A.B. Chance
a Division of Hubbell Power Systems, Inc.
210 N. Allen Street
Centralia, MO 65240 USA
Tel: (573) 682-8414
Fax: (573) 682-8660
E-mail: hpsliterature@hps.hubbell.com
Web site: http://www.abchance.com

Foundation Repair Anchors

MR-MANUFACTURER

Manufactured by A.B. Chance, an ISO 9001 company, headquartered in Centralia, Missouri. With more than 97 years of earth-anchor research and development experience, A.B. Chance also markets to electric utilities, telecommunications and pipeline industries worldwide.

UA-USES, APPLICATIONS

This foundation-underpinning system transfers structural loads to stable strata beneath problem surface conditions.

Unique advantages also have led to a growing range of other applications for tension and compression loads as high as 200,000 lb. per screw anchor. Predictable holding capacities at economical installed costs match various power-installed screw anchor types and sizes to such permanent and temporary uses as:

Building foundation-repair underpinning, new-foundation reinforcement (including seismic-loading resistance by incorporating tieback anchors), transmission-tower anchors, tiebacks, foundations for refinery equipment, and hold-downs for pipelines.

PP-PRODUCT PRESENTATION

The Chance® Helical Pier Foundation System includes round shafts (3/4" solid steel to 10" diameter pipe) and square shafts (1-3/8" to 2-1/4" solid high-strength steel). Single- or multiple-helix configurations and diameters (typically from 8" to 14") are combined with the shaft sizes to match loads. Special techniques and tools derived through experience and engineering expertise give Chance® screw anchors advantages not easily duplicated:

• True helices penetrate soils with minimal disturbance.

• Round-cornered square shafts and precise helix pitches assure both installation ease and capacities as bearing-plates.

To increase product life in aggressive soils, hot-dip galvanizing to ASTM specifications is normally supplied.

AI-ASSEMBLY, INSTALLATION

The Helical Pier Foundation System alleviates stresses on buildings caused by foundations shifting in such problem soils as expansive and fills. As additional support members, these screw anchors extend bearing plates into stable underlying subsoil. Their small-diameter shafts simply penetrate the problem zone without significant disturbance. This is ideal for underpinning foundations showing signs of failure or to upgrade their capacity for additional bearing requirements.

Installed in sections, Chance® screw anchors can get into low-headroom situations. They install quickly by available contractor power tools. Installing equipment may be a utility truck, caisson drill, backhoe, skid-steer loader or hand-held rotary tool.

Each steel screw anchor attaches to an innovative bracket. The support brackets cradle the existing foundation, permit lifting the structure if needed and lock off the load. Torque required to drive the screw anchor correlates to bearing capacity of strata below and so indicates depth necessary for support of the structural load.

For new construction, the bracket is not needed. Before concrete is poured, the anchors install at intervals between forms for the foundation footing and tie into the re-bar gridwork.

For buildings on sites where soil creeps, screw anchors can be installed both vertically and at an angle opposing the downhill creep.

TS-TECHNICAL SUPPORT

To assist design engineers in applying screw anchors, A.B. Chance provides a complete design package comprising:

• A technical manual presenting the state-of-the-art,

• Interactive personal-computer software program for project designs,

• Listings of prices for anchors available to derive job-cost estimates.

The manual accompanies the software to instruct the engineer in pertinent application aspects through commentary on design theory, testing and installation procedures. It presents examples for on-line experience yet minimizes input requirements and decisions. Otherwise, it duplicates the program A.B. Chance anchor-application engineers employ daily to make project-design recommendations. A series of prompts direct the designer to maintain control over essential design criteria. Simple input needed:

  1. Soil data - involves depths of layers, strength parameters and type;


  2. Anchor description - consists of extension length, installation angle, distance to datum;


  3. Load - magnitude and direction.
Based on a multitude of various projects and soil conditions in our cumulative experience, A.B. Chance supports the following services:

Certified installers

Training and field supervision

Design assistance

Geotechnical engineering guidance for special cases

Inventories of standard and specially designed products to match applications to soils.

See "Foundation Support Specification" screen for specification details.