Land subsidence and negative skin friction in piles | |
| Author | Piya Poonsawat |
| Call Number | AIT Thesis no.ST-94-19 |
| 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 Civil Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Land subsidence and negative skin friction in piles, due to water withdrawal from deep artesian wells, are analyzed by discretizing the whole domain into finite elements in the near field and infinite elements in the far field. Shape functions of the finite elements are the same as of conventional finite element but shape functions of the infinite elements are derived analytically from simple problem. A singular contraction is employed to map infinite elements into finite elements. The Biot' s theory for quasi-statics of fully saturated porous isotropic elastic solids is assumed to govern the soil media. Finite element fo1mulation is presented based on variational principle. The functional of the whole domain is derived by equating the first variation of this to zero. The Laplace transf01m of governing conditions are solved numerically first, then the inverse Laplace transform of any solution functions are obtained by collocation method. Subsidence results agree closely with those obtained by others. In term of effective stresses, the problem is decomposed into three simple systems, namely, (1) a free field subsidence of half space subjected to the point sink, (2) a half space subjected to pile-soil interaction force and, (3) a fictitious pile with Young's moduli equal to the difference between Young modulus of the real pile and the respective Young's moduli of the soil layers. The total effective stress is the combination of the effective stress of those three systems. The negative skin friction based on total effective stress is determined by finite difference method |
| Year | 1994 |
| 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) | Pisidhi Karasudhi |
| Examination Committee(s) | Worsak Kanok-Nukulchai ;Pichai Nimityongskul |
| Scholarship Donor(s) | King's Scholarship |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1994 |