Pier Head Reinforcement details Free DWG
This webcast will teach those new to the AutoCAD software how to obtain important information about objects in AutoCAD 2020. In this webcast, learn how to:
* Use Quick Properties and Properties to obtain object information.
* Modify the properties of objects and also match the properties of two different objects.
* Obtain exact measurements of the objects using the measuring tools.
The content from this webcast is taken from Chapter 9 (Analyzing Model and Object Properties) of the ASCENT Learning Guide, AutoCAD 2020 Fundamentals.
Details
Title | Object Information in AutoCAD 2020 |
Duration | 49 Mins |
Language | English |
Format | MP4 |
Size | 109 MB |
Details
Title | Midas – Analysis and Design of 250m Long Underground Metro Station |
Duration | 39 Mins |
Language | English |
Format | MP4 |
Size | 112 MB |
Table of Contents
Bearings are mechanical systems which transmit loads from the superstructure to the substructure. In a way, bearings can be thought of as the interface between the superstructure and the substructure.
Their principal functions are as follows:
1.To transmit loads from the superstructure to the substructure, and
2.To accommodate relative movements between the superstructure and
the substructure.
Bearings may be classified in two categories:
1.Fixed bearings (allow rotations only)
2.Expansion bearings (allow both rotational and translational movements)
Following are the principal types of bearings currently in use:
1.Sliding Bearings
2.Rocker and Pin Bearings
3.Roller Bearings
4.Elastomeric Bearings
5.Curved Bearings
6.Pot Bearings
7.Disk Bearings
A pot bearing comprises a plain elastomeric disk that is confined in a shallow steel ring, or pot. Vertical loads are transmitted through a steel piston that fits closely to the steel ring (pot wall).
Translational movements are restrained in a pure pot bearing, and the gravity loads are transmitted through the steel piston moving against the pot wall. To accommodate translational movement, a PTFE sliding surface must be used. Keeper plates are often used to keep the superstructure moving in one direction.
In general, the movement accommodated by fixed and expansion bearings can be classified by the following:
Figure 1 : Types of Por Bearings
A non-reinforced elastomer is placed between a precisely milled steel pot and a cylindrical lid.
Vertical loads are transmitted through a steel piston that fits closely to the steel pot wall. Flat sealing rings are used to contain the elastomer inside the pot. The elastomer behaves like a viscous fluid within the pot as the bearing rotates. Because the elastomeric pad is confined, much larger load can be carried this way than through conventional elastomeric pads.
Figure 2 : Fixed Pot-Bearings
A Uniaxial Displaceable Pot Bearing (Guided Pot Bearing) releases the lateral movements of bridge in any one direction utilizing a guide on the lid and a guiding groove in the gliding plate.
The gliding ability is accomplished by the embedded PTFE (Teflon®) disc and the gliding austenitic steel, which is welded onto the bottom of the gliding plate.
Figure 3 : Guided Pot-Bearings
The Multiaxial Displaceable Pot Bearing (Sliding Pot Bearings) releases lateral movements of the bridge in all directions.
The gliding ability is accomplished by the embedded PTFE (Teflon®) disc and the gliding austenitic steel, which is welded onto the bottom of the gliding plate.
Figure 4 : Slidin Pot-Bearings
Figure 5 : Components of Pot-Bearing (Fixed Pot-Bearing)
Figure 6 : Components of Pot-Bearing (Guided Pot-Bearing)
First, the vertical and horizontal loads, the rotational and translational movements from all sources including dead and live loads, wind loads, earthquake loads, creep and shrinkage, prestress, thermal and construction tolerances need to be calculated. Then, the table below may be used to tabulate these requirements.
Table 1 : Bearing Schedule Requirements
Figure 7 : Steps to install Pot-Bearings
Figure 8 :Installation oof Pot-Bearings
The basic intent of this study is:
Table of Contents
Shrinkage cracks in concrete occur when excess water evaporates out of the hardened concrete, reducing the volume of the concrete.
Deformation of structure under sustained load. It’s a time dependent phenomenon. This deformation usually occurs in the direction the force is being applied. Like a concrete column getting more compressed, or a beam bending.
Creep does not necessarily cause concrete to fail or break apart. Creep is factored in when concrete structures are designed.
έDS= 0.5 x (-300×10-6)
Refer BS 8110 Clause 7.4.3.4 Table 29
RF = έDS x Ec x A(slab) x φ
RM = RF x eccentricity
Eccentricity = y top of composite section – half of slab thicknes
Restrained Stress (RS) = έDS x Ec x Ф
Axial Release (AR) = RF / X-sec area
Moment Release (MR) = RM x y / inertia
(for top and bottom stresses)
Σ(RS , AR , MR)
Σ(MR , AR)
Dead = 2.0, SDL = 2.3, Prestressing = 2.2
The objective of this presentation is to furnish design of curved bridges with a basic understanding of the configuration, geometric approximations and structural behavior and their interrelationship in simple structural loading system.
Why do we need joints?
Content: