| Author | Vu Anh Khoa |
| Call Number | AIT Thesis no. WM-95-10 |
| Subject(s) | Capes (Coasts)
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. WM-95-10 |
| Abstract | When predominant swell waves obliquely arnve to a sandy coast containing headlands, the shoreline will be sculptured, its planform approaches a distinct shape while beach profile also reaches a stable formation which appears to be in equilibrium .. At equilibrium, the net sediment transport rate in the bay decreases and eventual ceases. A series of model beach studies is carried out to investigate the planform of bayed beaches in static equilibrium (no sediment supply from the upcoast area is allowed). The experiments are set up for small approaching angles to the shoreline. The small wave angles are limited not to exceed 30° which has few available laboratory data. Five oblique angles of approaching waves 0°, 10°, 20°, 25° and 30° are used in the tests while other model parameters maintained unchanged. Shoreline at the still water level is measured every 2-hour interval until the stable shoreline is obtained. Comparisons on various aspects of bay characteristics between observed model tests with existing theories are conducted, which is found that for the incident angles of waves greater or equal to 25°, the shoreline indentation predicted by existing theoretical equations are underestimated and vice versa for the angles of 20° and 1 o0 . In case where breakwaters are used as headlands allowing diffraction to occur at both end sections of the bay, the models also show that the tip of downcoast breakwater could not be used as control point or bay extremity in predicting the stable shoreline using the existing theories and that careful prediction the control points must be carried out before the equilibrium shoreline could be drawn. The study suggests that for the wave angles y greater or equal to 25° the downcoast control point should be defined as the intersection point of the wave orthogonal passing the tip of downcoast headland and the shoreline where the tangent is parallel to wave crests whilst for y less than 25° it may be located at the inner tip of downcoast breakwater. The upcoast control point would be positioned at the inner tip of upcoast breakwater where diffraction takes place. By this method of defining downcoast control point, the present experimental shoreline is found to be better agreement with the predicted equilibrium bayed shape. Comparison on HSU' s parameters also indicates that when the approach angle increases the experimental values of the coefficients would converge to their theoretical values. |
| Year | 1995 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. WM-95-10 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Sutat Weesakul; |
| Examination Committee(s) | Suphat Vongvisessomjai;Kyotoh, Harumichi; |
| Scholarship Donor(s) | Government of Japan; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1995 |