Development of static and dynamic equilibrium equations of crenulate-shaped bays | |
| Author | Somruthai Tasaduak |
| Call Number | AIT Diss. no.WM-14-04 |
| Subject(s) | Bays Equilibrium Coast changes |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. WM-14-04 |
| Abstract | A headland- bay beach (HBB) ha s a natural bay shape that can be utilized for coastal defense. Its shape changes dynamically and can reaches stable when sediment is balanced or creased. The present study is conducted for static equilibrium bay (SEB), dynamic equilibrium bay (DEB) and the transient state between SEB and DEB . The methodologies consist of the analysis of the natural stable bays in Thailand and then the laboratory experiments are conducted. The results of both are analyzed for t he C coefficients in the parabolic bay shape equation (PBSE) and a new parameter, SSR, is introduced for DEB explanations. SSR is the ratio between supplied sediment rates from a source that close to the upcoast headland to the potential alongshore sedimen t transport rate s. The stable bays in Thailand are selected and classified into SEB and DEB. The best C coefficients are selected from three approaches; Lease Square (LS), Genetic Algorithms (GA), and Differential Evolution (DE). The C coefficients in the PBSE for the SEB are revised for the bays in Thailand. Our results indicate that the new ly derived C coefficients for SEB are slightly different from the original one. The C coefficients for DEB of Thailand’s bays are also analyzed wit h the same manner and utilized to develop the bay equations together with the results from the experiments. Laboratory experiments were conducted for SEB, DEB and their transient state . The new equations for transient bay shape is proposed. The first one is from straight shoreline to SEB and the second one is from SEB to DEB. The proposed equation for the reaching of SEB are developed in term of an exponential function w ith a new parameter ( k ) which related to only wave obliquity. For the transient from SE B to DEB, the parameter k is kept to be constant, while another new coefficient DY is varied . The DY is related only to the SSR. For equilibrium state, the new equations of C coefficients for DEB in PBSE are proposed to account for the effect of sediment input into bays in term of the sediment supply ratio (SSR). This equation is applicable to determine the bay shape in SEB and DEB with in a wide range of variation of SSR . The new C coefficients for the DEB vary uniformly and systematically, similar to those for the SEB. The other proposed equations for bay shape characteristics, maximum indentation ratio ( ) 0 R a , c ritic al angle ( ) C θ , and r atio of indentation area ( ) 0 A A are also derived in this research . Finally, the examples for the application of DEB are expressed by some selected Thailand ’s bays, then the guidelines for application of the new equations are proposed. |
| Year | 2014 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. WM-14-04 |
| Type | Dissertation |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Babel, Mukand Singh; |
| Examination Committee(s) | Sutat Weesakul ;Clemente, Roberto S. ;Noppadol Phien-Wej; |
| Scholarship Donor(s) | Kasetsart University Bangkok, Thailand ;Royal Thai Government Fellowship; |
| Degree | Thesis (Ph. D.) - Asian Institute of Technology, 2014 |