PERFORMANCE ANALYSIS OF TRAIL DIKE AND JACK-JETTY SYSTEMS USING LABORATORY 4 AND FIELD DATA IN SOLANI RIVER

Abstract

Trail Dikes (T.D) are impermeable dikes consisting of an additional structural feature extending downstream from the main dike parallel to channel line and works on the principle of distributing energy of flow over a larger area. Jack jetties are the permeable type of dikes and works by reducing the velocity and accumulating the sediment and debris during floods resulting the formation of a new bank. In order to protect the Solar Power Plant situated near the left bank of Solani River in India from bank erosion in recent years, eight number of trail dikes were constructed. In spite of effective deposition of sediments and land reclaimed downstream of the dikes, the sudden erosion of bank by floods shifted the bank about 30M towards the plant during year 2014. To inhibit further erosion, RCC jack jetty systems were hurriedly installed during floods in front of the plant. Due to absence of design guidelines, the implementation of trail dike system in Solani River was based on literature and past experiences in the field. The laboratory experiments were conducted to develop a design approach for trail dikes to tackle similar problems of stream bank erosion by field engineers. Based on the lab experiments, design approach of trail dikes is developed in terms of parameters like spacing, configuration and submergence ratios. Scouring pattern in the vicinity of such dikes under different submergence ratios was also observed. Experiments to analyse the effectiveness of the joint performance of the trail dike and jack jetty systems in the laboratory were also conducted. However the experiments were conducted with the clear water condition, so the researchers in this field have the future scope to conduct experiments with sediment laden water for fine-tuning the results. Comparisons of the lab study with the field results facilitated the thesis to evolve design approach of trail dike system and analyse the structural performance which can be deployed in cost-effective and environmental-friendly manner.