Setting out construction works 01
- 1. Advance Surveying Setting out construction works Prof. Rajguru R.S. Civil Engineering Department (rajgururajeshcivil@sanjivani.org.in) Sanjivani College of Engineering, Kopargaon,MH,India
- 2. Lecture Outline Introduction Precautions Setting out of Bridge
- 3. Introduction: • Setting Out is the establishment of the marks and lines to define the position and level of the elements for the construction work so that works may proceed with reference to them. • To build according to plan contractor must have reference lines and point established on the field .the construction proceed according to these marks • Accurate setting out is therefore a fundamental part of the construction works, and errors can be very expensive and time consuming to correct. It should only be undertaken by competent persons, and all work should be thoroughly checked, preferably by different personnel. • Setting out is usually undertaken once the site has been subject to a condition survey and desk study, and has been cleared of any debris, unwanted vegetation or obstructions. Works necessary to create required levels may also have been completed before the layout process begins.
- 4. Precautions: 1. All vertical wooden post should be firmly fixed. 2. Kept all vertical post at same level 3. Railing should be straight and of standard size. 4. Joint of wooden railing should be strong. 5. Horizontal wooden railing should be at same level. 6. Diagonal check should be done for everyday work 7. Staff member or worker should not be allow to sit on railing. 8. Periodical checking should be done 9. All column mark on railing should visible &readable 10. Lime powder should be thoroughly mix with sand. 11. Marking with lime powder should be clear and distinct 12. All the work should be certified by RCC consultant & architect
- 5. Setting out of Bridge: • Location survey • Bridge surveying is necessary to locate a site, obtain information for design, and furnish lines and grades for construction. A reconnaissance survey is made at all possible sites. A preliminary survey is made at the best site to establish horizontal and vertical control and to obtain information for the bridge design and construction planning. A location survey is made to layout the bridge according to the bridge plans. • Topographical map should have following details • North south • River name & flow direction • Town name • Road width/ railway width over bridge • Approach road detail • Approach road
- 6. Setting out of Bridge: • Details of Bench mark • Low and high water level • Maximum discharge and velocity from catchment area • The result of boring & trial pit • Location survey for pier • Locating survey of pier carried out in two stages first center line of bridge is fixed up and then piers are located on center line • Let A and B be the end points on the center line of bridge on either bank of the river & it is required to determine the length AB.
- 7. Locating piers for a bridge: • Method I : • Set out AD perpendicular to AB & measured AD accurately • Set theodolite at point D & measure angle ADB = 𝞱 • To check the length AB, set out a line BC ⏊ to AB at pt. B. • Measure the length BC & the angle BCA Then • AB=BC tanα, ∠BCA = α • The mean of the two taken as the length of the center line.
- 8. Locating piers for a bridge: • Method II • The base line AB & CD are laid on banks at ⏊ to the center line of bridge. • Divide base line laid on each bank into equal segments e.g. 1- 2, 2-3 etc. • On Center of bridge pier1 is located by sighting from both base line simultaneously, which make an angle of 45 with base line. • In the same manner center point of pier2 & 3 mark at the intersection of two intersecting lines 2-2 & 3-3 respectively.
- 9. Locating piers for a bridge: • Method III • In quadrilateral PQRS eight angles are carefully measured with theodolite by repetition method. • The base line PS & QR are measured. The length of the base line QR is calculated from the corrected length of PS and adjusted values of the angles and these values are then compaired with the measured values of PS & QR. • It is more accurate and precise method.
- 10. Thank you