Bulb I

The Bulb I (BI51, BI63 and BI75) is a less commonly used ODOT standard girder for medium to long length span bridges. It utilizes the BT section with the deck blocked in to achieve difficult site requirements such as heavy super elevations and vertical curves. Allows girders to be placed closer together for major skews and difficult on site deck pours. Typical users of the design include:

Washington Department of Transportation (WSDOT), Oregon Department of Transportation (ODOT), Idaho Transportation Department (ITD), Montana Department of Transportation (MTD), Alaska Department of Transportation (ADOT), United States Forest Service (USFS)

Span Length

Section Properties (gross)

Product Name	Depth (in)	Area (in2)	Yb (in4)	Ixx (in4)	Iyy (in4)	PLF @ 165
BI51	51"	566	25.2	191444	16303	650
BI63	63"	638	31.1	327551	16519	733
BI75	75"	710	37.1	509572	16735	815

Product Information

The Bulb I (BI) girder is a standard variation of the Bulb-T girder. Use the BI shape only when it has benefits over a Bulb-T girder. Since the BI girder have a narrower top flange, it requires less concrete build-up than a Bulb-T. Therefore bridges with high super elevations (generally, greater than 7%) may want to consider the BI girder.

Standard Design Options

Forming and Diaphragm Inserts.
Adjust web thickness to accommodate post-tensioning (for spliced girders). For such cases increase the web thickness from 6″ to 7.5″
Cast in inserts or hole for diagraph reinforcing
Cast in inserts for mounting utility brackets
Top flange/web holes for mounting deck forming brackets

3D Viewer

3D Viewer Tools

3D Viewer Functions:
Move, Span, Zoom Assemblies
Isolate Single Components in View
Explode Assembly Single Components
Use Markup to Sketch Details
General Measurements for Concept
Print Views

Need More Info?

We Are Here to Help

Have a question, need a budget or detailed schedule? Knife River sales team is ready to discuss precast solutions for your project. Reach out to our staff below :

Eric Holje

Bridge Estimator

[email protected]

(509) 536-3323

Sam Jewell

Outside Sales Representative

[email protected]

(541) 221-8599

Product Family

See featured product related to Bulb I assemblies

View All Products

AASHTO Girder

Box Beam

Bridge Substructure

Voided-Solid Slabs

Bulb T

Deck Bulb Tee

Tri-Deck

WF Girder

Projects

Commercial

Industrial

Institutional

Residential

Transportation

Privacy Overview

This website uses cookies to improve your experience while you navigate through the website. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may affect your browsing experience.

Necessary

Always Enabled

Necessary cookies are absolutely essential for the website to function properly. These cookies ensure basic functionalities and security features of the website, anonymously.

Cookie	Duration	Description
cookielawinfo-checkbox-advertisement	1 year	Set by the GDPR Cookie Consent plugin, this cookie is used to record the user consent for the cookies in the "Advertisement" category .
cookielawinfo-checkbox-analytics	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
cookielawinfo-checkbox-functional	11 months	The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
cookielawinfo-checkbox-necessary	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
cookielawinfo-checkbox-others	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
cookielawinfo-checkbox-performance	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
CookieLawInfoConsent	1 year	Records the default button state of the corresponding category & the status of CCPA. It works only in coordination with the primary cookie.
JSESSIONID	session	The JSESSIONID cookie is used by New Relic to store a session identifier so that New Relic can monitor session counts for an application.
viewed_cookie_policy	11 months	The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.

Functional

Performance

Analytics

Analytical cookies are used to understand how visitors interact with the website. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc.

Cookie	Duration	Description
_ga	2 years	The _ga cookie, installed by Google Analytics, calculates visitor, session and campaign data and also keeps track of site usage for the site's analytics report. The cookie stores information anonymously and assigns a randomly generated number to recognize unique visitors.
_gat_gtag_UA_207329799_1	1 minute	Set by Google to distinguish users.
_gid	1 day	Installed by Google Analytics, _gid cookie stores information on how visitors use a website, while also creating an analytics report of the website's performance. Some of the data that are collected include the number of visitors, their source, and the pages they visit anonymously.

Others

Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet.

Cookie	Duration	Description
viewer-version-in-cookie	2 days	No description