Selection of contractor for the preparation of a comprehensive report on compliance with the basic requirements for construction and technical control of the "Structural" part and for exercising construction supervision for the object: "Agricultural overpass on road I-6 "Sofia - Burgas" at km 381+968"

The subject of this public procurement is the "Selection of a contractor for the preparation of a comprehensive report on compliance with the basic requirements for construction and technical control of the "Structural" part and for exercising construction supervision during construction for the object: "Agricultural overpass on road I-6 "Sofia - Burgas" at km 381+968". The objective of the public procurement is for the Road Infrastructure Agency to select a contractor (consultant) and conclude a contract with them for the preparation of a comprehensive report on compliance with the basic requirements for construction and technical control of the "Structural" part and for exercising construction supervision during the construction of the object, in order to ensure quality construction of the object in accordance with regulatory requirements and adherence to agreed deadlines. 1. Existing situation: Built in 1973. It is intended for the movement of agricultural machinery. The bridge has three spans (11.00+20.00+11.00)m and a total length of 42.16 m. The width gauge is 6.00m, including a 4.50m roadway and two 0.75m sidewalks. Total width of the superstructure – 6.50 m. The height gauge is 4.65 m. Situationally, the overpass is on a straight section of the road, and elevationally on a convex vertical curve. Following an inspection of the structure, an opinion with ref. No. 33-00-297/14.04.2016 was prepared by IPM. The road surface is asphalt concrete, the sidewalks are paving slabs. Steel railings are installed on the overpass, but OSP is missing. Transverse cracks are observed in the asphalt surface in the area of the expansion joints of the piers, abutments, and bridge approaches. The sidewalk blocks are in relatively good condition. Missing elements of the steel railing are present. The superstructure is reinforced concrete, slab-beam type, "simple beam". The main beams are precast, 3 pcs. per span, of ordinary reinforced concrete, spaced 2.40 m axially, with dimensions: height 140 cm, flange width 40 cm, and web width 24 cm. The road slab is monolithic with a thickness of 16 cm. Transverse beams are 3 pcs. per span / over the supports and in the middle of the span / with a height of 117 cm and a width of 30 cm in the middle and 20 cm over the supports. The fixed bearing is a lead plate, and the movable bearing is tangential, made of steel plates. The most serious damage to the overpass is to the main beams in the middle span of the superstructure, caused by impacts from oversized road vehicles. In the middle third of the end main beams, the following damages have occurred as a result of impacts: - Crumbling, cracks, and damage to the concrete in the lower flange of the beams; - Crumbling, cracks, and damage to the lower part of the web of the end beam - Sofia side; - Broken stirrups in the lower flange of the beams; - Severely deformed and/or broken longitudinal bars of the lower row of the lower flange of the beam; - Damaged connection between the middle transverse beam and the main beams. Damage to the middle main beam - Crumbling concrete cover; - Broken stirrups; - Deformed longitudinal reinforcement bars; - Local crumbling of concrete in the lower flange of the main beam. Local leaks through the road slab. The piers are T-shaped walls with consoles. The abutments are wing-type, with three columns and a cap beam, and parallel cantilevered wings with a length of 300 cm. The foundation of the structure is shallow. The presence of the following has been established: - Areas with reduced or missing concrete cover and exposed reinforcement bars on the piers and abutments. - Damage to slopes, cones - Settlement and leakage of embankment on the slopes at the abutments towards road I-6. *Note: For the information of the participants in this public procurement, the Investment Project (Design Documentation) prepared in the "Technical Project" phase (Annex A) will be attached to the public procurement documentation! 2. The subject of the public procurement includes a description of the procurement activities, in accordance with the Technical Specification for the performance of the consulting service (Annex B), attached to the public procurement documentation.