Study on Dynamic Stability of Single Floating Pier Under Waves

Considering the upper structure restraint effect of the floating bridge, the diffraction effect and radiation effect of linear monochromatic waves, the dynamic response equation of floating pier is derived and the factors affecting the dynamic stability of the floating pier are analyzed in this paper. Based on the theory of potential flow, the calculation domain is divided into the interior region and the exterior region. The wave diffraction and radiation problems are solved by the matched eigenfunction expansion method (MEEM). After obtaining the wave excitation force, additional mass and radiation damping coefficient, considering the restraint effect of the upper structure of the floating bridge, the motion differential equation of the floating pier is established, and the response amplitude operator (RAOs) of the floating pier is obtained. The effects of span, mass and stiffness of upper structure, as well as the draft depth, size and net height of floating pier on dynamic stability of floating pier under wave are analyzed. The results show that the increase in the span of upper structure will significantly increase the peak RAOs of sway and heave, and the increase in stiffness is helpful to reduce the peak RAOs of sway and heave. The increase of the floating pier radius can reduce the heave RAO, and the net height on the water surface of the floating pier increases the heave and roll.

Ecological Index of Fouling Organisms in Different Media In Daruba Morotai Island District

On the port pole is very much found biota attached. The biota is barnacles (Balanus sp). The attachment does not only occur in natural substrates. It may also occur in different means of human interest, such as ships and docks. This research is devoted to macroscopic biofouling, whose attachment is massif on the dock pole. This study aims to determine the species and ecological index of biota fouling in different media in the Daruba Morotai Island Regency. The data retrieval method uses a quadratic with a scale of 20×100 cm2. This study used three media, namely wood media (speedboat wooden pier), iron media (speedboat floating pier), and concrete media (Imam Lastori's main pier). Ecological indices analyzed include abundance, Diversity Index, Uniformity Index, and Dominance Index. The analysis results found the most number of macrobiofouling species in the wood medium (7 species). The largest number of individuals found is Branchidontes sp. (661 individuals). The findings of the study of the maximum macrofouling abundance are found in concrete media with a value of 491. Diversity in all media is classified as medium with a value of H' on wood media 1.22, iron media 1.04, and concrete media 1.34. The uniformity index (E) of all three media indicates the uniformity of broad populations with the maximum E found in concrete media 0.84. The study of dominance in wood media by 0.41, iron media 0.48, and concrete media 0.32 showed that dominance is poor.

A method for construction of an energy-efficient ice floating pier in the Arctic using hardened ice

This paper presents studies on increasing the ice strength using various additives. It is indicated that addition of wood fiber (artificial composition) and vegetable fiber (natural composition - frozen peat) to ice is an energy-efficient method to increase its strength. This enhances the possibilities of using ice during building and construction works in the Arctic. As an example, the authors proposed a floating ice pier design.

A Fundamental Study on the Optimal Design of the Floating Tsunami Protection Wharf: About the Floating Body Length

On the vessels moored at the wharf, the situation such as drifting and wash up on the wharf due to the breaking of the mooring lines is occurred by the tsunami. The authors are clarified for applicability of the proposed floating tsunami protection wharf (FTPW). FTPW is the floating pier for tsunami disaster. The effect of FTPW is most promising as disaster prevention and mitigation measures for the moored vessels. The authors examined large scale FTPW until now. However, when floating body length was longer than a ship breadth, the possibility that disaster prevention performance of FTPW decreased was confirmed. In this study, the examination about the influence that floating body length gives in disaster prevention performance of FTPW is performed using numerical simulation. Therefore, in the range of length of FTPW/breadth of vessel = 1.0 to 8.0, it was confirmed that tsunami protection performance of FTPW was shown enough.