Surveying Undergraduate Programmes - PowerPoint PPT Presentation

1 / 24
About This Presentation
Title:

Surveying Undergraduate Programmes

Description:

Title: Surveying Undergraduate Programmes Author: Uel User Last modified by: Uel User Created Date: 9/21/2004 11:37:35 PM Document presentation format – PowerPoint PPT presentation

Number of Views:51
Avg rating:3.0/5.0
Slides: 25
Provided by: Uel66
Category:

less

Transcript and Presenter's Notes

Title: Surveying Undergraduate Programmes


1
Transverse schemes for bridge decks. Part 1
Beams
Dr Ana M. Ruiz-Teran
2
Types of transverse schemes for bridge decks
3
Types of transverse schemes for bridge decks
Beam deck
Slab deck
Box girder
4
Type of beams
5
Deck with precast PC I beams
Deck with precast PC U beams
Deck with in-situ RC/PC beams
Composite deck with steel girders
Composite deck with steel girders
Composite deck with steel girders
6
Transverse distribution of internal forces in
beam decks
7
Deflection of a beam-and-slab deck under axle load
Transverse-distribution coefficients for the
longitudinal bending moments Ratio between the
bending moment taken by one beam and the bending
moment that this beam would take in the case of a
uniform distribution
8
(No Transcript)
9
Factors affecting the transverse distribution of
longitudinal bending moments (I)
  • Transverse flexural stiffness of the slab The
    larger the transverse flexural stiffness of the
    beam-and-slab deck, the larger the required
    transverse shear load (V) for guaranteeing
    compatibility, the larger the transverse
    distribution of the applied load, the smaller the
    transverse-distribution coefficients
  • The larger the depth of the slab, the larger the
    transverse flexural stiffness of the
    beam-and-slab deck
  • The smaller the transverse spacing between beams,
    the larger the transverse flexural stiffness of
    the beam-and-slab deck

10
Factors affecting the transverse distribution of
longitudinal bending moments (II)
  • Torsional stiffness of the beams The larger the
    torsional stiffness of the beams, the larger the
    required transverse shear load (V) for
    guaranteeing compatibility, the larger the
    transverse distribution of the applied load, the
    smaller the transverse-distribution coefficients
  • The larger the torsional constant of the beams,
    the larger the torsional stiffness of the beams
  • The larger the restriction to the transverse
    rotation of the beams at the support sections,
    the larger the torsional stiffness of the beams

11
Factors affecting the transverse distribution of
longitudinal bending moments (III)
  • The stiffness of the beams The smaller the
    flexural stiffness of the beams, the larger the
    required transverse shear load (V) for
    guaranteeing compatibility, the larger the
    transverse distribution of the applied load, the
    smaller the transverse-distribution coefficients
  • The smaller the second moment of inertia of the
    beams, the smaller the stiffness of the beams
  • The larger the span, the smaller the stiffness of
    the beams
  • The smaller the restriction to the longitudinal
    rotation of the beams, the smaller the stiffness
    of the beams

12
Factors affecting the transverse distribution of
longitudinal bending moments(IV)
  • Eccentricity of the point load The larger the
    eccentricity of the point load, the smaller the
    transverse distribution of the load and the
    larger the transverse-distribution coefficients
  • Width/Span ratio The larger the width/span
    ratio, the smaller the transverse distribution of
    the load and the larger the transverse-distributio
    n coefficients

13
Transverse structural behaviour under uniform load
14
(No Transcript)
15
Transverse structural behaviour under eccentric
point load
16
  • (1) Transverse local bending
  • (2.1) Transverse local bending
  • (2.2) Longitudinal bending
  • (2.3.1) Warping torsion
  • (2.3.2) Distorsion

17
  • Deformation and longitudinal normal stresses due
    to
  • Total
  • Due to bending
  • Due to torsion
  • Due to transverse deformation and distorsion

18
Deformed shape
Transverse Shear forces
Longitudinal normal stresses
Horizontal Shear forces
Horizontal normal stresses
Transverse bending moments
19
Longitudinal normal stresses
Deformed shape
20
Modelling beam decks
21
  • One longitudinal member per beam plus additional
    beams representing the slab if this is required
  • Transverse members located at diaphragms,
    mid-span section plus intermediate sections
  • The ratio between the transverse spacing and the
    longitudinal spacing should not be larger than 2
    and smaller than 0.5

22
  • Second moment of inertia of the longitudinal
    members Second moment of inertia of the
    corresponding beam, with respect of the centroid
    of the complete section, considering effective
    width (or the corresponding slab section in the
    case of intermediate/end longitudinal members)
  • Torsional constant of the longitudinal members
    Torsional constant of the corresponding beam ½
    Torsional constant of the corresponding slab
    section
  • Second moment of inertia of the transverse
    members Second moment of inertia of the
    corresponding slab section, with respect of the
    centroid of the slab
  • Torsional constant of the transverse members ½
    Torsional constant of the corresponding slab
    section

23
(No Transcript)
24
REFERENCES CHEN, W. F. AND DUAN L. 2003. Bridge
Engineering. CRC Press LLC HAMBLY, E.C. 1991.
Bridge Deck Behaviour. Spon Press. PARKE G,
HEWSON N. 2008. ICE manual of bridge engineering.
ICE. MANTEROLA, J. BRIDGES. (6 Volumes, in
Spanish). ETSICCP, Madrid
Write a Comment
User Comments (0)
About PowerShow.com