The Southern Bridge Stage 4 project develops solutions for connecting Riga city with the Ķekava bypass. As part of the construction project, engineers have carried out geotechnical investigations, as well as developed solutions for the reconstruction of Ozolciema Street and 4 structures.
The Road department has developed the road design solutions for the reconstruction of Ozolciema Street from Mālu Street to Valdeķu Street (including the reconstruction of Valdeķu and Mālu Streets) un and the connections to Jāņa Čakstes Avenue and the crossing street.
The Bridge department has designed two road overpasses, two pedestrian tunnels and some sections of noise barriers:
- Valdeķu Street overpass over the main route: two spans (13.2 m+13.2 m) of prestressed reinforced concrete slab with a total width of 19.24 m; taking into account the embedment of the main route in the trench, retaining walls with a total length of approximately 225 m were designed at the approaches to the crossing
- Overpass of the main route over Mālu Street: two spans (24 m + 24 m) reinforced concrete slab, separate structure for each carriageway of the main route, each with a total width of 12.80 m
- Two pedestrian tunnels under the main route: steel vaults on monolithic reinforced concrete walls and foundations; opening width 4.80 m, tunnel length 25.80 m and 39.75 m respectively
- Separate sections of noise barriers with a total length of approximately 535 m.
The Geology department has carried out geotechnical investigations within the project from August 2018 to August 2019. Geotechnical borings were carried out at 115 points between 2 and 30 m depth for the road section, tunnels, overpasses and the high voltage electricity line, for a total length of 1303 m; static probing were carried out at 50 points between 7 and 19 m depth for a total length of 631 m. The drilling operations were carried out using drilling rigs URB-2A2, L&K Bohrtechnik KB-10 and Geomash MBU224. The static probing was carried out using a Geotech 220-4 multi-purpose probing rig (with a pressure capacity of 20 tonnes).
A total of 250 samples were tested for granulometric composition, water content,Atterberg limits, organic content, uniaxial compressive strength and groundwater chemistry by the geotechnical laboratory.