1993-10-08_REVISION - C1981017

• Permit No: C1981017
• IBM Index Class Name: Revision
• Doc Date: 10/8/1993
• Doc Name: Bid Documents ‎(IMP)‎ Revision MR-45
• Type & Sequence: MR45
• Media Type: D
• Archive: No

Concrete Pillar Support Design
The pipe and existing trough will be supported by a 3 ' diameter
reinforced concrete pillar using a 3'CMP as the form. The pillar
will be installed immediately behind the existing flume. Number 7
reinforcing bar is used throughout the 3' pillar . The pillar will
rest on a reinforced concrete bearing pad of 6 ' x 6 ' x 2 ' thickness .
The bearing pad is reinforced with 2 re-bar mats , one located 4
inches below the pad ' s top surface and the other located 4 inches
above the bottom surface. Re-bar in the pad wi 11 form a rectangular
grid on 6 inch centers . The re-bar configuration and the detail of
the joining of the pad to the column are shown on Drawings 2 and 3.
All re-bar will be 7/8 inch diameter steel . The poured concrete
column is anchored to the bearing pad using radially bent anchor
bar emrging from the lower mat and extending into the column for a
distance of 4 feet. The anchor bar in the column will extend
radially to the peripheral edge of the lower mat in the bearing
pad. The re-bar in the column itself will be in a circular pattern
located 4 inches from the outside edge of the column on 6 inch
centers .
Four , 1" diameter anchor bolts , extending for 24" into the column
from its upper edge, will protrude 4" making a rectangular grid 12"
x 18" in size. The rectangular major axis is oriented at right
angles to the direction of flow in the pipe. A transvers 12" 1
beam, supporting the concrete flume and the pipe will be anchored
to the concrete column using the 1" bolts . Drawing 4 shows an
isometric view of the pillar , pipe, apron and trough .
The concrete pillar and beam is more than adequate to handle the
weight of the concrete flume, the 9 ' steel pipe and the weight of
a debris flow for a 100 year event with an acceptable safety
factor .
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