Materials performance assessment of protective layer of rubble mound breakwaters, southern coast of Iran

Document Type: marine engineering

Authors

1 Department of Marine Industries, Graduate school of Marine Science and Technology, Science and Research Branch, Islamic Azad University, Tehran, Iran

2 Department of Physical oceanography, Graduate school of Marine Science and Technology, Science and Research Branch, Islamic Azad University, Tehran, Iran

Abstract

This study aims to examine the performance of the rock materials in the protective layer of rubble-mound breakwaters in southern Iran, from Rostami Port in Bushehr Province to Beris Port in Sistan and Baluchestan Province. Field inspections were carried out on a great number of rubble-mound breakwaters built in the Persian Gulf and Oman Sea coastal regions to study the protective layer of these breakwaters under ambient conditions as well as to detect the damage caused by factors affecting the failure of the used materials. Subsequently, samples were taken from these rock materials, the specimens were tested in accordance with various quality assessment criteria, and the results were compared with those obtained from international standard tests. The obtained results showed that in most cases, the physical and chemical properties of the local rock materials did not meet standard requirements. As such, these materials are not recommended for use in the construction of breakwaters. In practice, however, these rocks exhibit an acceptable performance in certain cases depending on the position of each rock group in the structure of the breakwater. For this reason, design, construction, and structural considerations can somehow influence the performance of these rock materials in the respective marine structures.

Keywords


American Society for Testing Materials., (1996). Annual books of ASTM standards, Vol. 04 & 08.

British Standard Institution., (1989). Code of practice for determination of aggegate impact value, Bs 812.

Burcharth, H. F., (1987). The lessons from recent breakwater failures. Aalborg university. Denmark.

CEM., (2005). Coastal Engineering Manual, Part VI, chapter 4. U.S.Army corps of engineering.

CIRIA/CUR., (2000). Manual on The use of rock in coastal and shoreline engineering. Construction industry research and information association, London, CIRIA spec puble 83 CUR report 154.

Clark, A. R., (1988). The use of  Portland Stone Rook Armour in Coastal Protection and Sea Defence works. Quaterly Journal of Engieering Geology, London., 2, 113–136.

Dibb, T. E.; Hughes, D. W.; poole, A. B., (1983). The Identification of Critical Factors Affecting Rock Durability in Marine Environments, Quaterly Journal of Engineering Geology, London., 15, 144-161.

 

      

 

Fig. 4: Igneous rocks sample classification based on CUR (right) and Nikoodel (left) criteria

 

Hosseini, R., (2006), Engineering characteristics of biodegradable rocks used in offshore structures, Master's thesis, Engineering Geology, Tarbiat Modarres University. Iran.

International Society for Rock Mechanics., (1980). Commission on standardization of laboratory and field tests.

Jalali, H., (1990). The importance of the rock durability in the stability of pebble breakwaters, First International Conference on Port Construction and Offshore Structures.

Nasehi, A. R., (1997). Determination of appropriate criteria for the use of rocks in the construction of offshore structures, southeastern Iran (Chabahar), Master’s thesis, Tarbiat Modares University. Iran.

Nikoodel, M. R., (1990). Rock degradation criteria, Master's thesis, Engineering Geology, Tarbiat Modarres University. Iran.

Poole, A. B.; Fookes, P. G.; Dibb, T. E.; Hughes, D. W., (1983). Durability of rock in Breakwaters, Design and Constraction, Thomas Telord, London, pp. 31-41

Wakeling, H. L., (1977). The Design of rubble mound breakwater, Symp. On Design of Rubble Mound Breakwaters- British Hovercraft corp.