Notes on NZ Railway

7/31/2019 Notes on NZ Railway

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Notes on New Zealand Railways Corporation:

101.5.1 Vertical Dead Load

Actual Loads shall be used. These may be based on the following unit weights:

Structural Concrete 25 kN/m3

Structural Steel 77 kN/m3

Ballast 19 kN/m3

Complete Railway Tack Sets 5 kN/m3

Fill (typical only) 17 kN/m3

For ballast containing bridges:

minimum Ballast tray width 3.8 m

Track set weight 5 kN/m

(includes full allowance for weight of rail, rail seatings, rail fastenings and sleepers)

Estimating Dead Load of Steel Spans (see Figure 1)

Vertical Train Load (see Figure 2)

250 kN Axle train Loading: (see Figure 3)

Shear Force. Bending Moment and Pier Reaction Tables

Vertical Impact Loads

For concrete structures:

I = LL and I 60% for culverts

LL + DL I 80% for bridges

For steel structures

I = 75 if L 5 where: I = impact as a pe

I = 30 + 60 - L2

if 5 < L 30 (note: may mo

S 50 L = length of span

I = 30 + 10 - 550 if L > 30 of longer of ad

S L-12 S = transverse spa

Note: Steel impact is limited to 75% between floor

Vertical Derailed Train LoadFor derailed train operating at an eccentricity of 1.5m for the track centerline as shown in Figu

Allowance 50% of normal design impact.

Vertical Footpath Live Load/ Footway Loading

For concrete footpaths 5 kPa

For Foothpaths made out of other materials 4 kPa

Wind Load


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WL shall be specified in the AREMA 2006 Manual

Except:

For wind load on bridge projection 2.2 kN/m

For wind load on bridge projection, 3.3 kN/m

if windward side is open

At 1.8m above rail level as wind on train 4.4 kN/m

Vertical Clearance

The design flood flow period return period shall be taken as 100 years

Vertical clearance fromm super structure

soffit level to design flood level

Longitudinal Train Load 10.5 kN/m

8.5 kN/m over loaded portion of the bri

Sideways Train Loads

as per AREMA Manual 2006 requirements

covers train centrifugal and nosing effects

Sideways Handrail Loading

as per the TNZ:Bridge Manual

Concrete Creep and Shrinkage Effects

as advised in Road Research Bulletin Number 70

Note: NZ concrete creeps and shrinks a lot more than is common elsewhere in the world.

Temperature Allowances

Allowances for stress and movement resulting from variations in the

mean temperature of the structure shall be made as below.

structure temperature (C)

steel 25

concrete 20

Load Factors

a. 1.4D + 2.3(L + I) where:

b. 1.4(D + C + EP + B* + NRF + FL) + 2.3(L + I) D : dead load

c. 1.8(D + L + I + C + EP + B* NRF) L + I : live + impa

d. 1.4(D* + EP + B* + NRF + W) C : centrifugal

e. D + EP + B + NRF + EQ LF : braking or t

f. 1.4(D* + EP + B* + EF) N : nosing or l

g. 1.4(D + L + I + C + N + EP + B* + LF + EF) EP : earth press

h. 1.4(D + L + I + C + N + EP + B* + NRF + W + LF) B : buoyancy

i. 1.4(D + L + I + C + N + EP + B*) NRF : normal rive

j. 1.0(D + L + 0.5 I) (derailed train case) W : wind

k. 1.0(D + S) + 1.2(D + L + I) (after strike) EQ : earthquake

* indicates use an overall load factor of 1 on a load case, FL : footway liv

if this is more severe. EF : extreme flo

coeff of thermal expansion

1.20E-05

1.10E-05

0.6 m


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S : striking loa

DL + LL + Imp + Wind on Train + Wind on Bridge + CF + Nosing + Braking

DL + LL + Imp + Wind on Train + Wind on Bridge + CF + Nosing + Traction

DL + Wind on Bridge(only on tall and light structures)

Note: for pile loads, do not include impact loads

Pier Deflection

Pier deflection under unfactored centrifugal wind and

1:50 rake error sway from live and impact loads

Nosing Forces

See A.R.E.M.A. manual

Handrail loading

Applied horizontally or vertically to

any railing on public bridges

Applied horiz. Or vert. to any railing

at the most critical location on rail bridge

Centrifugal Force = 0.1 x LL

Water Forces

The horizontal force effect of flowing water shall be allowed in the design of the piers

The pressure shall be calculated by:

P = K Vo2

where:P = pressure on projected area (k

Vo = water velocity derived from S

K = 0.7 for square ended pie

0.35 for circular piers

0.25 for piers with round

0.5 on debris

2.2 on spans (overtoppi

Note:

A pressure of 0.5P shall be applied to all trailing piles in a pier.

Steel Structure Design

use A.R.E.A. Manual Chapter 15

Concrete Structure Design

Use NZS 3101 for all aspects of concrete design

A.R.E.A. Maunal Chapter 8

1 kN

span/300

N/m750


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rcentage of live load

dify for low speeds as per AREMA)

(meters) for longitudinal members or length

jacent railbeams for floorbeams

cing (meters) of longitudinal members or distance

eam supports for floorbeams

re 4


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(based on NZ Railways Corporation: ONTRACK)

dge (based on NZ Rail Limited)

t loads

force

raction force

teral loads from vehicles

ure or negative skin friction

r or tidal flow

e load

od forces combined with maximum scour


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d

Pa)

ection 4.1 (m/sec)

rs

d ends

g)

Notes on NZ Railway

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