Technological and design solutions for a linear facility

The design documentation provides for a major overhaul of the embankment wall. The main solutions for the overhaul include: overhaul of the embankment wall; changing the system of surface drainage from the technical sidewalk along the carriageway of the embankment with a change in the transverse slope of the technical sidewalk towards the carriageway; discharge of surface water into rebuilt storm water wells in the carriageway of the embankment; restoration of the structures of the roadways in the places of work to ensure the impermeability of the embankment wall; reorganization of side stones separating the carriageway from the technical sidewalk; restoration of pavement structures of the sidewalk of the lower tier; repair of the asphalt concrete pavement of the roadway at the work sites and the tiled pavement of the technical pavement; arrangement of flower beds in the area of ​​the staircase. The transverse slopes of the technical sidewalk are taken as 20-60‰, the sidewalk of the lower tier - the coastal sidewalk - 20‰. Longitudinal profiles are close to the existing ones. Pavement structures of the roadway in the places of reconstruction of storm water wells and restoration after work to ensure soil impermeability: hot dense fine-grained asphalt concrete type A, grade I, on viscous bitumen BND 60/90, GOST 9128-2009, - 5,0 cm; asphalt concrete hot dense coarse-grained type A, grade I, on viscous bitumen BND 60/90, GOST 9128-2009, - 6,0 cm; geogrid 40/17; hot porous coarse-grained asphalt concrete, grade I, on viscous bitumen BND 60/90, GOST 9128-2009, - 12,0 cm; crushed granite grade 1000, fraction 40-70, with cleats, GOST 8267-93, 25607-2009 - 22,0 cm; fine sand (content of silt-clay fraction 5%), Kf≥3m/day, GOST 8736-93*, - 30,0 cm (for restoration sites in places of dismantled connections and restoration after work to ensure soil impermeability). Constructions of the restored technical pavement: paving slabs GOST 17608-91*, - 8,0 cm; dry cement-sand mixture GOST 23558-94 - 4,0 cm; crushed granite grade 800, fraction 40-70, with rivets, GOST 8267-93, 25607-2009 - 29,0 cm; over the existing sand bed. Structures of the pavement to be restored on the lower tier - the coastal pavement: hot sandy dense asphalt concrete type G grade II, GOST 9128-2009 - 3,5 cm; hot sandy highly porous asphalt concrete grade I, GOST 9128-2009 - 4,0 cm; crushed granite grade 800, fraction 40-70, with cleats, GOST 8267-93, 25607-2009 - 15,0 cm; fine sand, Kf≥3m/day, GOST 8736-93*, - 30,0 cm. After the work, it is planned to mill the roadway to the full width (in the direction of the Bolsheokhtinsky bridge) with the laying of the top layer of asphalt concrete: hot dense fine-grained asphalt concrete type A, grade I, on viscous bitumen BND 60/90, GOST 9128-2009, - 5,0 cm; Side stones providing for the separation of carriageways, sidewalks - 1GP, 3GP, in sections of pedestrian crossings - GPV. Landscaping provides for the installation of lawns, incl. into a berm with a total area of ​​1455 m2 with the introduction of a layer of vegetative soil 20 cm thick. The working design of this section of the embankment was developed in the period from 1967 to 1978 Construction was carried out in stages between 1970 and 1981. The total length of the overhaul section is 794,7 m. coast protection from wave and ice impacts, erosion prevention; supports the bank slope and perceives the lateral pressure of the soil from vehicles on the carriageway of the embankment and from pedestrians on the sidewalk along the wall; architecturally decorates the river bank and is part of the ensemble of embankments of the historical center of the city. The embankment provides the passage of vehicles along the highway, located at the level of the upper tier, and the passage of pedestrians along the sidewalk at the level of the lower tier. The sidewalk 6,0 m wide is arranged at the level of the top of the cornice of the wall of the lower tier. The pavement of the walkway is asphalt-concrete over sandy backfill. Drainage from the lower tier is carried out through drainage wells located at the wall of the upper tier. The wall of the lower tier is protected by a granite parapet 870 mm high. The carriageway of Sverdlovsk emb. has a width of 20,0 m and is separated from the sidewalk of the lower tier by a technical sidewalk 2,80-6,0 m wide in concrete paving, closer to the street - a lawn of variable width 2,80-21,5 m.

Based on the results of the inspection of the surface and underwater parts of the structure and the assessment of its technical condition, it was established that:

1. The current state of the main load-bearing elements of the embankment wall (reinforced concrete piles and elements of a prefabricated-monolithic grillage) is characterized as satisfactory. Bearing elements of visible damage (cracks, destruction of the protective layer with exposure of reinforcement, traces of leaching and carbonization of concrete) do not have. The exception is prefabricated blocks installed on the facade surfaces of the lower platforms of slopes, where concrete destruction is observed with reinforcement being exposed. These defects are characterized according to the terms of durability by the 3rd category of faults.
2. The current state of the granite cladding of the embankment wall of the upper, lower tiers and slopes is characterized in terms of durability by the 3rd category of faults.
3. The transport and operational condition of the sidewalk of the upper tier of the embankment wall, according to traffic safety conditions, is characterized by category B.
   

 The project documentation for the overhaul of the embankment wall provides for: preservation of the existing planned high-rise solutions for the embankment; changing the existing system of surface drainage from the technical sidewalk with the provision of a transverse slope of the technical sidewalk towards the carriageway; elimination of faults identified during the survey of the embankment. The existing wall of the embankment is designed for the normative temporary load on the collapse prism of 2,0 t/m2. A comparative analysis showed that the impact of a load of 2,0 t/m2 under the conditions of the existing planned-height solution of the embankment wall exceeds the impact of loads A14 and H14, provided for by the current standards.

 Capital repair of the embankment wall includes the following complex of works:

1. Overhaul (restoration) of granite facing of the walls of the lower tier, upper tier and slopes.
2. Measures to ensure the impermeability of the existing wall of the embankment.
   

Granite cladding of the embankment wall in the above-water part needs cleaning and jointing in full. To eliminate this type of defect, the design documentation provides for the following types of work:

1. Removal of contaminants from the front surface.
2. Cleaning the front surface from hard-to-remove contaminants using a washer.
3. Jointing the seams of the embankment wall with a repair compound based on the TsMID-3GSh composition with caulking the seams with tow to a depth of 2,5 cm.
   

Defects in the cladding in the form of loss of granite cladding slabs, cracks and chips were found in areas limited in area, mainly at expansion joints. The design documentation provides for the elimination of damage to the cladding in the area of ​​expansion joints, which is carried out together with the repair of the expansion joints themselves. In case of temperature deformations of the embankment, the repaired expansion joints will allow avoiding the breakdown of the granite cladding in the areas adjacent to the seam. Seam design: vertical sealing - sealing the seam between prefabricated blocks with a polyurethane band and sealing the seam along the front edge of the blocks with NO-68-1 rubber with fastening the blocks to concrete with HUS-HR (Hilti) screw anchors; vertical sealing - sealing the seam between the granite slabs of the hinged cladding with a polyurethane bundle and cutting the seam from the facade with a polyurethane two-component sealing mastic TEKTOR-203 (TU 5772-001-50002263-98) or a two-component polysulfide (thiokol) curing sealant AM-05 with filling the seam to a depth up to 10 mm. The width of the seam is not more than 20 mm. Defects in the hinged granite cladding in the form of small losses and chips are subject to mastication with a composition based on polyester resins. The stones of the cornice and parapet, which have cracks and chips, must be replaced in accordance with the technical specifications.

To repair damaged eyelets, the project documentation provides for the following types of work:

1. Dismantling of granite cladding stones (mounted cladding slabs, massive cornice and parapet stones) in the area of ​​the damaged eye. 
2. Dismantling (cutting) the metal structures of the damaged eye.
3. Installing the metal structures of the newly made eyelet (painting with grade A coal tar varnish in 2 layers) into the drilled hole using Hilti chemical anchor capsules.
4. Installation of hinged granite cladding, cornice and parapet.
   

In the areas of underwater crossings, coastal signal signs "Do not drop anchors" (GOST 26600-98) are installed, which are currently lost. To eliminate existing subsidences and dips behind the wall of the upper tier and to prevent their occurrence subsequently, the project documentation for the overhaul developed measures to ensure the soil impermeability of the embankment wall, including restoring the continuity of the structure of the existing rear pile rows: installing a pile grillage behind the existing structure and the wall of the upper tier of an additional solid pile row of sheet pile Larsen IY 10,0 and 14,0 m long. Immersion of sheet pile - high-frequency vibratory driver. To drain water from an additional continuous pile row, a drainage hole is arranged in every 3rd sheet pile. On top, an additional continuous pile row of sheet piles is combined with a monolithic reinforced concrete. hat beam. The mark of the bottom of the cap beam is taken at the mark of the bottom of the existing grillage slab (+) 1,200 (BS). The thickness of the cap beam is taken equal to the thickness of the grillage slab - 70 cm. Concrete of the cap beam - B25 F200 W6. Expansion joints of 3 layers of Mostoplast are arranged along the length of the capping beam. The width of the seam is not more than 20 mm. The distance between the seams is not more than 30,0 m. (+) 3 (BS), in order to reduce the active pressure of the soil, the existing construction of the embankment provided for the installation of an unloading slab: prefabricated reinforced concrete slabs for crushed stone preparation 01,60 cm thick were laid on the prism of the return filter. reverse installation. Also, the design documentation provides for a device behind the capped bar of a return filter. The design of the return filter: crushed stone dumping fr. 3-95,04 to el. (+) 5 (BS) - the bottom of the preparation for the capping timber; dumping of CGM up to el. (+) 39,60 (BS) - the top of the grillage plate; laying on a leveled surface geosynthetic material Dornit; sand dumping to the bottom of the road structure with layer-by-layer compaction.