COSC 301 Construction Surveying & Layout Activity VI Transit; Existing Building (As built) and Vertical Angles

Transcription

1 COSC 301 Construction Surveying & Layout Activity VI Transit; Existing Building (As built) and Vertical Angles Introduction 1. Review chapter 4 The Digital Transit and watch and understand chapter 5 Control Lines, Back Sight Lines, & Building Layout. 2. This activity will test your ability to set up and use a digital transit and apply it to vertical angular measurement and to conduct a small building as built survey. It will test your knowledge, understanding and application of the following concepts covered in Chapters 4 & 5: Theodolite Setup for Linear and Angular Measurements Building Invert Measures Application of Basic Trigonometry Functions Field Book Record Keeping 3. Each crew will be responsible for establishing the existing beam heights and elevations using vertical distances and angles measured in the Langford Building A with a surveyor s theodolite, recording the data in their field book, and reporting the results of their field work. 4. The components of this activity are: A. This section of the activity will test your ability to set up and use a digital transit and apply it to vertical angular measurement to check the elevation of structural members. You are to set up your transit on the first floor outside of the IT Center and establish its horizontal position relative to the structural beams and hand rails. B. This portion of the activity will test your ability to utilize a digital transit in measuring the bottom of physical structures within a building by using an inverted grade rod. C. The third section will require you to apply your understanding of how to document and report your field measurements. 5. Survey equipment used: D. Theodolite E. Tripod F. Tripod Anchor Base G. Grade Rod H. 100 Engineering Tape Measure I. 25 Engineering Tape Measure J. String Line K. Gammon Reel with Plumb bob L. Blue Masking Tape NOTE: 1. Make sure that you do not allow your instrument to fall due to the slick concrete floor. There are tripod anchors in each locker that you will use to set your tripod up on. This will keep the legs from sliding out. 2. Do not leave any tape or marks on any of the Langford Complex property. Use the blue masking tape. 3. Do not use the grade rod to establish the Height of Instrument (HI). Use your 25 tape measure from the instrument s optic centerline to the floor beneath your tripod (see Figure 1). Complete the building as built survey exercise as directed. 4. The use of an auto level instrument to establish the sight level or a tape measure to measure the beam height will guarantee a 0 on the activity. 1

2 5. Attach your Gammon reel and plumb bob s metal loop to your string line to lower from the beam faces to locate the adjacent side s point on the floor (see Figure 1 & 2). The adjacent side is measured from the instrument Datum point to the intersection of the plumb bob and the floor. 6. Caution must be taken to insure student safety when identifying this intersection point. One crew member must be at the point of intersection while your crew is lowering the plumb bob. Figure 1. Optic Center Points Defacement of University Property Figure 2. Gammon reel and Plumb bob "It is unlawful for any person to damage or deface any of the buildings, statues, monuments, trees, shrubs, grasses, or flowers on the grounds of any state institutions of higher education (Texas Education Code Section )" The words damage or deface refer specifically to any and all actions, whether direct or indirect, that either diminish the value or mar the appearance of the physical environment. Section A Vertical Angle Measurement to Measure the Elevation of Existing Structural Members You are to set up your theodolite on the first floor outside of the IT Center and establish its horizontal position relative to the structural beams and hand rails. The concrete floor of the Langford building on which you will be surveying is flat. There is no significant difference in elevation in this hallway. The established Datum point of MSL elevation is indicated in Figure 3. The exact location of this datum point is at the discretion of the survey crew. Insure that you are at a far enough distance away from the beams so that you can effectively look through the instrument to make accurate measurements. You are to check the elevations (Datum + HI + Opposite Side) of the top and bottoms of the structural beams and rails supporting the 3rd & 4th floors shown in Figure 4. You are to calculate using your knowledge of Pythagorean s Theorem and trigonometry (b x tan(a)) the elevations of the top hand rail and bottom beams at the two locations (see Figures 5 & 6). The problem involves datum elevation, line of sight, distances, and right triangles. Notice that there is a chamfer on the top of the beam and/or concrete hand rail; you will need to take this chamfer into account to determine beam and rail heights. In other words, the point you have to measure is not there and certainly not obvious. The point you have to measure is the intersection of two surface planes. The face of the hand rail and the top of the hand rail. They do not intersect on the visible surface of the hand rail. You will need to construct a simple tool to accurately establish this point in space. 2

3 Figure 3. TBM for Measurement Figure 4. Elevations of Structural Beams 3

4 Figure 5. Pythagorean Theorem for Opposite Side Figure 6. Pythagorean Theorem Example Each crew member is responsible for producing the field book entries and field book sketch portion of this activity. The Datum of should be shown and dimensioned, as well as the HI, distance from edge of beam intersecting the line of sight, instrument angle recordings, and all dimensions from the floor to the top and bottom of each floor beam. Record the final measurement values in your filed book. From the 1st floor to (Example Values): TOHR4th Floor = BOB 4th Floor = TOHR3th Floor = BOB 3th Floor = Section B Inverted Rod Measurement to Measure the Elevation of Existing Structural Members Using you re the current setup your theodolite on the first floor outside of the IT Center establish its horizontal position relative to the structural beams and stair platform. This portion of the activity will test your ability to utilize a digital transit in measuring the bottom of physical structures within a building by using an inverted grade rod. You are required to determine the existing elevation of three locations, two are BOB (Bottom of Beam) and one is a BOP (Bottom of Platform); see Figures 7 9. As before your Datum is MSL elevation. Figure 7. Bottom of Beam #1 Location 4

5 Figure 8. Bottom of Beam #2 Location Figure 9. Bottom of Platform #1 Location Again, each crew member is responsible for producing the field book entries and field book sketches for of this portion of the activity. The Datum of should be dimensioned, as well as the HI measurement and the distances from the first floor to the beams or platform. Report the final measurement values in your filed book (Example values below) and provide sketches: Floor 1 to BOB 1 Invert = Floor 1 to BOB 2 Invert = Floor 1 to BOP 1 Invert = Submission #1 A6FB.pdf 1. By now you should have a good idea of what your field book entries must look like and therefore, no example will be provided. Include in your field books all measurements, calculations and sketches used to calculate the beam elevations and inverts. 5

6 2. Scan your own field book entries and save them as a PDF file. Name this file A6FB.pdf. Go to the course web site and upload your own PDF file. This file upload represents a finished product, and should be done as soon as your crew completes the field activity. Section C Survey Data and Field Measurements Submission Submission #2 Field Measurement and Data As a crew, log into the Assignments page of the course web site and select the link Submit Assignment Data and Scoring, then pick on the Assign #6 button. Your crew will be provided a form to enter both your crew s elevation measurements for both the invert elevations and the calculated vertical elevations, along with crew member participation; submit (check your submitted values), and score your data (by submitting the values again). DO NOT wait until the last minute. All activities are due prior to the next assignment period or as directed. 6