Cavity expansion analysis on cone penetration resistance of sand compaction piles | |
| Author | Nawagamuwa, Udeni P. |
| Call Number | AIT Thesis no. GE-01-09 |
| Subject(s) | Cone Sand Clay soils Clay--Analysis |
| Note | A thesis submitted in partial fulfillment of the requirements for the Degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. GE-01-09 |
| Abstract | Strength parameters of a sand compaction pile are normally checked by standard penetration test (SPT). Empirical equations, which are derived from numerous data obtained from uniform sand, are adopted for evaluating internal friction angle (φ') value of the sand pile. However, constraint conditions of a sand pile in the clay improved with sand column piles (SCPs) are considered to be very different from that in the uniform sand. Due to simplicity, speed, continuous profiling and amenability to theoretical modeling, cone penetration tests (CPT) can be used to evaluate φ' for SCP. In this research study laboratory tests were done with a miniature cone, which consisted of two gauges to measure tip resistance and probe resistance, inserted into a sample of saturated sand in a triaxial set-up. Before inserting the cone the sample was consolidated under different confining pressures such as 50, 100, 200 and 400 kPa and then the cone was penetrated at a constant rate to find out the ultimate cavity expansion pressure and the volume change of the sample. These tests were done with two different relative densities of 60% and 72% Toyoura sand. A theory, based on cavity expansion, was developed for computing the cone penetration resistance of sand. The sand was modeled as an elastic-plastic material with a plastic zone and an elastic zone in the SCP and considering the spring action given by the surrounding clay to transfer the confining stresses to the SCP. This theory was used for analysis of calibration chamber tests, as it takes full account of SCP size and boundary conditions. In addition, a parametric study was done to observe the behavior of SCP for different input parameters. The agreement between Vesic theory and the theory developed using cavity expansion for infinite soil mass was 100%. Some differences were observed in the laboratory test results with respect to the cavity expansion theoretical results. A good linear relationship was observed between the ultimate cavity pressure and the internal friction angle using the developed theory. |
| Year | 2002 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. GE-01-09 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical Engineering (GE) |
| Chairperson(s) | Takemura, Jiro; |
| Examination Committee(s) | Bergado, Dennes T.;Park, Kyung-Ho; |
| Scholarship Donor(s) | The Government of Japan; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2002 |