cm diameter plate, and three types of laboratory test were performed, namely, 18 unconfined tests, 31 unconsolidated-undrained triaxial tests, and 18 one-dimensional consolidation tests. The sampling and testing were carried out at three sites inside the campus of the Asian Institute of Technology in the soft clay layer. At each site, six screw plate tests were performed at depths of 2.50, 4.50, and 6.00 m, and three boreholes were made to take 60-cm-long Shelby tube samples at the test levels. The screw plate test results were calibrated with unconsolidated-undrained (UU) triaxial test results and the bearing capacity factor Nc was found to be 11.00 while the undrained modulus factor K was found to be 0.61. The screw plate test results were also correlated with the unconfined compression (UC) test and one-dimensional consolidation test in this study as well as with the vane shear test and pressuremeter test results from previous investigations. Furthermore, the pressuremeter-settlement-time relationship was evaluated, and it was found that the logarithm of settlement rate, log s, decreased linearly with the logarithm of time, log t, and increased linearly with the logarithm of the stress level, log P′.

Full Scale Load Test of Granular Piles with Different Densities and Different Proportions of Gravel and Sand on Soft Bangkok Clay

The behavior of granular piles with different densities and different proportions of gravel and sand on soft Bangkok clay was investigated. A total of 13 piles were installed with 0. 30 m diameter and 8. 0 m long using a non-displacement cased borehole method with 1. 20 m spacing in a triangular pattern. The piles were grouped into 5 categories. Groups 1, 2, and 3 with 3 piles each, were constructed using sand compacted at 20, 15, and 10 hammer blows per layer, respectively. Group 4 was made of gravel mixed with sand in the proportion on 1:0. 30 by volume and group 5 was constructed with gravel; both groups consisted of two piles each were compacted at 15 blows per layer. Four active and 2 dummy piezometers were installed for monitoring pore pressures. The soil properties were investigated by the field vane and pressuremeter tests. The ultimate capacity of each granular pile was determined by using full scale plate load tests. Using the pressuremeter results and the method by Hughes et al (1975), the predicted ultimate pile capacity and load-settlement curve agreed well with the experimental data. The maximum bulge in the pile was observed to be about one pile diameter from the ground surface. It was found that the pile made of gravel with 15 blows per layer (Group 5) yielded the maximum ultimate pile capacity closely followed by the piles constructed out of sand with 20 blows per layer (Group 1). In an earlier investigation (Bergado et al, 1984), it was found that the ultimate pile bearing capacity was 3 to 4 times greater than that of the untreated ground and that the piles acted independently when the spacing was 3 pile diameters or greater.

Reliability assessment of test embankments on soft Bangkok clay by variance reduction and nearest-neighbor methods

This paper presents the application of probabilistic slope stability model based on variance reduction method on the Nong Ngoo Hao (NNH) test embankment and the probabilistic settlement evaluation of AIT test embankment using the nearest-neighbor method. The NNH embankment was constructed to failure. Sample autocorrelations were obtained from corrected vane shear test data as well as from the Dutch cone test data in both horizontal and vertical directions. The results showed that using a design criteria of probability of failure of 10 −3, a design safety factor of 1.12 is recommended for 3-D analysis. In 2-D analysis, the variance reduction method yielded lower probabilities of failure compared to an earlier work based on Monte Carlo method. For the AIT test embankment, the statistical data for the occurrence of fine sand and silt lenses in the soft Bangkok clay were obtained and the inclusions were probabilistic settlement prediction in conjunction with the method of Skempton and Bjerrum and Lacasse's approximation showed reasonable agreement with the observed values.

Skin friction tests on driven piles in soft Bangkok clay : Brenner, R P. Balasubramaniam, A S Proc 6th Budapest Conference on Soil Mechanics and Foundation Engineering, Budapest, 2–5 October 1984P327–334. Publ Budapest: Akademiai Kiado, 1984

Skin friction tests on driven piles in soft Bangkok clay : Brenner, R P. Balasubramaniam, A S Proc 6th Budapest Conference on Soil Mechanics and Foundation Engineering, Budapest, 2–5 October 1984P327–334. Publ Budapest: Akademiai Kiado, 1984

Geology of the Bangkok Clay

Geology of the Bangkok Clay

Large diameter bored piles in Bangkok clay : Promboon, S; Brenner, R P Proc 10th International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15–19 June 1981, V2, P815–818. Publ Rotterdam: A. A. Balkema, 1981

Large diameter bored piles in Bangkok clay : Promboon, S; Brenner, R P Proc 10th International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15–19 June 1981, V2, P815–818. Publ Rotterdam: A. A. Balkema, 1981

Settlement of a 55 km long highway on soft Bangkok clay : Cox, J B Proc 10th International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15–19 June 1981, V1, P101–104. Publ Rotterdam: A. A. Balkema, 1981

The settlement characteristics of a 55 km long highway on Bangkok clay are described. Total settlements of the highway embankment 10 years after construction have varied from 100 to 240 cms. Construction settlements of 20 to 80 cm were found to conform to settlements estimated from elastic methods using the Settlement Ratio method but closer estimates were obtained by adding the estimated rapid consolidation settlements in the overconsolidated stress range. Post construction settlements of 40 to 110 cm were found to be influenced critically by whether the induced stresses from the embankment loading exceeded the apparent preconsolidation pressure or not. A reasonable correlation between estimated consolidation settlements and actual post construction settlements was obtained except near Bangkok, where large subsidence effects due to ground water lowering have increased embankment settlements.

Yielding of weathered Bangkok clay : Balasubramaniam, A S; Hwang Zue-Ming Soils Found, V20, N2, June 1980, P1–15

Yielding of weathered Bangkok clay : Balasubramaniam, A S; Hwang Zue-Ming Soils Found, V20, N2, June 1980, P1–15

Yielding of Weathered Bangkok Clay

A comprehensive series of triaxial compression tests was carried out on undisturbed samples of Weathered Bangkok Clay. These tests included (i) anisotropic consolidation under different stress ratios (ii) undrained tests and (iii) drained tests. A yield locus for volumetric strain is established for the Weathered Clay which separates the states for which the volumetric strain is small from those for which the volumetric strain is large. The strain paths followed during anisotropic consolidation are made up of two straight lines with different slopes. One corresponds to the case inside the yield locus and the other corresponds to the case outside. (du/de)n vs n relationships are found to be different for both cases. From a series of undrained tests carried out on samples consolidated to pre-shear consolidation pressures less than the maximum past pressure, the effective stress paths in (q, p) plot are found to be approximately parallel to the q -axis and the constant shear strain contours are found to be nearly parallel to the p -axis. The results of undrained and fully drained tests on Weathered Clay consolidated to the normally consolidated states are presented and discussed.

Closure to “Deformation and Strength Characteristics of Soft Bangkok Clay”

Closure to “Deformation and Strength Characteristics of Soft Bangkok Clay”

Discussion of “Deformation and Strength Characteristics of Soft Bangkok Clay”

Discussion of “Deformation and Strength Characteristics of Soft Bangkok Clay”

Deformation and strength characteristics of soft Bangkok clay : Balasubramanian, A S; Chaudhry, A R J Geotech Engng Div ASCE, V104, NGT9, Sept 1978, P1153–1167

Deformation and strength characteristics of soft Bangkok clay : Balasubramanian, A S; Chaudhry, A R J Geotech Engng Div ASCE, V104, NGT9, Sept 1978, P1153–1167

Deformation and Strength Characteristics of Soft Bangkok Clay

A comprehensive series of stress controlled triaxial compression tests was carried out on Soft Bangkok Clay. Undisturbed samples of soft clay were taken from Nong Ngoo Hao, a site situated about 15 km east of the coast in the Chao Phraya Plain. Altogether, four different types of triaxial tests were carried out and these include: (1)Undrained tests with constant cell pressure and with 1-hr and 1-day load increment durations; (2)fully drained tests with constant cell pressure; (3)constant mean normal stress tests under drained conditions; and (4)anisotropic consolidation tests. The experimentally observed stress-strain behavior is compared with the predictions from various stress-strain theories.

Critical state parameters and peak stress envelopes for Bangkok Clays

Summary This paper is concerned with a detailed study of the critical state parameters and peak stress envelopes for undisturbed samples of Bangkok Clays (‘Weathered Clay’, ‘Soft Clay’ and ‘Stiff Clay’) taken from a site called Bangpli which is about 28 km from Bangkok. Both triaxial compression and extension tests were carried out with a wide variety of applied stress paths in a manner similar to that adopted by Parry (1960) . For all types of tests the end points are presented in ( q, p ), ( w , log p ) and ( w , log q ) plots; q is the deviator stress, p is the mean normal effective stress and w is the water content. The Mohr Coulomb strength parameters are also evaluated for each series of tests. The results are discussed in relation to the critical state concept of Roscoe et al. (1958) and the water content-strength relationships of Henkel (1959) .

Discussion: Deformation characteristics of weathered Bangkok Clay in triaxial extension

Discussion: Deformation characteristics of weathered Bangkok Clay in triaxial extension

Deformation characteristics of weathered Bangkok clay in triaxial extension

Deformation characteristics of weathered Bangkok clay in triaxial extension

State boundary surface for weathered and soft Bangkok clay : Balasubramaniam, A S; Chaudhry, A R; Hwang, M Aust Geomech J, VG6, N1, 1976, P43–50

State boundary surface for weathered and soft Bangkok clay : Balasubramaniam, A S; Chaudhry, A R; Hwang, M Aust Geomech J, VG6, N1, 1976, P43–50

Deformation characteristics of weathered Bangkok Clay in triaxial extension

The deformation characteristics of weathered Bangkok Clay is studied in detail by carrying out two series of strain controlled undrained triaxial tests under extension conditions. Undisturbed samples of weathered clay were taken at a depth of 2·5 m to 3 m from Bangpli (Nong Ngoo Hao), a site situated 28 km southeast from Bangkok, Thailand. Both series of tests were carried out on isotropically consolidated samples. However, Series I corresponded to the case wherein the axial stress was reduced while the lateral stress was maintained constant. In the second series of tests, the axial stress was kept constant and the laterial stress was increased. The stress–strain behaviour and strength characteristics from both types are presented and discussed. Les caractéristiques de déformation de I'argile altéeré de Bangkok sont étudiées en détail en effectuant deux séries d'essais triaxiaux non-drainés à déformation imposée dans des conditions d'extension. Des échantillons intacts d'argile ont été prélevés, à une profondeur de 2·5 m à 3 m, à Bangpli (Nong Ngoo Hao), un chantier situé à 28 km au sud-est de Bangkok, Thaïlande. Les deux séries d'essais on été effectuées sur des échantillons consolidés isotropiquements. Cependant, la série I correspond au cas où la tension axiale est réduite pendant que la tension latérale est maintenue constante. Dans la deuxième série d'essais, la tension axiale a été gardée constante et la tension latérale augmentée. Le comportement con-rainte–déformation et les caractéristiques de resistance des deux types d'essais sont présentés et discutés.

Investigation of an embankment failure in soft clay

Reported here are the results of an investigation into the failure of a low road embankment founded in soft Bangkok clay and flanked by retaining walls. A rotational slip appears to have occurred, the factor of safety of the embankment under its own weight being only about 1.2. While traffic loading was certainly a contributory factor, failure was probably caused by the excess pore pressures generated in the soft clay when long concrete piles were driven adjacent to the retaining wall as a remedial measure.