Location

Arlington, Virginia

Session Start Date

8-11-2008

Session End Date

8-16-2008

Abstract

The TV tower in Rousse city is the highest in the Balkan area with its 198 m height. It is built up on loess with thickness of the collapsible zone about 15-16 m. The collapsibility has been overcome by excavation deepening up to 14.50 m, dynamic compaction of the excavation bottom with 7.0 tons tamper and building of a 4.5 m soil-cement cushion. A comparison between the calculated and measured settlement and of the soil base moisture content before and after TV tower construction is presented. Geodetic measurements have been made during and after the tower construction. Several calculation methods were used for settlement prediction: Soviet building code for large-size foundations and restricted active zone, the corrected Burmister formula, the method of Kushner and the finite element method. For the load of 146 kPa of the tower, the total settlement in 2005 reached 5.75 cm. The calculated settlement using the finite element method is 6.85 cm, and according to Burmister – 6.75 cm. After 10 years of operation of the tower, increased water content was established in the backfill around it and some increasing of the facility settlement. The next measures were applied: drying of the backfill with quicklime columns, injection of cement-sand mortar in the cavities under the concrete sidewalk, repair of the water & sewerage installations, performance of new vertical planning.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Sixth Conference

Publisher

Missouri University of Science and Technology

Publication Date

8-11-2008

Document Version

Final Version

Rights

© 2008 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Aug 11th, 12:00 AM Aug 16th, 12:00 AM

Foundation Work of High TV Tower in Collapsible Loess

Arlington, Virginia

The TV tower in Rousse city is the highest in the Balkan area with its 198 m height. It is built up on loess with thickness of the collapsible zone about 15-16 m. The collapsibility has been overcome by excavation deepening up to 14.50 m, dynamic compaction of the excavation bottom with 7.0 tons tamper and building of a 4.5 m soil-cement cushion. A comparison between the calculated and measured settlement and of the soil base moisture content before and after TV tower construction is presented. Geodetic measurements have been made during and after the tower construction. Several calculation methods were used for settlement prediction: Soviet building code for large-size foundations and restricted active zone, the corrected Burmister formula, the method of Kushner and the finite element method. For the load of 146 kPa of the tower, the total settlement in 2005 reached 5.75 cm. The calculated settlement using the finite element method is 6.85 cm, and according to Burmister – 6.75 cm. After 10 years of operation of the tower, increased water content was established in the backfill around it and some increasing of the facility settlement. The next measures were applied: drying of the backfill with quicklime columns, injection of cement-sand mortar in the cavities under the concrete sidewalk, repair of the water & sewerage installations, performance of new vertical planning.