Abstract

Normally consolidated clays generally have such a strength profile that the undrained strength increases nearly linearly with depth. The current paper describes a method of preparing normally consolidated clay layers of which undrained strength increases linearly with depth. The gradient of the increase of undrained strength which the authors intended to create in clay was in the range between 110 and 240kN/m2/m. Kawasaki clay with plasticity index of 26. 9 was preconsolidated on the lab floor under a small surcharge pressure of either 9.8 or 19.6kN/m2. The preconsolidated clay was then consolidated with some surcharge pressure under a centrifugal acceleration of either 40 or 80 g. The surcharge pressure was applied by introducing equal air pressures into three rubber bags installed on the surface of the clay. The magnitude of the pressure was made equal to the preconsolidation pressure on the lab floor to keep the whole layer in the state of normal consolidation. The degree of consolidation after 24 hour-continuous run of the centrifuge was approximately 90%. The change of pore pressurs during centrifuge consolidation was monitored with 5 to 6 pore pressure transducers embedded in the clay. The variation of pore pressures with time predicted by the one-dimensional consolidation theory compared well with the observations. The post-mortem check of the clay revealed that water contents in the clay increased nearly linearly with depth and agreed also well with the theoretical prediction, showing the advantage of the use of centrifuges in preparing normally consolidated clay layers.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.