PORT OF TACOMA - PIER 4 RECONFIGURATION - TACOMA, WA. Falsework & Formwork System for Cast-in-Place Concrete

Project Information:

Year of Completion: 2018

Construction Cost: $141 Million

Client: Manson Construction Company

Owner: The Northwest Seaport Alliance

Services Performed:

♦ Design of Falsework & Formwork System for Cast-in-Place Concrete

Deck, Pile Caps & Pile Bent Caps

♦ Pile Barge Analysis

♦ Design of Dolphin Pile Template

♦ Pier Loading & Substation Founda-tion Evaluation

BITTNER-SHEN CONSULTING ENGINEERS, INC. SPECIALTY ENGINEERING: STRUCTURAL · GEOTECHNICAL · CONTRUCTION · MARINE

921 SW Washington St., Suite 765, Portland, OR 97205

Friction collar support at each pile.

BSCE 2016-17, 01/29/2019

T he Northwest Seaport Alliance has decided to reconfigure Pier 4 on the General Peninsula in order to support larger container cranes and vessels. The original pier was con-structed in 1966 and showed signs of being outdated.

The reconfiguration consisted of demolishing most of the existing Pier 4 and reconstructing the pier to align with an adjacent pier. Doing so created one continuous berth capable of serving two 18,000-TEU container ships.

The majority of the new design for Pier 4 consisted of pre-cast concrete panels that span from bent to bent, forming the main pier deck. Manson Construction Company selected Bittner-Shen Consulting Engineers to design the falsework and formwork sys-tem to construct the cap beams at each pile bent. In order to construct these cap beams over water and without drilling or modifying piles, the falsework system design relied on timber

friction collars at each pile. The flexibility in utilizing timber friction collars allowed them to be installed at various elevations to ac-commodate for variance in beam depth. Glu-lam beams spanned between each friction collar, and traditional stick framing was used to support dead loads due to concrete placement, and live loads for a 3-foot access walkway. Before beginning construction, the friction collars were put through load testing. The load test ensured that the design capacity of a single friction collar was met (32,000 lbs). After construction of the cap beams, all friction collars and timber framing could be removed from underneath.

Along with various construction engineering services, BSCE was also responsible for the design of a falsework system to support a portion of the pier that consisted of a cast-in-place concrete deck. The basis of this design was similar to that of the cap beam false-work system.

Cap beams at pile bent.