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GB/T 12897-2006 PDF in English


GB/T 12897-2006 (GB/T12897-2006, GBT 12897-2006, GBT12897-2006)
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GB/T 12897-2006: PDF in English (GBT 12897-2006)

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 & 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 & 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
observation set of theodolite ... 148 
B.22 Inspection of digital leveling instrument sight line length measurement error
... 151 
Appendix C (Normative) Vane production and observation record for cross-river
leveling ... 153 
C.1 Production of cross-river leveling vane ... 153 
C.2 Cross-river leveling observation records ... 155 
Appendix D (Normative) Observation handbook format and height difference
table preparation ... 174 
D.1 First and second order leveling field observation handbook ... 174 
D.2 Calculation of leveling field work height difference correction ... 177 
D.3 Leveling field work height difference and approximate elevation table ... 183 
D.4 Wind scale ... 185 
Specifications for the first and second order leveling
1 Scope
This standard specifies the layout principles, leveling methods, and accuracy
indicators for the establishment of the first and second order leveling networks
throughout the country.
This standard applies to the layout and survey of the state first and second
order leveling network. Regional precise leveling networks can also make
reference to it.
2 Normative references
The provisions in following documents become the provisions of this Standard
through reference in this Standard. For the dated references, the subsequent
amendments (excluding corrections) or revisions do not apply to this Standard;
however, parties who reach an agreement based on this Standard are
encouraged to study if the latest versions of these documents are applicable.
For undated references, the latest edition of the referenced document applies.
GB/T 3161 Optical theodolite
GB/T 10156 Level
GB/T 16818 Specifications for short to medium ranges electro-optical
distance measurements
GB/T 18314 Specifications for global positioning system (GPS) surveys
GB 50007-2002 Code for design of building foundation
CH 1001 General rules for drafting technical summaries of surveying and
mapping
CH 1002 Specifications for inspection and acceptance of surveying and
mapping products
CH 1003 Standard for quality assessment of surveying and mapping
products
CH/T 1004 General rules for technical design of surveying and mapping
CH/T 2004 The general rules of the electronic data recording for field
surveying
CH/T 2006 The electronic data recording rules for leveling
JJG 8 Specifications for leveling rule verification
JJG 414 Verification regulation of optical theodolite
JJG 425 Verification regulation of levels
JJG 703 Verification regulation of electro-optical distance meter (EDM
instruments)
JJF 1118 Calibration specification for global positioning system (GPS)
receiver
3 Terms and definitions
The following terms and definitions apply to this standard.
The following terms and definitions apply to this standard.
3.1
Node
The benchmark in the leveling network that connects at least three leveling
lines.
3.2
Leveling line
Leveling line between two adjacent nodes in the same order leveling network.
3.3
Section
Leveling line between two adjacent basic benchmarks in a leveling line.
3.4
Leveling section
Leveling line between two adjacent benchmarks.
3.5
f) Locations that may be destroyed or inconveniently observed due to
construction in the short term;
g) Filling sections of road.
5.1.3 Selection of bedrock benchmark
The bedrock benchmarks should be selected on the outcrop of the bedrock or
bedrock not deeper than 5 m above the ground. The selection of bedrock
benchmarks shall be attended by geologists, to collect and analyze existing
data, to make field survey to understand the geological structure, the nature of
rocks and soils, adverse geological phenomena and groundwater. If the existing
data does not meet the requirements, the necessary exploration shall be carried
out. After the selection of the bedrock benchmark, the geological survey report
shall be prepared point by point and submitted. The contents of the geological
survey report are as follows.
a) The geodetic coordinates, topography, geomorphology, geological
structure, adverse geologic phenomena, stratum formation condition,
physical and mechanical properties of rock and soil of the benchmark
positions;
b) The stability of foundation, uniformity of rock and soil and allowable
bearing capacity, depth of groundwater and extent of change, maximum
soil freezing depth and thawing depth, engineering geological hazards
that may occur after the setting of benchmarks, and construction
proposals;
c) The engineering geological profile within 50 m around the point and the
benchmark pit geodetic column map.
The preparation of the geological survey report shall be carried out in
accordance with the provisions of clause 3.0.3 of GB 50007-2002.
5.1.4 Work to be done after point selection
After each benchmark position is selected, a point mark with a noted number
and a mark stone type shall be set up. In accordance with the requirements of
A.3, it shall fill and draw the description of benchmark based on the format as
shown in Figure A.2. In the course of selecting the leveling line, the leveling line
map shall be drawn section by section in accordance with the requirements of
A.2. The pattern is shown in Figure A.1. For the nodes of the leveling network,
it shall fill the node connect leveling map in accordance with the requirements
of A.4 based on the format as shown in Figure A.3.
the culvert and is used to accommodate the lower mark. In the culvert,
pour concrete to the lower mark hole, place the lower mark, pour concrete
to the culvert top end, use vibrating bar to tamper it in layers to exhaust
he bottom gas. In the center of the culvert, a leveling mark shall be placed
at the center of the culvert. Place the leveling mark at the center of the
culvert top, which shall be upright, straight, and head to north, smoothen
the concrete top surface. After the initial setting of the concrete, add the
mark protective cover and cementer protective cover (inside of the iron
protective cover shall be coated with butter), make external decoration.
The burial specification and shape are as shown in Figure A.9.
5.2.4.2 Burial of rock stratum leveling mark stone
For the burial of basic leveling mark stone or common leveling mark stone on
the outcrop rock stratum, it shall remove the surface weathering material, drill
a hole with a depth of not less than 0.15 m and an opening diameter of not less
than 0.2 m on the hard rock plane, clean the hole, pour concrete to embed the
leveling mark, which shall be embedded uprightly and straightly, after the initial
set of concrete (about 1 h at normal temperature), add the mark protective
cover and cementer protective cover (inside of the iron protective cover shall
be coated with butter), make external decoration. It is prohibited to bury
benchmark on isolated rocks that rise above the ground. Burial specifications
and shapes are shown in Figure A.10 and Figure A.14.
5.2.4.3 Burial of concrete column leveling mark stone
5.2.4.3.1 Prefabricated steel framework
The framework of the concrete column stone uses 3 pieces of foot rebars with
a diameter of 10 mm and wrapping rebars with a diameter of 6 mm. A ring of
wrapping rebar is applied at the interval of 0.3 m to tie it into a triangular prism.
The two ends of the foot rebar are bent into semicircles with a diameter of 25
mm, the wrapping rebar for basic leveling mark stone is encircled into an
equilateral triangle with a side length of 150 mm, the wrapping rebar for ordinary
leveling mark stone is encircled into an equilateral triangle with a side length of
100 mm. The both ends of the wrapping rebar are overlapped and tied firmly.
The length of the tied steel framework is equal to the length of the concrete
column plus 0.1 m.
The steel framework of the concrete base is cross-braided by a 10 mm diameter
steel bar into mesh form, the both ends of the steel bar are bent to a semi-circle
with a diameter of 25 mm. The specifications and shapes are shown in Figure
A 11 and Figure A.15.
5.2.4.3.2 Digging mark stone pit
Use the selected point mark as the center to dig the mark stone pit, the size of
which shall be convenient for work and the depth of which shall be in
accordance with the provisions of Table A.3.
5.2.4.4.2.2 Burial of prefabricated steel tube leveling mark stone
For the prefabricated steel tube basic leveling mark stone, it shall pour the mark
stone cushion at site, using the building method same as that for the base of
the concrete column leveling mark stone in 5.2.4.3.3. For the steel tube ordinary
leveling mark stone, pave a 20 mm ~ 40 mm thick cement mortar at the mark
stone pit bottom as a cushion.
After the initial setting of the cushion, the prefabricated steel tube leveling mark
stone shall be placed vertically in the center of the cushion. The lower mark of
the basic leveling mark stone shall be set on the north side, and the pit shall be
backfilled and externally finished.
5.2.4.4.2.3 Site pouring steel tube leveling mark stone
After the initial setting of the cushion, place the steel tube leveling mark stone
base model plate at the center of the cushion, vertically place the steel tube
which is subject to antiseptic treatment and equipped with steel root at the
center of the model plate, the lower mark of the basic leveling mark stone shall
be facing north. Pour base concrete and tamper it in layers, remove the mold
after the concrete is solidified (about 12 hours at room temperature), backfill the
pit and do the external finishing.
5.2.4.4.3 Burial of steel tube leveling mark stone at permafrost area
When mechanical drilling is used, underground installations such as tap water,
gas pipelines, optical cables and cables shall be avoided. Depth shall be in
accordance with the provisions of Table A.3. Place the steel tube which is
subject to antiseptic treatment and equipped with steel root in the drilling hole,
the lower mark of the basic leveling mark stone shall be facing north, pour
concrete to the thawing depth line, tamper it in layers, backfill pit with soil and
make external finishing.
5.2.4.5 Burial of road leveling mark stone
When mechanical drilling is used, underground installations such as tap water,
gas pipelines, optical cables and cables shall be avoided. Depth shall be in
accordance with the provisions of Table A.3. Insert a PVC pipe with an outer
diameter of not less than 110 mm and a wall thickness of not less than 3 mm
into the hole, and distribute evenly 10 ~ 12 holes with a 15 mm hole diameter
on the pipe wall approximately 0.5 m from the bottom of the pipe. Pour 1.1
cement mortar into the pipe and the gap at the lower part of the pipe. The upper
part is glued with the leveling mark with PVC glue. The mark is then fixed to the
e) In case of burying mark stones in the mountains and forest areas, the
azimuth stake can be installed on the roadside closest to the benchmark;
the azimuth stake can be made of wood, stone, concrete or metal
materials, the painting or embossing method is used to mark the point
number and point direction at an eye-catching position, and indicate the
stake direction and distance of the azimuth stake in the description of point.
5.2.6 Control of key procedures
At the construction site where the mark stone is built, the following photographs
shall be taken.
a) Photographs of reinforcing steel framework, which shall reflect the shape
and size of the framework bundles;
b) Photographs of the mark stone pit, which shall reflect the shape and size
of the mark stone pit and base pits;
c) The photographs of the base after construction, which shall reflect the
base shape and whether the placement of the steel framework or
prefabricated culvert is correct;
d) The mark placement photographs, which shall reflect whether the mark is
placed straightly and uprightly;
e) The photographs of mark stone after finishing, which shall reflect whether
the mark stone is finished in a normalized manner;
f) The long-range photographs of the locations where the mark stones are
buried, which shall reflect the landform and landscape features of the
locations where the mark stones are buried.
5.2.7 Land occupation and hosting of leveling mark stone
After the position of the leveling point is selected, the land occupied by the mark
stone shall be approved by the land users and managers.
During the process of mark stone burial, the statutory duties and precautions
for the protection of survey marks shall be publicized to the local people and
cadres. After the completion of the mark stone burial, the relevant government
departments at the local township level or above (road level points to the road
management department) shall go through the entrusting procedures. The
format of the entrusting book is shown in Figure A.27.
7 Leveling observation
7.1 Observation method
7.1.1 The first and second order leveling uses a single line round-trip
observation. The round-trip observation for the same section shall use the same
type of instrument and turn-point pin along the same road.
7.1.2 In each section, first perform continuous direct observation (or reversed
observation) for all leveling sections, then perform continuous reversed
observation (or direct observation) for all leveling sections. If the section is
relatively long, it may also divide the section into several sub-sections of 20 km
~ 30 km, to perform the direct and reversed observation for all leveling sections
continuously in the sub-section.
7.1.3 The direct (or reversed) observation and reversed (or direct) observation
for the same leveling section shall be made in the morning and afternoon,
respectively. In the case of cloudy days with relatively little change in daytime
temperatures and good observation conditions, the direct and reversed
observation for several mileages can be performed in the morning or afternoon
at the same time. But the total number of survey stations for this mileage shall
not exceed 20% of the total number of survey stations of this section for the first
order, or not exceed 30% of the total number of survey stations of this section
for the second order.
7.2 Observation time and weather conditions
Leveling observations shall be performed when the scale division line imaging
is clear and stable. The observations shall not be made under the following
conditions.
a) Within 30 minutes after sunrise and before sunset;
b) Within about 2 hours before and after the sun midheaven (which may be
increased or decreased appropriately in accordance with the region,
season and weather conditions, the minimum interval time shall not be
less than 2 h);
c) When the image of the scale division line jumps violently;
d) When the temperature changes suddenly;
e) When the wind is too large that the scale and instrument cannot be
stabilized.
a) Basic divisions of the rear view scale;
b) Basic division of the front view scale;
c) Auxiliary division of the front view scale;
d) Auxiliary division of the rear view scale.
7.4.1.2 During direct leveling, the order of the even-numbered survey station
aiming scale division is.
a) Basic divisions of the front view scale;
b) Basic division of the rear view scale;
c) Auxiliary divisions of the rear view scale;
d) Auxiliary division of the front view scale.
7.4.1.3 In case of reversed observation, the order of the odd and even survey
station aiming scales is the same as that of the odd and even stations of the
direct observation.
7.4.1.4 The optical micrometry method is adopted for the survey station
observation. The operating procedure of a survey station is as follows (using
the odd survey station of reversed observation as an example).
a) First level the instrument (when the bubble-type level instrument telescope
rotates around the vertical axis, the separation of the image at both ends
of the leveling bubble must not exceed 1 cm. The circular bubble of the
automatic leveling instrument is located in the center of the index ring).
b) Align the telescope to the rear view scale (in this case, use a circular
leveler on the scale to set the scale vertically), so that the images at both
ends of the leveler are almost coincided (the double-position automatic
leveling instrument shall be placed in the Ith position). Then use the upper
and lower wires to aim the scale basic division to take the stadia reading.
The fourth digit of stadia is read directly by the micrometer drum. Then,
make the coincidence leveler bubble to be accurately coincided, turn the
micrometer drum, use the wedge-form bisector wire to accurately aim the
scale’s basic division, read the basic division of the scale and the
micrometer drum reading (to the minimum division of the micrometer
drum).
c) Rotate the telescope to aim at the front view scale, make the images at
both ends of the coincidence leveling bubble be coincided accurately (two-
position automatic leveling instrument is still at the Ith position), use the
wedge-form bisector wire to accurately aim the scale basic division, read
positioned in a vertical position on a circular level). Use a vertical wire to
aim the center of the bar code. Focus on the bar code accurately and
press the measurement key.
c) After displaying the readings, rotate the telescope to aim the center of the
front view scale bar code, accurately perform focusing until the bar code
image is clear, press the measurement key;
d) After readings are displayed, re-aim the front view scale, pressure the
measurement key;
e) After the readings are displayed, rotate the telescope to aim the center of
the bar code of the rear view scale. Accurately perform focusing until the
bar code image is clear, press the measurement key, to display the survey
station results. After the station is verified as qualified, transfer the survey
station.
7.5 Suspension and detection
7.5.1 In case of suspension of observations, it is best to end the observation at
the benchmark. Otherwise, it shall select two fixed points which are stable and
reliable, smooth and projected, and easy to place scale from the last survey
station as the suspension point. If there is no fixed point, it shall properly
arrange the turning-point pin of the last two survey stations (when using the
scale stand as the turning-point pin, it may use three wood stakes with snap
fastener) as the suspension point.
7.5.2 Suspension points shall be checked after the suspension, the height
difference measured before and after the suspension between any two points
shall be compared. If the tolerance (see Table 8) is met, the survey may start
from here; if the tolerance is exceeded, the instrument may be changed to
perform another checking; if it still exceeds tolerance, it shall be measured from
the previous benchmark.
7.5.3 Detection results shall be retained in the handbook, but not used when
calculating elevation differences.
7.5.4 The digital level measurement suspension can be checked by
establishing a new leveling section, etc. When there are difficulties in checking,
it shall be closed at a fixed point.
- High-end and low-end of the stadia tolerance
- High-end and low-end of the sight line high tolerance;
- Tolerance in front and rear stadia difference;
- Accumulative tolerance of front and rear stadia difference;
- Tolerance of the difference between the two reading height differences.
c) Job settings.
- Create job documents;
- Create a leveling section name;
- Select leveling mode. “αBFFB”;
- Enter the starting point reference elevation;
- Enter the point number (point name)
- Enter other leveling section information.
d) Communication settings. Operate in accordance with the instructions of
the instrument.
7.7 Matters to observe during observation
7.7.1 At 30 min before the observation, the instrument shall be placed in the
shadow of the open air, so that the instrument tends to be in line with the outside
temperature; when setting up the survey station, the umbrella shall be used to
shield the sunlight; when moving the survey station, the instrument shall be
covered. Before using a digital level, it shall also be warmed up, which is not
less than 20 single leveling.
7.7.2 For a bubble type level, the leveling zero point of the tilt screw shall be
measured and marked before the observation. The zero position shall be
adjusted at any time as the temperature changes. For the circular leveler of the
automatic leveling instrument, it shall be strictly leveled.
7.7.3 When the tripod of the leveling instrument is to be placed on successive
survey stations, the two feet shall be parallel to the direction of the leveling line,
and the third foot shall be alternatively placed on the left and right sides of the
line direction.
7.7.4 Except for the turning point of the line, the three positions of the instrument
The height difference result is taken as the median and then listed into the
height difference table, indicated by square ......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.