Reconstruction and restoration of A.S. Pushkin Museum complex
and construction of funds storage at Prechistenka street (Moscow)
A.S. Pushkin Museum is located in the former Khrushchev-Seleznyov Mansion, which was reconstructed and renovated to mark 200th
birth anniversary of the great poet. In the same place the new funds storage was built.
The architectural and layout solutions were developed by Moscow design institute MNIIP for the sites of culture, recreation, sports and healthcare.
As a result of estate reconstruction not only the free space has been developed but also underground space both under renovated old buildings and in the atrium between these buildings where an underground conference hall was built.
Geological composition at construction site was as follows:
1-2 m layer of fill up soil mixed with peat and humus, crushed brick;
13-14 m layer of middle-sized sand with gravel, gruss and crushed stone, silt and clayey sands and graveled sands;
1.5-2 m layer of silt hard-plastic clays ;
1.5-2 m layer of dolomited, porous, cavernous limestone eroded to crushed stone, gruss and dust.
The underlying seam is fine-grained, strength fissured limestone.
Water table deposits are below the foundation slab of funds storage premises.
For the purpose of developing underground space and construction of a conference hall in a pit excavated 3.6 meter deeper than feet of many of the foundations of adjacent old buildings it was required to significantly consolidate the foundations and construct a reliable pit enclosure.
Consolidation of foundations was executed by inclined (with mutually crossing axes under foundation feet) jet-grouted reinforced columns, 60 cm in diameter, located in staggered rows. (DWF-drawing, 43 Kb)
Pit enclosing structure was made of vertical secant similar columns combined at top by in-situ reinforced concrete framing beam.
Soil-cement columns were built up by jet cementation of natural soils by "jet-grouting" technology. (DWF-drawing, 47 Kb)
Due to confined space of reconstruction site and close proximity of other protected buildings in process of funds storage premises construction we used "top-down" technique. After the bearing and enclosing walls of bored-secant piles were constructed as well as intermediate bored columns and slab at surface level, two out of five superstructure and three underground floors of the building were built at a time. Limited number of simultaneously constructed floors aboveground was due to that lift shafts and stairwells of building central core were constructed after completion of foundation slab concreting only.
The funds storage "zero cycle" was completely made as cast-in-situ reinforced concrete. Its structure was inseparably linked with construction technology. Originally it was planned to apply classic "top-down" method providing for stage-by-stage construction of underground floor slabs as the pit was deepened. The corresponding design documentation was issued by our company. But for the financial reasons a too heavy time gap occurred and in order to catch up with construction schedule a sort of solutions was to be found.
Considering dimensions of "zero cycle" and vivid spatial nature of its structures functioning such solution did not take much time to find. The core essence of the modified design became excavation pit 11 m-deep protected by only one floor slab at surface level without any additional temporary support of walls of bored-secant piles made by then according to previous design solution physically. (DWF-drawing, 59 Kb, 61 Kb, 53 Kb, 45 Kb, 31 Kb, 30 Kb, 31 Kb, 31 Kb, 28 Kb)
The only thing left was to confirm safe character of this solution implementation by complex computer calculations.
It was to be considered that the walls were made of bored-secant piles where every second pile was not reinforced. Moreover no piles had any rigid constraints in between and the in-situ reinforced concrete slab, 300 mm thick, that united by means of framing beams their caps, was not a flat slab. There have been made a lot of openings and holes in the slab with average reinforcement equal to 92 kg/m3.
Computer calculations based on united spatial scheme with respect to the changing of structures stressed-deformed condition in progress of their construction have demonstrated much less extreme stress values in already made bored-secant pile walls compared to similar calculations on plane models which initiated solution of walls reinforcement using 53 kg/m3 of rebars.
A vivid example of spatial character of "zero cycle" structures work in the funds storage building have become stress isofields in the walls and floor slab at surface level, which we artificially segregated for better demonstration.
These calculations were the only remedy for the general contractor who was on the verge of nervous break-down having seen the changed documentation. With the aim of increasing safety of continuing works under the floor slab above which superstructure floors were built, central bored columns right under the floor slab were braced by temporary diagonal metal rigidity beams.