Dilatometer testing on Bangkok clay | |
| Author | Rasheed, Tariq |
| Call Number | AIT Thesis no.GT-92-01 |
| Subject(s) | Strains and stresses Clay--Thailand--Bangkok--Testing |
| Note | A thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. GT-92-01 |
| Abstract | Versatility, cost effectiveness and time constraints are some of the factors which have attracted the attention of geotechnical engineers towards the use of in-situ methods for estimation of soil properties. No single existing test combines simplicity, accuracy, reliability and low cost to the degree that it can be considered generally applicable and useful for routine geotechnical investigations in all soil types and field conditions. The dilatometer test is quite simple, rapid and low cost and it provides estimation of various soil properties such as stress history, undrained shear strength along with an estimation of the coefficient of lateral earth pressure at rest, Ko . In this research the standard dilatometer equipment was modified to evaluate the potential of the equipment in estimating the stress-strain response of in-situ soils and to investigate the validity of existing correlations in Bangkok subsoils. The modifications include the introduction of electrical displacement and pressure transducers to measure displacement and pressure continuously during the test. The introduction of multimeters made it possible to constantly watch and record the test data. A new dilatometer testing procedure was introduced which records continuous soil displacement against constant pressure increments. In-situ tests were conducted at two test sites in the AIT campus and continuous soil pressure versus displacement relationships were obtained at each test depth. Test data was used to identify the penetrated soil, stress history, coefficient of earth pressure at rest, undrained shear strength and soil stiffness. Results are compared with conventional laboratory and field methods e.g., oedometer tests, triaxial CKCKoU compression and extension tests, field vane and pressuremeter tests. The penetrated soil can be reasonably identified using dilatometer Material Index and Dilatometer Modulus. The stress history estimated from MAYNE correlation is equitable with oedometer test results. The coefficient of earth pressure at rest estimated by LACASSE and LUNNE correlation is a close approximation to laboratory determined K0 values from CK0U triaxial tests. The undrained shear strength values deduced from the dilatometer are equitable to the Cu values estimated from triaxial CK0U test using the SHANSEP technique and by using the normalized undrained shear strength value of 0.29 results are in fair agreement with field vane test. Dilatometer gives the disturbed soil modulus and it is found that with a factor of 5 to 8, the dilatometer modulus is equitable to E50 estimated from the triaxial CKoUE test. |
| Year | 1993 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. GT-92-01 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical and Transportation Engineering (GT) |
| Chairperson(s) | Tian Ho Seah;Balasubramaniam, A.S.; |
| Examination Committee(s) | Bergado, Dennes T.; |
| Scholarship Donor(s) | Government of Norway; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1993 |