ITEM
502 STRUCTUREs for maintaining traffic
502.01
Description
502.02 Design
and Construction
502.03
Maintenance
502.04 Removal
502.05 Basis of
Payment
502.01 Description. This work consists of
preparing plans, providing, maintaining, and subsequently removing temporary
structures.
502.02 Design and Construction. As a
minimum, design the temporary structure for a 5-year flood or with
75 percent of the effective waterway opening of the proposed
structure. The Contractor is responsible for any damages caused by
upstream flooding due to insufficient temporary structure size or the
accumulation of debris or sediment in the channel. Provide a clear
roadway width of at least 23 feet (7.0 m) measured from face to face of
guardrails. If the existing structure or approaches or both have sidewalks
provide at least one sidewalk at least 5 feet (1.2 m) wide with adequate
connections to existing walks and in compliance with accessibility standards.
Design
the temporary structure according to the AASHTO LRFD Bridge Design
Specifications except that the design live loading, HL-93 may be reduced by
25 percent.
Submit
working drawings in accordance with 501.05.
Drive piling to
sufficient penetration to carry the superimposed loads according to Item 507, but not less than 24 tons (24 metric tons) per
pile. Perform dynamic load testing to determine required blow count if
piles are not driven to rock.
If the plans
state that the existing superstructure may be used instead of new construction,
do not alter it to meet either the above width or strength requirements.
Instead, move or dismantle and re-erect with sufficient care to avoid any
reduction of capacity. If the superstructure has been restricted by
posting to loads less than permitted by statute, move the posting signs to the
temporary road, unless the superstructure is strengthened to a legal load
capacity. If planning to use the existing superstructure on the temporary
road, notify the Engineer at least 3 days before the superstructure is moved to
allow the Department to establish a detour. Complete the bridge within 48
hours after traffic has been routed over the detour.
502.03 Maintenance. Maintain all portions of
the temporary structure in good condition with respect to both safety and
smoothness for travel as long as it is needed for maintenance of traffic.
Satisfactorily maintain the channel and waterway opening.
502.04 Removal. If the temporary structure is no
longer needed, take ownership and remove it from the site according to Item 202.
502.05 Basis of Payment. Payment
is full compensation for erection, maintenance, performing dynamic load
testing, and subsequent removal of temporary structures.
The Department
will pay for accepted quantities at the contract price as follows:
Item
Unit
Description
502
Lump
Sum
Structure for Maintaining Traffic