Negative skin friction on piles due to water withdrawal from deep artesian wells | |
| Author | Luu Duc Huan |
| Call Number | AIT Thesis no. ST-93-11 |
| Subject(s) | Subsidences (Earth movements) Piling (Civil engineering) |
| Note | A thesis submitted in partial fulfillment of the requirement of the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | In this study, a finite element scheme is presented for solving the physical problems in the case of multi-layered saturated porous elastic media. The Biot' s theory for quasi-statics of porous isotropic elastic solids is assumed to govern. An infinite element algorithm is developed to model the far field of the half space. A discretization of the whole material domain into finite elements in the near field and infinite elements in the far field is proposed. The shape functions of the infinite elements are derived analytically from simple problems. A singular contraction is employed to map infinite elements into finite elements. Finite element formulation is presented based on the variationally principle. The functional of the whole domain is derived and by equating the first variation of this to zero, the characteristic matrix is obtained. In terms of effective stresses, the problem is decomposed into three systems, namely, (1) a free field subsidence under the point sink, (2) a half space without pile subjected to pile-soil interactive force and (3) a fictitious pile characterized by Young's moduli equal to the difference between the Young's modulus of the real pile and the respective Young's moduli of the soil layers. The total effective stress is obtained by combining the fictitious pile stress of system (3) with the effective vertical normal stress in system (1) due to consolidation and the vertical stress in the extended elastics soil layers of system (2) at the original pile position. The negative skin friction based on the effective stress is determined by the finite difference method. |
| Year | 1993 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Karasudhi, Pisidhi ; |
| Examination Committee(s) | Worsak Kanok-Nukulchai ;Pichai Nimityongskul ; |
| Scholarship Donor(s) | Government of Switzerland; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1993 |