The Intermediate River Bank Protection Technique in Critical Geo-fluvial Conditions Using Jute Rope Grid

This study investigated an effective protection strategy for the intermediate period of the bioprotection technique using the jute rope grid. This paper presents the results and interpretation of the experimental study of a model river bank subjected to failure under sudden drawdown conditions and its response after protection with the jute rope grid under the geo-fluvial condition. The model bank was composed of silty clay soil collected from Parlalpur ferry ghat on the left bank of river Ganga, Malda district, West Bengal, India. In this experimental study model, the model river bank with a slope of 1 V:1.5H was prepared in the laboratory considering a linear scale of 1:25 to simulate a prototype river bank in the upper reach of river Ganga in West Bengal, India. The first series of experiments examined the impacts of maximum flood duration, moisture content, and drawdown on the shifting of failure location at the most damaged section of the river bank. The second series of experiments were performed for the model river bank protected with a jute rope grid of various mesh grid areas. At critical geo-fluvial conditions, the effect of the jute rope grid having different mesh grid sizes was investigated to improve failure location and reduce settlement depth at the most damaged section of the river. This study showed a reduction in the damaged area of the bank from 57.8 to 16.7% and 94.8% reduction of settlement employing the optimum jute mesh grid area of 6.25 cm2.