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Previous experimental tests on clays have confirmed the non-coincidence of principal strain increments with principal stress axes even though the stress rate is colinear with the current stress. To simulate the non-coaxial behavior of saturated clay subjected to monotonic proportional or non-proportional loading with constant principal stress rate directions, an anisotropic hypoplastic model is presented in this paper. The model is proposed by incorporating an improved anisotropic asymptotic state boundary surface (ASBS) and a non-coaxial asymptotic strain rate direction into the original explicit-ASBS hypoplastic model. The non-coaxial flow results from a non-coaxial stress rate defined by a Gram-Schmidt orthogonalization process based on a reference stress tensor. The capability of the proposed model is demonstrated by simulating the test data performed in hollow cylindrical apparatus (HCA) on Wenzhou clay and Shanghai clay with different drainage conditions and initial consolidation states. In addition, a series of numerical stress probing tests have been conducted to gain further insights into the properties of the proposed model. [ABSTRACT FROM AUTHOR]

This paper investigated the installation effects of a driven prestressed high-strength concrete (PHC) nodular pile in deep soft clay through full-scale tests, and the behavior of a driven PHC nodular pile is analyzed based on the field test results. The test results demonstrated that the driven PHC nodular pile installation process induced significant disturbance in the surrounding soil. The excess pore water pressures (Δu) that were induced by the installation of a driven PHC nodular pile were larger than the Δu that were induced by the installation of a driven PHC pipe pile. The driven PHC nodular pile installation caused significant Δu in the soil down to 2 m below the pile base, and the Δu became much smaller in the soil at 4 m below the pile base. The Δu dissipated slowly in the soft clay layers, and the Δu in the surficial soil layers dissipated faster than that in the deep soil layers. The nodules along the PHC nodular pile shaft could increase the pile shaft capacity. The measured shaft resistances of 350(400)-mm PHC nodular piles were 1.17–1.18 times the calculated shaft resistances of 350-mm PHC pipe piles in soft clay layers. [ABSTRACT FROM AUTHOR]

Building damage induced by the excavation conducted for the three-storey basement of the Kerry Center – a modernised business centre comprising large-scale departmental stores, business offices, apartments and a hotel in Hangzhou, China – was investigated. A method for estimating the building damage level considering the spatial effects of soil deformation around the excavation was also developed. The excavation site is in the Hangzhou urban centre, near to which stands an ancient building known as the Red House. Settlement, horizontal displacement and cracks on the Red House were studied to estimate the actual damage level. Surface settlements around several excavations were analysed to obtain a surface profile along the excavation. The results showed that the profile could be simplified to a parabolic model. A damage criterion based on the average state of strain in the distorted portion of the structure was derived considering the spatial effects of soil deformation. Different damage criteria, including tensile stress, cracks, distortion and horizontal strain, were used to evaluate the damage level of the Red House. The result obtained from the damage criterion presented in this paper agrees well with the actual building damage level. This criterion formed the basis of the preliminary analysis conducted prior to finite-element modelling. [ABSTRACT FROM AUTHOR]