Final Paper_IWMI 2009

iesl/pub/guide/01 1 Rehabilitation of the Revetment along Galle Marine Drive T.D.T.Pemasiri and B.Wickramarachc hi Abstract: Galle marine drive is the important highway segment which serves to pass from Colombo to southern part of the c ountry through Galle. It was constructed in early 196 0’s. More than one kilometer long revetment was also constructed to support the Marin Drive. It was functioned as a shield to sea waves. However, after construction of the revetment, coastal process got affected and wide beach was vulnerable to erosion. Successive rehabilitations have been carried out to sustain the revetment by placing rock boulders, but none of those attempts were succeeded as a long term solution. It was severely damaged with the hit of Tsunami in 2004 and thereafter it failed to perform to the requirement. As a part of Tsunami Affected Area Rehabilitation Project (TAARP), rehabilitation and improvements to the revetment was proposed to enhance its performance, together with other holistic approaches for the development of the City of Galle. Keywords: Revetment, Geo-textile, Wave overtopping, Wave transformation 1. Introduction Galle is the capital of Southern Province, situated 116 km away from the City of Colombo. (Figure 1). Galle, by been a coastal city, is highly attracted by both local and foreign tourists due to its distinct physical and social characteristics. Hence improvements for the coastal stretch are extremely important to enhance the city’s protection and its scenic beauty. Figure 1 - Location Map Galle marine drive is a major highway segment which serves to pass from Colombo to southern part of the country through Galle. There is heavy daily traffic on this drive because this is the one and only way to connect west and south of the country along the co ast line. It was constructed in early 1960’s [7]. Before constructing the Marine Drive, the beach stretch was rather wide with having approximately 50 meters width. Marine Drive was constructed along the seaward land strip, with reclaiming the beach area. More than one kilometre long revetment was also constructed to support the Marin Drive. It was functioned as a shield to sea waves. 2. Old Revetment Structure Two Aerial photographs taken in the years of 1956 and 1994 are shown in Figure 2 and Figure 3 respectively. A long and wide beach can be seen in 1956 inside the bay. Two main developments, Commercial Port and Marine Drive, can be identified in 1994 image. However, after construction of the revetment, coastal process got affected and wide beach was Galle Colombo Eng. T.D.T.Pemasiri , C. Eng., MIE(SL), B.Sc. Eng. (Moratuwa), M.Sc. (AIT), Engineering Manager, Lanka Hydraulic Institute Eng.B.Wickramarachchi, B.Sc. Eng. (Moratuwa), Senior Engineer, Research & Design Division, Coast Conservation Department

Final Paper_IWMI 2009

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