Technical Manual

Inc.

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APPENDIX 3D

MODEL SPECIFICATION – HYDRAULICALLY-DRIVEN PUSH PIER SYSTEMS

Chapter 3

Hydraulically-Driven Push Piers

5.5 Model PP400 Push Pier System

5.5.1 Starter and Pier Tube Sections: The central steel shaft of the starter and pier tube sections

are 4.00-inch outer diameter by 0.226-inch nominal wall thickness hollow structural

section in conformance with ASTM A500 Grade B or C with a minimum yield strength

of 50 ksi and a minimum tensile strength of 62 ksi. The starter tube includes a 1.00-inch

long factory-welded friction reduction collar welded to one end and is manufactured

from 4.50-inch outer diameter by 0.237-inch nominal wall thickness hollow structural

section conforming to ASTM A53 Grade B, Type E & S with a minimum yield strength of

35 ksi and a minimum tensile strength of 60 ksi. The starter shaft and pier tube shafts

are either plain steel or hot-dip galvanized in accordance with ASTM A123.

5.5.2 Shaft Coupling Material: The pier tube shaft coupling material is factory plug-welded to

the pier tube sections and consists of 3.50-inch outer diameter by 0.216-inch nominal

wall thickness hollow structural section in conformance with ASTM A500 Grade B with

a minimum yield strength of 42 ksi and a minimum tensile strength of 58 ksi. The pier

tube shaft coupling finish is plain steel.

5.5.3 Bracket: Retrofit bracket FS400BV is suitable for use with the PP400 push pier system.

The bracket finish is either plain steel or hot-dip galvanized in accordance with ASTM

A123. Bracket hardware finishes are zinc coated in accordance with ASTM B633.

DESIGN AND PERFORMANCE REQUIREMENTS

6.1 Push piers shall be designed to support the nominal compressive load(s) as shown on the

project Plans.

6.2 All structural steel pier components shall be designed within the limits provided by the American

Institute of Steel Construction (AISC) Specification for Structural Steel Buildings (AISC-360).

Either Allowable Stress Design (ASD) or Load and Resistance Factor Design (LRFD) are

acceptable methods of analysis. Bracket testing in accordance with ICC-ES Acceptance Criteria

358 and/or Acceptance Criteria 406 may be considered as an acceptable means of establishing

system capacities.

6.3 Except where noted otherwise on the project Plans, all piers shall be installed to provide an

ultimate pier capacity based on an ASD or LRFD analysis. For ASD, a minimum factor of safety

of 1.5 applied to the service or nominal loading shall be required. Higher ASD factors of safety

may be required based on the project Plans or at the direction of the Owner. When an LRFD

analysis is required, the Owner shall provide applicable pier design information including but not

limited to; factored loads, resistance factors and/or the required ultimate pier capacity.

6.4 The required ultimate pier capacity shall be verified at each pier location by monitoring and

recording final drive forces using the installation hydraulic pressure and the effective area of the

drive cylinder. The maximum drive force shall not exceed the maximum drive force rating of the

push pier system and installation tooling.

6.5 Except where noted otherwise on the project Plans, each pier shall be designed to meet a

corrosion service life of 50 years in accordance with ICC-ES AC358 and AC406.

6.6 The pier design shall take into account pier buckling potential, soil stratification, and strain

compatibility issues.