scholarly journals A 3-D model for ocean waves over a Columb-damping poroelastic seabed

2004 ◽  
Vol 31 (5-6) ◽  
pp. 561-585
Author(s):  
M. Lin ◽  
D.-S. Jeng
2020 ◽  
Vol 8 (1) ◽  
pp. 1-8
Author(s):  
Maulana Arif

The breakwater construction usually founded in coastal area with many public or company facilities. It is very useful to break the ocean waves so it can not reach the shore line. Furthermore, the breakwater construction is also applied as a barier for a port for ship docked. One of the type of breakwaters is tube column filled with compacted sand reinforced by sheet file and tie beam. This research will discuss about the sheet pile displacement in static and dynamic condition. Plaxis is applied as the main tool to built the 2-D model based on given data from field observation. The input parameter for this model is applied in soil stratigraphy, compacted sand column, sheet pile, tie beam, pseudostatic wave force, sea level and earthquake acceleration. The running of this model divided in three condition. There are static condition, static condition with pseudostatic wave force, and dynamic condition. The results show different displacement between the conditions. The sheet pile displacement in static condition is 3.35 cm at harbor side and 1.91 cm at open sea. The sheet pile displacement in static condition with pseudostatic wave force is 12.14 cm at harbor side and 12.08 cm at open sea. The sheet pile displacement in dynamic condition has 5 cm peak both harbor side and open sea. 


2022 ◽  
Vol 10 (1) ◽  
pp. 73
Author(s):  
Xi Chen ◽  
Qi Zhang ◽  
Xiang Yuan Zheng ◽  
Yu Lei

In this study, a semi-analytical solution to the dynamic responses of a multilayered transversely isotropic poroelastic seabed under combined wave and current loadings is proposed based on the dynamic stiffness matrix method. This solution is first analytically validated with a single-layered and a two-layered isotropic seabed and then verified against previous experimental results. After that, parametric studies are carried out to probe the effects of the soil’s anisotropic characteristics and the effects of ocean waves and currents on the dynamic responses and the maximum liquefaction depth. The results show that the dynamic responses of a transversely isotropic seabed are more sensitive to the ratio of the soil’s vertical Young’s modulus to horizontal Young’s modulus (Ev/Eh) and the ratio of the vertical shear modulus to Ev (Gv/Ev) than to the vertical-to-horizontal ratio of the permeability coefficient (Kv/Kh). A lower degree of quasi-saturation, higher porosity, a shorter wave period, and a following current all result in a greater maximum liquefaction depth. Moreover, it is revealed that the maximum liquefaction depth of a transversely isotropic seabed would be underestimated under the isotropic assumption. Furthermore, unlike the behavior of an isotropic seabed, the transversely isotropic seabed tends to liquefy when fully saturated in nonlinear waves. This result supplements and reinforces the conclusions determined in previous studies. This work affirms that it is necessary for offshore engineering to consider the transversely isotropic characteristics of the seabed for bottom-fixed and subsea offshore structures.


2020 ◽  
Author(s):  
Adib Rifqi Setiawan
Keyword(s):  

Pembelajaran tematik adalah metode pembelajaran yang menekankan pemberian tema khusus pilihan untuk mengajarkan beberapa konsep kurikuler Konsep integrasi beberapa subjek untuk mengajar di sekolah Indonesia, secara umum bukan hal baru dan tidak sukses pada masa lalu. Sebagai tambahan, beberapa orang menanggap pembelajaran tematik adalah satu kesempatan sementara sebagian lain memandang bahwa ini memiliki masalah. Namun, jawaban untuk bagaimana penerapan pembelajaran tematik belum dikaji secara menyeluruh. Riset ini menyusun desain pembelajaran tematik untuk membimbing siswa sekolah dasar dalam memperoleh literasi saintifik, mengggunakan pendekatan R&D model 4-D yang direduksi menjadi 3 tahap yaitu: define, design, dan develop. Luaran riset ini adalah desain pembelajaran tematik untuk membimbing siswa sekolah dasar dalam memperoleh literasi saintifik, yang keabsahan dan keandalan dalam kategori dapat digunakan.


2019 ◽  
Author(s):  
Adib Rifqi Setiawan

It is requisite that each activity is necessary to have a clear purpose as it was designed to be a well applicable plan. Scientific literacy indicates that science has value outside scientific practice is hardly modern idea and reality, although we lose sight of this history. Unfortunately, PISA study at 1999-2015 and several preexist works has shows that common science teachings don’t optimally guide students to achieve scientific literacy. As matter of fact, the answer to how to guide student achieving scientific literacy has not been obtained yet. By proposing this work, I am consider that thematic learning as an alternative method to guide students on achieving scientific literacy. Thematic learning is an educational method of teaching in which emphasis is given on choosing a specific theme for teaching concepts. It is based on integrating various information and use it to demonstrate the topic. Pedagogy of thematic learning is based on its exploration of broad areas in one theme. I don’t deny that the concept of integrating subjects to teach in Indonesian schools, generally is not new and has not been very successful in the past. In addition, some people consider thematic learning as an opportunity while others view it as having problems. The answer, however, to how thematic learning education implementation has not been studied yet comprehensively. Therefore, thematic learning lesson plans is very important to be designed then implemented. This work constructs lesson plan to guide primary education student on achieving scientific literacy, using R&D approach four-D model: define, design, develop, and disseminate. It gained lesson plan completed by student worksheets also assessment tests as well, that validated by experts and practitioners nor reliability counted based exclusively on test.


1994 ◽  
Author(s):  
Mark J. Ablowitz ◽  
James H. Curry ◽  
Joe L. Hammack ◽  
Harvey Segur
Keyword(s):  

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