REINFORCED SOIL WALL FOR BRIDGE APPROACH AND RECONSTRUCTION OF ROB 39A AT GONDAL RAILWAY PORTION, GUJARAT
TECHSTRAP POLYMERIC STRIP
The project scope included reconstruction of ROB in the prime area of Gondal (Gujarat), wherein the alignment of old ROB was in skew. Considering the city congestion and adjoining private lands, alternate alignments were not an option. For the current structure, maximum height of retaining wall was evaluated to be approximately 11m.
With due consideration to limited right of way; minimizing land acquisition; poor ground conditions; economy and speed of construction, the consultant has recommended to adopt reinforced soil structure for the approached of ROB in the current project.
Pursuing the detailed geotechnical investigations and the site conditions, it was decided to adopt the reinforced soil wall with panel facia and TechStrap (Geostrap) as reinforcement compared to other alternatives such as RCC retaining walls / gabion gravity walls etc. Following are some of the advantages of adopting reinforced soil walls with panel facia and techstrap reinforcement:
What is TechStrap Polymeric Strip reinforcement?
TechStrap are geosynthetic straps (polymeric strips/straps with a flat webbing like structure) specifically engineered for the reinforcement of soils and other fills in the construction of reinforced soil or mechanically stabilised earth structures. TechStrap Polymeric strips comprises a core of closely packed and tensioned high tenacity polyester filament yarn tendons encased in a tough and flexible sheath of linear low density polyethylene.
Advantages of TechStrap Polymeric Strip
Proposed typical cross section drawing for variable height is as given below:
Based on height of RS wall and structural fill soil conditions, strength of Polymeric strip and length of reinforcement was designed.
EXCAVATION AND FOUNDATION PREPARATION
FOUNDATION LEVELING PADS
ERECTION OF FIRST COURSE OF PANELS
PLACEMENT AND COMPACTION OF FILL UP TO FIRST LAYER OF TECHSTRAP
INSTALLATION OF FIRST LAYER OF TECHSTRAP REINFORCEMENT
ERECTION OF SUBSEQUENT COURSES OF PANELS, FILLING AND INSTALLING TECHSTRAP REINFORCEMENT
The project was successfully completed in October 2020.