Construction lofting（施工放样作业）

1、Good is good, but better carries it.精益求精，善益求善。Construction lofting（施工放样作业）Construction lofting（施工放样作业）Construction lofting（施工放样作业）Setting out work (1)Construction lofting(1) construction survey lofting process flow diagram;(two) construction survey lofting method and requirements;I. instructionsThe

2、guide book is written according to the conventional method of lofting, lofting personnel must according to the actual situation, such as precision, the distribution of control points, the existing equipment, site conditions, calculation tool to select the measurement site and lofting pointsDifferent

3、 combinations of different design methods and different methods of nuclear examination.Different project and the same project of different stages, different parts of the lofting site accuracy requirements are different, so the accuracy requirements of the site and lofting points are not the same. Du

4、ring the operation, please strictly implement the "engineering survey specifications", "highway construction survey specifications" and "construction survey control procedures". The restriction mentioned in this book refers to the limitation of the specification. If the

5、re are special requirements in the design, it will be carried out according to the design requirements.Two, data collection and lofting plan formulation1. before surveying and setting out, the plane and elevation control data of the construction area shall be obtained from the legal and effective wa

6、y.2., according to the site control point signs are stable and well, and so on, the existing control point data analysis, to determine whether all or part of the control points for testing.3., the existing control points can not meet the precision requirements, should be re layout control, the exist

7、ing control point density can not meet the needs of lofting, should be encrypted according to the existing control points.4., according to the formal design drawings, documents, modify notice of measurement lofting, not with oral notice and unauthorized drawings lofting.5., according to the specific

8、ations and design requirements of precision, and combined with personnel and equipment conditions, formulate measuring lofting plan. Its contents should include: detection and encryption of control points, laying out basis, setting out method and precision estimation, lofting procedures, personnel a

9、nd equipment allocation, etc.Three. Prepare before setting out1. read the design drawings, calculate the building outline, control points, data and dimensioning, and record the results.2., select the measuring lofting method, and calculate the lofting data, or write measurement lofting calculation p

10、rogram, draw out lofting sketch, and by the second independent check.3. instruments and tools used for the preparation must be within the effective calibration period. To charge the instrument, check the routine settings, such as unit, coordinate mode, compensation mode, prism type, prism constant,

11、temperature, air pressure, etc.4., with the memory of the total station instrument, you can advance control points (including the intended sites, checkpoints) and lofting points coordinate data into the instrument memory, and check.Four, total station coordinate method set station + polar coordinate

12、 method release pointIn the 1. control points set up the total station and in leveling, after initialization check the instrument settings: temperature, pressure, constant input (transferred) prism; 3D coordinate measurement site, measuring instrument and high input, the input (in) after the view co

13、ordinate, awarded after the point of view of rear view. If the back view has a prism and the input prism is high, the coordinate and elevation of the post view can be measured immediately and checked with the known data.2. aim at the other control point, check the azimuth or coordinate; erect the pr

14、ism or ruler at another known elevation point, and check the instrument's sight height. When calculating the function of the instrument itself, the record keeper should also perform the appropriate calculation to check the correctness of the input data.3. erect the tripod and prism on each test

15、site, take, record and input prism height, measure and record the coordinates and elevation of the site to be determined. The above procedure is for site measurement.4. in the measurement site according to step 1 placed the total station, another station to check a vertical mirror coordinates and el

16、evation.5. the recorder calculates the distance and azimuth of the measuring station to the setting out point according to the coordinate of the measuring station and the setting out point.6. the observer rotates the instrument to the azimuth of the first setting point, directing the director to mov

17、e the prism to the instrument's line of sight, measuring the distance from the D.7. calculate the difference between the measured distance D and the setting distance D degrees: D=D-D degrees, and the command director goes forward or backward on the line of sight, Delta D.8. repeat process 7 unti

18、l Delta D is less than lofting limit. (non hard ground can be driven at this time)NineCheck the azimuth value of the instrument, the prism bubble strictly Center (when necessary erection of three tripod), and then measured once, if the delta D is less than the limit requirements, you can accurately

19、calibrate the point.10. measure and record the coordinates and elevation of the site setting out points, compare with the theoretical coordinates. After confirming the mistake, add a note beside the sign.11. repeat 610 of the process, staking out all the points to be set out at the station.12. if a

20、station cannot all be lofting lofting points, can be in another station on the station to start setting out, have been released but also detected before 2 to 3 sampling points, the difference should not exceed the allowable deviation of point setting.13. after all the lofting and lofting are complet

21、ed, the random number of lofting points shall be determined and recorded, and the difference shall be no more than the allowable deviation of the lofting points;14. after the job is over, the Inspector checks, calculates and signs the data.15. people will be responsible for setting out survey data a

22、nd record the results marked one by one comparison, at the same time check point between the geometry and structure relationship and the relative relationship of size and line records to verify the annotation data and setting out points without error.16. fill out the measuring and lofting samples.Fi

23、ve, total station (range finder) angle intersection method, set station + polar coordinate method loftingThe total station instrument (Ce Juyi) is erected on the unknown point P and leveled;1. Place the prism on the known point A and measure the prism height;In 2, B, C on the placement of known poin

24、t sighting mark. Measure the distance between PA, D, elevation DH and PA to PB,PC horizontal angle between directions, alpha, beta.A group of 3 points, with the coordinate calculation of coordinates D, A, B and alpha point calculation; another group of coordinate by coordinate D, P A, C beta and the

25、 difference between the two groups; coordinates do not exceed the specified limit, the number is the final coordinates of the point P.4, according to the elevation of A points, HA and elevation difference DH, the instrument's line of sight is high: H, depending on =HA-DH.5. if the need can be p

26、coordinate projection to the ground, and mark. Measuring instrument for high elevation of ground point P.6. start with the polar coordinate method, and the lofting process is the same as that of "four, 416".Six, theodolite angle measuring method and polar coordinate method lofting1. in the

27、 unknown point placement of Theodolite (or total station, when a known point inconvenient prism), leveling; placement of sighting mark a known point in A, B, C, D.2., the far point of the four point A is zero, and the direction measurement method is used to measure the two values of A, B, C, D and A

28、;3. coordinate measuring data are divided into two groups of P site were calculated using resection procedure; difference of two coordinates do not exceed the specified limit, the number of points as last coordinates.4. if the station within 200 meters around two known elevation plane and elevation

29、control points, lofting accuracy is not high (greater than 5 cm), can observation instrument to the two control point two the zenith distance measurement, two eyes were used to inverse trigonometric leveling station instrument high (if high precision or distance greater than 200 meters, to join the

30、ball gas correction). If the difference does not exceed the limit, the preferred number is the instrument's line of sight.5. if necessary, the instrument center, coordinate or elevation can be projected onto the ground for marking.6. using the polar coordinate method to select the control points

31、 of a lofting, far as the direction of visual configuration (configuration dial to zero direction or azimuth direction), with a control point inspection visual direction difference should not exceed the limit request. If the accuracy of the lofting site is higher and the direction of inspection exce

32、eds 20, the direction of the setting shall be corrected.7. the recorder calculates the distance and azimuth of the measuring station to the setting out point (or the angle relative to the rear view) according to the coordinate of the measuring station and the setting out point.8. observer rotation t

33、heodolite to the first point setting direction, command Rodman with ruler from the station along the horizontal distance calculation the D degree of point setting direction, and calibration down.9, if the amount can not be directly taken from, can measure with ruler from the instrument center inclin

34、ed distance to the measuring and setting out.Zenith distance (or vertical angle) calculates the horizontal distance D, and the theoretical distance is D degrees: D=D-D degrees,The D with the ruler in the theodolite calibration point along the line of sight, lofting. (non bedrock and concrete ground

35、can be driven at this time)10. repeat the 8 and 9 steps to set out all the desired lofting points of the station.11. a control point, check the rear direction.The distance between the 12. ruler measurement lofting points, compared to check with the theoretical value, the difference should be less th

36、an the permissible error of point setting value.13. people will be responsible for setting out survey data and record the results marked one by one comparison, at the same time check point between the geometry and structure relationship and the relative relationship of size and line records to verif

37、y the annotation data and setting out points without error;14. if a station can not set out to all out at this time, using the polar coordinate method in station survey stations, second stations, but also began to have been released before the detection of lofting 2 3 points, the difference should n

38、ot exceed the permissible error of point setting; then continue until the lofting lofting all the necessary setting out point.15. after the job is over, the Inspector checks, calculates and signs the data;16. draw the measuring and lofting samples.Seven 、 direction intersection method lofting1, each

39、 of the two plane control points A and B is equipped with a theodolite, and the other control points are left behind, and the coordinates and azimuth angles of the dial are configured.2, calculate A, B points to the proposed lofting point P squareBit angle alpha and beta.3. the rotating theodolite A

40、 makes the azimuth angle alpha, and the observer commands the drawing staff to draw a point near the intersection point of the two line of sight (P1P2).4. rotating theodolite B, so that the azimuth is beta, observers command drawing personnel in the vicinity of the line of sight two draw points P3P4

41、.5. with a taut thin line, P1P2 and P3P4 determine the location of the intersection point M.6., two instrument panel, right rear view control point, and configure dial, repeat 35 steps to get the intersection of N.7. when the distance between M and N is less than the requirement of setting out the p

42、oint limit, the center line of M and N is used as the setting out point P and calibrated.8. repeat the above process, release other lofting points, and measure the distance between the lofting points and check the calculated value.Eight, inverted mirror, drop point method, single direction setting s

43、tation1., in order to erect the instrument on the line between the known points A and B, the instrument is used to approximate the O1 points on the A and B lines, and the instruments are leveled and the approximate distance of OA is estimated.The 2. is aimed at the distal A mirror, vertical telescop

44、e near B, estimate the crosshairs center point B1 and point B distance BB1; inverted mirror at A point, the vertical telescope, estimated cross center and B distance BB2; average value of BB1 and BB2 for BB.3. calculate the /AB value in OO1=OA * BB, and move the instrument to the AB line according t

45、o the B1 deviation from the B direction OO1.4. leveling instrument, repeat 23 steps, until the left, right disk, cross wire center position, the midpoint of the connection line B and B points coincide.5., the mirror, inverted mirror aimed at B points, vertical telescope, left and right cross wire ce

46、nter of the average position should fall at A points, at this time the instrument center point O projection to the ground, and make the mark, then O point in the AB line.6., after the A point, you can put a single line of direction. On the basis of this, the vertical (transverse) pile number of O po

47、ints can be calculated by the method of axis intersection, so as to set out the vertical (transverse) axis.Nine, axis intersection method, set station + direction line method, release line1. first with the inverted mirror point method (or direction line method), the instrument is erected at the know

48、n point between A and B on the line, a point of O1, leveling instrument.2. direction measurement method was used to measure the two back directions of A, C, B and D control points, and the angle alpha and beta were calculated;3., calculate the horizontal (vertical) coordinates of O1 points: Y01 '

49、;, =YC- (XC-XB), /TAN alpha, Y01, =YD- (XD-XB), /TAN beta. If the difference between Y01 'and Y01' does not exceed the limit, take the middle number as the O1 point vertical (horizontal) coordinate, and compare with the O point vertical (horizontal) coordinate, calculate the travel value OO1

50、.4. observer command operator using the ruler in AB axis from point O1 to measure OO1 distance, the O point set.5. in the O point instrument, after the A point (or B point), check the B points (or A points), rotate 90 degrees, release the O point in the longitudinal (transverse) axis.Ten 、 direction

51、 line translation methodIn a certain direction lofting line PY, using the free station method can not be directly mounted on the instrument P, P or not is elevated, at this time as close as possible to the point P on the P1 set up equipment, coordinate station method measuring P1 with resection of f

52、reedom (if the P1 coordinates are known, this step, then use the arrow line) PY direction line lofting method of translation.1. place the instrument at the 'P' point, the rear view control point A, and check the azimuth angle with the control point B.2. the rotating instrument makes the line

53、 of sight parallel to the projected axis (the azimuth angle is equal or difference 180 degrees). The conductor is marked with P1, P2 'and P3' in the parallel line on the ground. PN'.3., from P1 ', P2', P3'. PN 'with a small ruler to PY direction line side vertical distanc

54、e from DX, P1, P2, P3. PN, then P1, P2, P3. PN is the point on the line in the PY direction. Mark the single direction point and note the number of the pile.4. check the azimuth angle of the rear view and check the size of the line between the setting line and the existing structure of the building.

55、Construction lofting work (2)Eleven, traverse method (polar coordinate method) set up a stationIn the 1. control point A installed on the total station (Ce Juyi), placed in sighting mark control points B, C, placement of tripod and prism in undetermined point on P weight, height of instrument and pr

56、ism.2. B, C as a zero direction, another point as the inspection direction, with the direction of observation method to measure the level of P two measured back angle.3. measuring instruments to p zenith distance (vertical angle) two survey.4. measure the distance, distance, elevation, temperature a

57、nd air pressure to be measured.The tripod 5.A points and points of real exchange, instruments and measuring instruments to the prism, P A zenith distance (vertical angle) two measurement, measurement of return measured oblique distance, horizontal distance and height difference, temperature, pressur

58、e.6. use slope distance, zenith distance, temperature, air pressure, instrument height, prism height and instrument adding and multiplying constant to calculate the distance and elevation difference, and check the distance and elevation difference.7. A point coordinates and measuring azimuth angle, the horizontal distance in number, height calculated P coordinates and elevation.8., if there are more than one point to be determined, a few points should be made up of a traverse for round-trip observat