Vertical Walls with Concrete Facing Panels
2021
MADURAI - RAMANATHAPURAM SECTION - TAMILNADU - India
NATIONAL HIGHWAYS AUTHORITY OF INDIA (NHAI)
CONSTRUCTION OF RS WALLS FOR APPROACHES OF ROB’S/VUP’S OF NH-49
PARAWEB LAYING AT ACUTE CORNER
PANELS ERECTED DURING CONSTRUCTION
COMPLETE VIEW OF REINFORCED SOIL WALL APPROACH
COMPLETED MACRES WALL IN CURVATURE
TRAIN PASSING UNDER ROAD OVER BRIDGE
Problem
NHAI had awarded the project of four laninig of Madurai to Paramakudi and two laning of Paramakudi to Ramanathapuram (Total stretch of 115 Km) in the state of Tamil nadu in EPC mode to M/s. KNR Constructions Limited. Nine Road Over Bridges (ROB), four Vehicular Under Passes (VUP) and two Pedestrain underpasses (PUP) were to be constructed in this stretch and the approaches of these structures were to be retained. The top soil at the site was cohesive (CI) for the top 2m to 3m and most of the ROB’s are in acute skew angles. In order to avoid extensive foundation improvement schemes and complex closing arrangements near abutments due to acute skew angles, Reinforced Soil (RS) Wall was selected as the solution instead of conventional reinforced concrete wall solution for the approaches of these structures. The cost of the conventional solution was very high and the contractor wanted to have a system that is economical, flexible and simple to construct.
Solution
Reinforced Soil (RS) Wall system (MacRes) with precast concrete panels as fascia and Paraweb as reinforcement was proposed for the above problem due to its economy, flexibility, speed of construction, aesthetic finish and long term performance. T shaped fascia panels with corrugations and Paraweb of strengths varying from 30kN to 100kN were used in the project. The connection between the panels and paraweb was done by cavity connector casted in the panels. Frictional fill with angle of internal friction of 32 degrees was used as reinforced & retained fill. The maximum height of the RS Wall is 14.4m. As the top soil of insitu strata is weak, replacement of existing soil below RS Wall with well compacted granular fill was proposed as a part of ground improvement measures. The insitu soil and replaced soil was seperated by a layer of non woven geotextile. The depth of replacement proposed varies based on the height of RS Wall and the subsoil properties. The maximum depth of replacement proposed in this project is 3.0m. The complexity of this project lies in the seven RoB’s which are in skew ranging between 48 degrees and 27.5 degrees with horizontal in plan. Diamond pattern of paraweb laying was proposed .
Used Products
