STRUCTURAL DESIGN OF PIPE CULVERT TO BS EN 1295-1

1. STRUCTURAL DESIGN OF
BURIED PIPELINES UNDER
VARIOUS CONDITIONS OF
Rev.:A
Calculated by:VN
Date:03/2015
STRUCTURAL DESIGN OF CULVERT TO BS EN 1295-1
Note: The following colour key is a guide to using the full calculation page.
INPUT DTATA
COMPUTED OUTPUT
DATA TO BE CHECKED
STANDARD DATA
Assumptions:
1. Categories of structural behavior: "Rigid".
2. The design life of a rigid pipe shall be 120 years.
3. Field Conditions (Lightly trafficked areas) as a live load case. The live loading to be
considered for Trunk Roads and Motorways is 45 units of HB loading: further details are given
in Section 2.6 of the ‘'91Guide’'92 (2). The combined loading on pipes installed under Trunk
Roads and Motorways due to superimposed dead load, HB loading and the equivalent water
load (see Clause 3.2.2(a) ) are listed in Table M of the ‘'91Simplified tables’'92 (3).
References:
1. BS 9295:2010: GUIDE TO THE STRUCTURAL DESIGN OF BURIED PIPELINES
2. BD82/00 - DESIGN OF BURIED RIGID PIPES
3. BS EN 1295-1: STRUCTURAL DESIGN OF BURIED PIPELINES UNDER VARIOUS
CONDITIONS OF LOADING
Notes:
1. The design of a pipeline using rigid pipes involves the selection of an appropriate pipe
strength and bedding combination which is able to sustain the most adverse permanent and
transient loads to which the pipeline will be subjected over its 120 year service life.
Factor of safety for maximum crushing load, Fs
(BS EN 1995-1, cl. B.2.12.1.7):
Fs 1.25:=
Depth of cover to top of pipe: H1 0.6m:=
Pipe wall thickness: t 0.2m:=
Outside diameter of pipe: Bc 1.2m:=
Mean diameter of pipe: D 1m:=
Weigth of soil
(BS EN 1295-1,cl.NA.4.3.1):
γ1 19.6kN m
3-
:=
Projection ratio
(BS EN 1295-1, cl. NA.4.3.3):
p 0.7:=
Settlement deflection
(BS EN 1295-1,table NA.4):
rsd 0.5:=
Page 1 of 6

2. STRUCTURAL DESIGN OF
BURIED PIPELINES UNDER
VARIOUS CONDITIONS OF
Rev.:A
Calculated by:VN
Date:03/2015
Load coefficient for incomplete
projection condition
(BS EN 1295-1, Table NA.2):
Cc
H1
Bc
rsd p 0=if
1.23
H1
Bc






 0.02-






0 rsd p< 0.1if
1.39
H1
Bc






 0.05-






0.1 rsd p< 0.3if
1.50
H1
Bc






 0.07-






0.3 rsd p< 0.5if
1.59
H1
Bc






 0.09-






0.5 rsd p< 0.7if
1.69
H1
Bc






 0.12-






0.7 rsd p< 1if
1.93
H1
Bc






 0.17-






1 rsd p< 2if
2.08
H1
Bc






 0.2-






2 rsd p< 3if
2.19
H1
Bc






 0.21-






3 rsd p< 4if
2.28
H1
Bc






 0.22-






4 rsd p<if
0.68=:=
Soil load in wide trench
(BS EN 1295-1, Eq.(2)):
Wc Cc γ1 Bc
2
 19.192 kN m
1-
=:=
Surcharge pressure
(See figure below - Main roads)
(BS EN 1295-1,Figure NA.6):
Ps 80kN m
2-
:=
Concentrated surcharge pressure
(BS EN 1295-1,NA.4.1.4):
Wcsu Ps Bc 96 kN m
1-
=:=
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3. STRUCTURAL DESIGN OF
BURIED PIPELINES UNDER
VARIOUS CONDITIONS OF
Rev.:A
Calculated by:VN
Date:03/2015
Water load coeffiecient
(BS EN 1295-1,cl.NA.4.1.5):
Cw 0.75:=
γw 9.81kN m
3-
:=
Unit weigth of water:
Equivalent load due to weigth of water in pipe
(BS EN 1295-1,Eq.(6)):
Ww Cw γw π
D t-( )
2
4
 3.698 m kN m
2-
=:=
Total design external load, We
(BS EN 1295-1,cl NA.4.1.6):
We Wc Wcsu+ Ww+ 118.891 m kN m
2-
=:=
SUPPORTING STRENGTH OF RIGID PIPES
Class:
(BS EN 1295-1,Table NA.7): Class "Class A Plain":=
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4. STRUCTURAL DESIGN OF
BURIED PIPELINES UNDER
VARIOUS CONDITIONS OF
Rev.:A
Calculated by:VN
Date:03/2015
Bedding factors:
(BS EN 1295-1,Table NA.7):
Fm 1.1 Class "Class D"=if
1.1 Class "Class N"=if
1.5 Class "Class C"=if
1.5 Class "Class F"=if
1.9 Class "Class B"=if
2.2 Class "Class S"=if
2.6 Class "Class A Plain"=if
3.4 Class "Class A Reinforced"=if
2.6=:=
Factor of safety for rigid pipe material
(BS EN 1295-1,Table NA.5):
Fse 1.60:=
Minimum crushing load, Fn
(BS EN 1916/BS5911-1:2002)
Fn 27kN m
1-
 D 225m=if
36kN m
1-
 D 300mm=if
45kN m
1-
 D 375mm=if
48kN m
1-
 D 400mm=if
54kN m
1-
 D 450mm=if
60kN m
1-
 D 500mm=if
63kN m
1-
 D 525mm=if
72kN m
1-
 D 600mm=if
81kN m
1-
 D 675mm=if
84kN m
1-
 D 700mm=if
90kN m
1-
 D 750mm=if
96kN m
1-
 D 800mm=if
99kN m
1-
 D 825mm=if
108kN m
1-
 D 900mm=if
120kN m
1-
 D 1000mm=if
126kN m
1-
 D 1050mm=if
135kN m
1-
 D 1125mm=if
144kN m
1-
 D 1200mm=if
162kN m
1-
 D 1350mm=if
168kN m
1-
 D 1400mm=if
180kN m
1-
 D 1500mm=if
1-
120 kN m
1-
=:=
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5. STRUCTURAL DESIGN OF
BURIED PIPELINES UNDER
VARIOUS CONDITIONS OF
Rev.:A
Calculated by:VN
Date:03/2015
192kN m
1-
 D 1600mm=if
216kN m
1-
 D 1800mm=if
240kN m
1-
 D 2000mm=if
252kN m
1-
 D 2100mm=if
Safe supporting strength
(BS EN 1295-1,cl. NA.4.2):
Check1 if Fm
We Fse
Fn
 "OK", "NOT OK",






"OK"=:=
Table 1: Types of Bedding
Table 2: Minimum crushing loads (Fn) for strength class 120 units with a circular bore for use
in a trench – BS 5911-1: 2010
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6. STRUCTURAL DESIGN OF
BURIED PIPELINES UNDER
VARIOUS CONDITIONS OF
Rev.:A
Calculated by:VN
Date:03/2015
Page 6 of 6