HomeMy WebLinkAboutCDP 15-42; Corbin House; DRIVEWAY GEOMETRY AND LOADING CALCULATIONS; 2016-04-25April 25, 2016
Kyrenne Chua
City of Carlsbad
1635 Faraday Ave
Carlsbad, CA 92008
BEN LUND
ENGINEERING
RE: Driveway geometry and loading calcs for CDP 15-42-Corbin House
Ms. Chua,
Thank you for the fire truck loading and dimensions provided to me via email:
Based on GVWR of 68,500 lbs
1. GAWRfor:
a. Front steer axle-20000 lbs
b. Drive axle-27000 lbs
c. Trailer (tiller) steer axle-21500 lbs
2. Axle Spacing {distance between axle centers, longitudinal along frame):
a. Front steer axle to drive axle -155"
b. Drive axle to tiller steer axle -305"
3. Tire spacing (distance between tire centerlines, transverse across frame per axle):
a. Front steer axle-84.89"
b. Drive axle (axle has duals or 4 tires) inner duals-59.545"
c. Drive axle outer duals-85.575"
d. Tiller steer axle-82. 74"
For criteria 1) it is suggested that you factor the loads to 75,000 lbs.
Calculations for the loads on the concrete driveway strips:
CHECK SOIL BEARING PRESSURE
Drive axle load controls & factor up to assumed GVWR of 75k
{75}/(68.5} = 1.1
(27k)(1.1) = 29.7k say 30k
One side of axle = (30k)/(2) = 15k
Calculate soil pressure at bottom of 3.0' concrete strip
Distributed load area square (conservative)= (3'}(3'} = 9 SF
Pressure at bottom of concrete strip= (15k}/(9 SF) = 1.67 k/SF < 2k allowable OK
Page 1 of 2
BEN LUND ENGINEERING 27790 GRANITE RIDGE Ro, 92026-(760) 410-8171 -BENRLUND@GMAIL.COM
..
BEN LUND
ENGINEERING
Please find enclosed the "FIRE TRUCK & COMPACT CAR EXHIBIT" that shows the fire truck and compact
car tire geometry in relationship to the proposed concrete driveway strips.
Respectfully,
Benjamin R. Lund, PE, PLS
Principal
Ben Lund Engineering
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BEN LUND ENGINEERING 27790 GRANITE RIDGE RD, 92026-(760) 410-8171 -BENRLUND@GMAIL.COM
..
ARE TRUCK & COMPACT CAR EXHIBIT
FOR
CORBIN RESIDENCE
DC
3.0' .I :-t I.
4.5' 4.5'
9.0'
RRE TRUCK DUAL TIRE DETAIL
,. = 3'
4"/3" PCC/AB
DC
3.0' .I + .I.
4.5' 4.5'
9.0'
COMPACT {~'sMART~) CAR TIRE DETAIL
,. = 3'
APRIL 25, 2016
l85~lrn LUND
ENGINEERING
(t;2016 BEN LUND ENGINEERING-27790 GRANITE RIDGE RO, 92026-(160} ·I!G-8171 -BENRLUNDfJGMAIL.COM