Rehabilitation of retaining wall on state road A3, section Trojaci - Farish

摘要

This paper deals with design of rehabilitation measures on collapsed retaining wall located in the area of Farish Village in R.Macedonia. The retaining wall which was constructed in the past in order to support the embankment of the state road A3 (road section Trojaci - Farish) experienced significant cracks followed by cracking of the road pavement and landsliding. The damages which occurred on the road affected one traffic lane which was closed for traffic immediately after landsliding. Several preliminary solutions on wall and road rehabilitation were developed and some of them are presented in this paper. The adopted solution was further developed in detailed design according to which rehabilitation measures were executed. These measures involve demolition of the damaged retaining wall and construction of new retaining wall with pile foundation. The new retaining wall is designed not only as a replacement of the damaged retaining wall but also to regain the ground stability on the site. The reinforced concrete piles (d=800 mm, L=3 m) of newly designed retaining wall were calculated as frictional, raft connected piles in zig-zag pattern with 4 m spacing between the piles in one row. The design also involves a construction of wall steam for retaining of road embankment with maximum height of 5.3 m. Total length of the wall is 63 m. This approach was already used for landslide rehabilitation on other sites and it was proven as an effective method for ground stabilization. The designed rehabilitation measures were accompanied with construction of wall drainage system and rehabilitation of road pavement. In order to anticipate the behavior of the retaining wall, road structure and the ground under different load conditions (geostatic load, earthquake load, traffic load etc.) stress-strain analysis were performed in Plaxis 2D software using finite element method. Structural analysis of the retaining wall was also conducted on 3D model using Radimpex Tower software. The software model in Plaxis was developed according to site survey data and ground profile established upon performed geotechnical field investigations works and laboratory testing. The rehabilitation measures were executed as designed in 4 months period (April - August 2013).