moshkov.name/en

Reconstruction of Lithuanian Museum of Ethnocosmology.
Project Description.

1. DATA ON THE EXISTING BUILDING (INTENDED FOR RECONSTRUCTION)

The technical/working design of the existing Astronomy Pavilion was prepared in 1985 by the "INSTITUTE OF KOLKHOZ STRUCTURAL DESIGN" ("Kolukiu statybos projektavimo institutas" (Vilnius, Lithuania)), project manager eng. Vitkauskas, design team leader eng. Grinkas.
Structures of the existing building comprise two steel towers 33.0 m high, interconnected on top by spatial steel truss structure used as the viewing platform. The elevator is installed in one of the towers (the well is built of lime-sand brick, connected with the tower in two places by steel links for brickwork stability). Another tower houses the telescope column of cast reinforced concrete, about 35.5 m high (plane dimensions 3.9x3.9 m) and steel evacuation staircase. The telescope column and its foundation are separated from all other structures by deformation gap.
Plane dimensions of the towers are 4.50x4.50 m, distance between them 6.80 m. Vertical strips of the towers are made from pipe 219x9, grid structure from pipe 140x8 (steel C235), connection units are made using assembling bolts and welding.
The tower foundations are of box type, cast reinforced concrete, deepened to about 6.50 m from ground surface (bottom thickness 600 mm, plane dimensions 19.80x8.50 m; thickness of box part (foundation walls) 400 mm, height 6.70 m, outside plane dimensions 4.90x16.20 m).



Fig. 1: The existing Astronomic Pavilion



2. PROJECT OBJECTIVES AND KEY SOLUTIONS

Reconstruction of the Astronomic Pavilion building of the Lithuanian Museum of Ethnocosmology includes setting of administration office, new viewing platform, new telescope and additional evacuation staircase.



Fig. 2: General view of the reconstructed tower



Office part of the structure: three-storey upturned irregular frustum to be constructed from cast reinforced concrete (pole foundation, cast reinforced concrete overlaps and walls), connected to the existing towers on all overlap levels (tower calculating length reduced).
In order to ensure rigidity of the existing steel towers, the towers will be covered with reinforced concrete rigidity walls, 250 mm thick.
Ellipsoid viewing platform: spatial structure made of steel shapes.



2.1. Calculating Model

Calculation of the spatial structure was performed in order to determine the main steel and reinforced concrete bearing structures for the technical design.
The method of finite elements was used for static calculations of the structures, using computer program STAAD/Pro 2004 SE.
The analysis included 19 calculating and 19 characteristic impact load variants.
24 swaying forms (12 for each plane) were analysed:



Model (consisting of rod and planar elements), calculated in elastic stage on the first swaying form basis without taking into account the geometric nonlinearity.
Effect of elevator well and staircase on the building rigidity was not taken into account.




Fig. 3: Constituents of c(z) factors and pulsation factors





Fig. 4: First sway forms of the structure


       

       



Fig. 5: General views of the calculating model


Nikolaj Moshkov
Design Team Leader
15 January 2006