GB/T 12897-2006 English PDF (GBT12897-2006)

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GB/T 12897-2006: Specification for the first and second order leveling
GB/T 12897-2006
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 07.040
A 76
Replacing GB 12897-1991
Specifications for the first and second order leveling
ISSUED ON. MAY 24, 2006
IMPLEMENTED ON. OCTOBER 01, 2006
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of the People's Republic of
China.
Table of Contents
Foreword ... 7 
1 Scope ... 8 
2 Normative references ... 8 
3 Terms and definitions ... 9 
4 Leveling network ... 10 
4.1 Elevation system and elevation reference ... 10 
4.2 Leveling accuracy ... 11 
4.3 Layout principles ... 11 
4.4 Benchmark layout density ... 12 
4.5 Line naming and benchmark numbering ... 12 
4.6 Connect leveling of new line and surveyed line ... 13 
4.7 Gravity survey on leveling lines ... 13 
4.8 Technical design of leveling network ... 14 
5 Point selection and stone burial ... 15 
5.1 Point selection ... 15 
5.1.1 Selection of leveling line ... 15 
5.1.2 Selection of benchmark position ... 15 
5.1.3 Selection of bedrock benchmark ... 16 
5.1.4 Work to be done after point selection ... 16 
5.1.5 Data to be supplemented during point selection ... 17 
5.1.6 Data to be submitted at the end of point selection ... 17 
5.2 Buried stone ... 17 
5.2.1 Type of mark stone ... 17 
5.2.2 Selected buried stone type ... 18 
5.2.3 Leveling mark ... 18 
5.2.4 Mark stone burial ... 18 
5.2.5 External finishing of mark stone ... 24 
5.2.6 Control of key procedures ... 25 
5.2.7 Land occupation and hosting of leveling mark stone ... 25 
5.2.8 Stabilization time limit for leveling mark stones ... 26 
5.2.9 Data to be submitted at the end of stone burial ... 26 
5.2.10 Inspection and maintenance of leveling mark stone ... 26 
6 Instruments ... 27 
6.1 Selection of instruments ... 27 
6.2 Instrument calibration ... 27 
6.3 Instrument technical indicators ... 29 
7 Leveling observation ... 31 
7.1 Observation method ... 31 
7.2 Observation time and weather conditions ... 31 
7.3 Setting up survey stations ... 32 
7.4 Survey station observation sequence and method ... 32 
7.4.1 Optical level observation ... 32 
7.4.2 Digital level observation ... 34 
7.5 Suspension and detection ... 35 
7.6 Observation tolerance and settings for survey station ... 36 
7.6.1 Observation tolerance of survey station ... 36 
7.6.2 Direct and reversed starting survey station setting for digital leveling
instrument leveling section ... 36 
7.7 Matters to observe during observation ... 37 
7.8 Observations of various elevation points ... 38 
7.9 Observing nodes ... 39 
7.10 Detection made in connect leveling or adjoining leveling of new and old
lines ... 39 
7.11 Round-trip observation height difference discrepancy and loop closure error
... 40 
7.12 Repeated leveling and selection of results ... 40 
8 Cross-river leveling ... 42 
8.1 Scope of application ... 42 
8.2 Selection of leveling method ... 42 
8.3 Site selection and layout ... 43 
8.4 Cross-river leveling observation requirements ... 47 
8.5 Number of observation sets and tolerances ... 49 
8.6 Optical micrometry ... 50 
8.6.1 Preparation ... 50 
8.6.2 Observation methods ... 50 
8.7 Tilting screw method ... 51 
8.7.1 Preparation ... 51 
8.7.2 Observation methods ... 51 
8.8 Theodolite inclination method ... 53 
8.8.1 Preparation ... 53 
8.8.2 Observation methods ... 53 
8.9 Ranging triangle elevation method ... 54 
8.9.1 Preparation ... 54 
8.9.2 Determination of inter-point height difference at survey station at this bank
... 55 
8.9.3 Distance measurement ... 56 
8.9.4 Vertical angle observation ... 57 
8.9.5 Discrepancy of height differences between observation sets ... 58 
8.9.6 Repeated leveling and selection of leveling results ... 59 
8.10 GPS leveling method ... 60 
8.10.1 Technical requirements ... 60 
8.10.2 Point selection ... 60 
8.10.3 Burial of mark stone ... 61 
8.10.4 Instrument and equipment ... 61 
8.10.5 Field observations ... 61 
8.10.6 GPS observation records ... 63 
8.10.7 Data processing and result calculation ... 63 
8.10.8 Cross-river leveling GPS network adjustment ... 65 
8.10.9 Height difference calculation ... 66 
8.10.10 Additional leveling and repeated leveling ... 67 
8.11 Leveling on Ice ... 67 
8.12 Night observation ... 68 
9 Records, arrangements, and calculations of field achievements ... 68 
9.1 Recording methods and requirements ... 69 
9.1.1 Recording method ... 69 
9.1.2 Record items ... 69 
9.1.3 Handbook record requirements ... 69 
9.1.4 Arrangement and inspection of observation records ... 70 
9.2 Field calculation ... 70 
9.3 Inspection and acceptance of field achievements and submission ... 72 
9.3.1 Inspection, acceptance and quality evaluation of achievements ... 72 
9.3.2 Technical summary ... 72 
9.3.3 Submission of information ... 72 
Appendix A (Normative) Drawing format of selected stone burial data and mark
stone fabrication and burial descriptions ... 74 
A.1 Tools for point selection and stone burial ... 74 
A.2 Drawing of leveling line map ... 74 
A.3 Drawing of benchmark description ... 77 
A.4 Drawing of leveling network node adjoining leveling map ... 80 
A.5 Leveling mark map ... 81 
A.6 Leveling mark stone cross section ... 84 
A.7 Leveling mark stone material consumption and concrete construction
requirements ... 92 
A.8 China frozen soil extreme depth contour line ... 95 
A.9 Leveling mark entrustment book ... 97 
Appendix B (Normative) Instrument inspection method ... 100 
B.1 Visual inspection of leveling scale ... 100 
B.2 Calibration of circular level on leveling scale... 100 
B.3 Determination of division plane bending difference of leveling scale ... 100 
B.4 Determination of zero inequality difference and basic and auxiliary division
reading difference of a pair of scales ... 101 
B.5 Determination of verticality of leveling scale center axis and scale bottom
surface ... 104 
B.6 Visual inspection of leveling instrument ... 107 
B.7 Calibration of approximate leveler on leveling instrument ... 108 
B.8 Determination of lost motion and division values for leveling instrument
optical micrometer ... 109 
B.9 Determination of mean square error in level sight line observation ... 112 
B.10 Determination of automatic leveling instrument compensation error ... 116 
B.11 Calibration of leveling instrument reticule ... 121 
B.12 Determination of stadia constants for leveling instrument ... 121 
B.13 Determination of leveling instrument focusing lens run error ... 123 
B.14 Determination of transposition error of bubble level ... 128 
B.15 Calibration of leveling instrument i angle ... 129 
B.16 Determination of the swing difference 2C angle of double-position
automatic levelling instrument ... 131 
B.17 Determination of mean square error and vertical axis error of survey station
height difference observation by leveling instrument ... 133 
B.18 Determination of tilting screw lost motion, division error, and division value
of leveling instrument ... 136 
B.19 Determination of leveling instrument coincident leveler division value .. 140 
B.20 Determination of theodolite vertical dial micrometer run error ... 146 
B.21 Determination of mean square error in vertical angle observation in one
observ...