Location

Chicago, Illinois

Session Start Date

4-29-2013

Session End Date

5-4-2013

Abstract

Underpinning of a private residence using square-shaft helical Screw-Piles is described. A two story wood frame single-family residence constructed in 1996 in a small subdivision started to experience differential settlement not long after construction. The settlement continued for several years, leading to excessive cracking in the basement walls and floor, severe misalignment of doors and windows and cracking of interior walls. It was discovered that the area of the housing development had previously been used as a commercial sand and gravel pit which had subsequently been used as a local dumping area for miscellaneous refuse and which had then been covered by a layer of sand and gravel. In order to stop additional movement, a series of square-shaft helical Screw-Piles was installed around the perimeter of the structure extending through the fill to the underlying dense sand and gravel. Foundation brackets were attached to the existing concrete footings for transferring load to the Screw-Piles. The site conditions are described and the results of the test borings are presented to show the composition and variability of the underlying materials with focus on the fill. A description of the underpinning work is presented to illustrate successful use of Screw-Piles for underpinning lightly loaded structures.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Seventh Conference

Publisher

Missouri University of Science and Technology

Publication Date

4-29-2013

Document Version

Final Version

Rights

© 2013 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Apr 29th, 12:00 AM May 4th, 12:00 AM

Underpinning a Residential Structure on Uncontrolled Fill With Helical Screw-Piles

Chicago, Illinois

Underpinning of a private residence using square-shaft helical Screw-Piles is described. A two story wood frame single-family residence constructed in 1996 in a small subdivision started to experience differential settlement not long after construction. The settlement continued for several years, leading to excessive cracking in the basement walls and floor, severe misalignment of doors and windows and cracking of interior walls. It was discovered that the area of the housing development had previously been used as a commercial sand and gravel pit which had subsequently been used as a local dumping area for miscellaneous refuse and which had then been covered by a layer of sand and gravel. In order to stop additional movement, a series of square-shaft helical Screw-Piles was installed around the perimeter of the structure extending through the fill to the underlying dense sand and gravel. Foundation brackets were attached to the existing concrete footings for transferring load to the Screw-Piles. The site conditions are described and the results of the test borings are presented to show the composition and variability of the underlying materials with focus on the fill. A description of the underpinning work is presented to illustrate successful use of Screw-Piles for underpinning lightly loaded structures.