Embedded Suction Anchors for Mooring of a Floating Breakwater

Author(s):  
D. J. Kwag ◽  
I. H. Cho ◽  
S. Bang ◽  
Y. Cho

A floating breakwater was built in Southern Korea. Four separate floating breakwater units were moored to ten deeply buried embedded suction anchors. The embedded suction anchor is a type of permanent offshore foundation installed by a suction pile. The cross section of the embedded suction anchor is circular, with its diameter being equal to that of the suction pile that is used to drive it into the seafloor. Vertical flanges are typically added along the circumference to increase its resistance. Determination of the loading capacity and the dimensions of embedded suction anchors are described. Details of the construction and installation of embedded suction anchors, as well as the field proof test results are also discussed. A total of ten steel embedded suction anchors were manufactured and installed successfully. Installation of embedded suction anchors was accomplished with a suction pile attached to its top. Subsequent proof tests validated the design loading capacity of embedded suction anchors. A floating breakwater consisted of four separate units was constructed. Initially, embedded deadweight concrete blocks were considered to moor the floating breakwater units. Later, however, embedded suction anchors replaced the concrete block anchors due to numerous environmental constraints. Each floating unit was anchored with four embedded suction anchors. Field proof tests indicate that the embedded suction anchors can provide necessary resistance against the anticipated wind and wave forces.

2011 ◽  
Vol 38 (3) ◽  
pp. 338-349 ◽  
Author(s):  
António T. Relvas ◽  
António N. Pinheiro

The use of wedge-shaped concrete block overlays to protect embankments subject to flows with relatively high velocities is an idea dating from the late 1960s. Subsequent studies addressed the block stability and design, with or without drainage layer underneath, and the flow characteristics. One aspect still lacking systematic research is the block stability considering the influence of the drainage layer and of the uplift pressure beneath the blocks. The stability of blocks located in the training walls of a trapezoidal cross section has never been investigated, although this type of section is expected when installing a concrete block overlay over embankments. The present study addresses this aspect, using a relatively large facility where the blocks are laid on a drainage layer over an embankment artificially saturated, thus intending to simulate a concrete block spillway installed over a compacted homogeneous earth dam. Data collected both in a trapezoidal flume and in a rectangular flume are is analyzed, together with other authors’ data for this type of stepped overlay. The inherent hydrodynamic stability is verified. Experiments with hydraulic jump formation over the blocks at the end of the flume also showed block stability.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2011
Author(s):  
Krzysztof Drozdzol

Chimneys are structures designed to convey exhaust gases from heating devices to the outside of buildings. The materials from which they are made have a great impact on their fire safety, as well as on the safety of the whole building. As current trends in the construction industry are moving towards improving the environmental impact and fire safety, changes to building materials are constantly being introduced. This also applies to the development of chimney technology, as there is still a recognised need for new solutions when it comes to materials used in the production of chimney systems. This article presents the findings of tests carried out on a chimney made from innovative perlite concrete blocks. Four different perlite concrete blocks that differed in bulk densities were analysed. The obtained results were then compared with widely used leca (lightweight expanded clay aggregate) concrete blocks. The test results confirmed high insulation properties of the perlite concrete block, from which the innovative chimney casing was made. The fire safety level was maintained even in high temperatures that occur during soot fire (1000 °C). These properties were retained despite there being no additional insulation of the flue duct. Even though the thermal load decreased the compressive strength of the chimney blocks, they still displayed sufficient average strength of 4.03 MPa. Additionally, the test results confirmed the possibility of recovering heat from the chimney with the efficiency of 23–30%, which constitutes a considerable increase compared to chimneys made from leca concrete blocks.


Author(s):  
Y. S. Kim ◽  
Y. Cho ◽  
S. Bang ◽  
K. D. Jones

As part of a study on the determination of the suction pile vertical pullout loading capacity, five centrifuge model tests have been conducted on a model suction pile embedded in clay. Details of the centrifuge model test procedures and results are described. Variable in the centrifuge model tests includes the point of the mooring line attachment which was varied from the top to the bottom along the side of the model suction pile. The effect of this parameter on the suction pile vertical pullout capacity is described and discussed in detail. Test results indicate that the loading capacity increases, reaches its peak, and then decreases as the loading point moves downward.


2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Seong-Cheol Lee ◽  
Sangmin Park ◽  
Jaeha Lee ◽  
Kyoung-Chan Lee

In recent years, several studies have investigated the sliding slab track for railway bridges. In the design of sliding slab tracks, one of the most important considerations is to evaluate the shear capacity of the lateral supporting concrete blocks in which dowel rebars are embedded. The predictions of the dowel behavior of rebars by existing models are considerably different. Therefore, in this study, the actual dowel behavior of the rebars embedded in a small concrete block was extensively investigated through experiments. Test variables were concrete compressive strength, dowel rebar diameter and yield strength, specimen thickness, and dowel rebar spacing. Existing model predictions were considerably different from test results. The maximum dowel force increased as concrete compressive strength and dowel rebar diameter increased, while it did not increase considerably with other test variables. Unlike in existing models, the shear slip at the maximum dowel force decreased as the dowel rebar diameter increased. Existing models significantly underestimated the maximum dowel force of the dowel rebars with small diameters and overestimated it for the dowel rebars with large diameters. This work can be useful for developing a more rational model to represent the actual dowel behavior of the rebars embedded in small concrete blocks.


Author(s):  
D. J. Kwag ◽  
I. H. Cho ◽  
S. Bang ◽  
Y. Cho

A floating breakwater is currently being built in southern Korea. Four separate floating breakwater units will be moored to ten deeply embedded suction anchors. The embedded suction anchor is permanent offshore foundation installed by a suction pile. The cross-section of the embedded suction anchor is circular with its diameter being the same as that of the suction pile that is used to drive it into the seafloor. Vertical flanges are added along the circumference to increase its resistance. The design, construction, installation, and proof testing of embedded suction anchors are briefly described.


2014 ◽  
Vol 941-944 ◽  
pp. 786-799 ◽  
Author(s):  
G. I. Grinfeld ◽  
Alexsandr S. Gorshkov ◽  
Nikolay I. Vatin

This article deals with the strength and thermophysical test results made on the basis of the masonry samples of cellular autoclave curing concrete (aerated concrete blocks) with the use of polyurethane adhesive. Aerated concrete masonry walling with the use of polyurethane adhesive is indicated herein to be technologically feasible and economically viable. The major advantage of the masonry option under consideration lies in the following aspect: thermal conductivity of polyurethane adhesive used to fasten aerated concrete blocks in masonry walls is significantly less than thermal conductivity of concrete adhesives and mortars. For this reason, thermal insulation properties of the masonry with polyurethane adhesive appear to be better comparatively to the block masonry made with the usage of concrete adhesives of any other type. On the ground of the tests conducted the following was resumed: it is acceptable to carry out masonry works with the use of aerated concrete blocks and polyurethane adhesive in construction of exterior and interior nonbearing walls provided appropriate justifying calculations are made.


Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as


2020 ◽  
Vol 2 (2) ◽  
pp. 08-15
Author(s):  
Rahma Triyana ◽  
Salmi Salmi

Malaria is one of the health problems in Indonesia, especially West Sumatra. Determination of the description of Malaria disease in an area is needed to determine the spread and severity of the disease. This study aims to determine the frequency distribution according to age, sex and place of residence, description of the types of Plasmodium causes of Malaria and hematological features in Malaria patients at Siti Rahmah Padang Hospital in 2018. This type of research is a descriptive observational study with an approach or design cross section (cross sectional). The frequency distribution of Malaria sufferers in Siti Rahmah Padang Hospital in 2018 according to the highest age was in the age group 21-30 years as many as 28 cases (36.8%), the highest sex among men was 46 (60.5%) and the highest number of residences was found in Koto Tangah sub-district there were 31 cases (40.8%). The type of Plasmodium found in Malaria cases in Siti Rahmah Padang Hospital in 2018 was P. vivax (73 cases (96.05%)) and P. falciparum (3 cases (3.95%)). The results of laboratory tests on Hb, hematocrit, platelet and leukocyte levels in Malaria positive patients in Siti Rahmah Padang Hospital in 2018 were in the normal range.


2020 ◽  
Vol 2 (2) ◽  
pp. 08-15
Author(s):  
Rahma Triyana Y ◽  
Salmi Salmi

Malaria is one of the health problems in Indonesia, especially West Sumatra. Determination of the description of Malaria disease in an area is needed to determine the spread and severity of the disease. This study aims to determine the frequency distribution according to age, sex and place of residence, description of the types of Plasmodium causes of Malaria and hematological features in Malaria patients at Siti Rahmah Padang Hospital in 2018. This type of research is a descriptive observational study with an approach or design cross section (cross sectional). The frequency distribution of Malaria sufferers in Siti Rahmah Padang Hospital in 2018 according to the highest age was in the age group 21-30 years as many as 28 cases (36.8%), the highest sex among men was 46 (60.5%) and the highest number of residences was found in Koto Tangah sub-district there were 31 cases (40.8%). The type of Plasmodium found in Malaria cases in Siti Rahmah Padang Hospital in 2018 was P. vivax (73 cases (96.05%)) and P. falciparum (3 cases (3.95%)). The results of laboratory tests on Hb, hematocrit, platelet and leukocyte levels in Malaria positive patients in Siti Rahmah Padang Hospital in 2018 were in the normal range.


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