CN111998825A - Monitoring and measuring method for shallow buried section of tunnel - Google Patents
Monitoring and measuring method for shallow buried section of tunnel Download PDFInfo
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- CN111998825A CN111998825A CN202010824273.3A CN202010824273A CN111998825A CN 111998825 A CN111998825 A CN 111998825A CN 202010824273 A CN202010824273 A CN 202010824273A CN 111998825 A CN111998825 A CN 111998825A
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- 238000012544 monitoring process Methods 0.000 title claims abstract description 53
- 238000000034 method Methods 0.000 title claims abstract description 28
- 238000005259 measurement Methods 0.000 claims abstract description 95
- 238000010276 construction Methods 0.000 claims abstract description 24
- 239000011435 rock Substances 0.000 claims abstract description 12
- 230000002159 abnormal effect Effects 0.000 claims abstract description 4
- 238000009434 installation Methods 0.000 claims abstract description 4
- 238000006073 displacement reaction Methods 0.000 claims description 30
- 238000009412 basement excavation Methods 0.000 claims description 29
- 239000012528 membrane Substances 0.000 claims description 21
- 238000005422 blasting Methods 0.000 claims description 7
- 239000004925 Acrylic resin Substances 0.000 claims description 3
- 229920000178 Acrylic resin Polymers 0.000 claims description 3
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical group [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 3
- 239000000853 adhesive Substances 0.000 claims description 3
- 230000001070 adhesive effect Effects 0.000 claims description 3
- 238000004458 analytical method Methods 0.000 claims description 3
- 239000004568 cement Substances 0.000 claims description 3
- 238000007405 data analysis Methods 0.000 claims description 3
- 238000013461 design Methods 0.000 claims description 3
- 230000035772 mutation Effects 0.000 claims description 3
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- 239000011378 shotcrete Substances 0.000 claims description 3
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- 230000000246 remedial effect Effects 0.000 description 2
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
- G01C5/00—Measuring height; Measuring distances transverse to line of sight; Levelling between separated points; Surveyors' levels
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
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Abstract
A monitoring and measuring method for a shallow tunnel segment relates to a monitoring and measuring method for a shallow tunnel segment during tunnel construction. The method is invented for mainly solving the problem that the traditional measurement method cannot find the deformation trend of the tunnel in advance. The observation points are arranged before the tunnel is excavated, the section of the tunnel mouth and the section with the buried depth less than two times of the width of the tunnel are arranged, and a measuring section is arranged at an interval of 5-10 m; when the geological condition is deteriorated or the measured value is abnormal, the measuring frequency is increased, and when the deformation is stable, the measuring frequency can be properly reduced. The general section of the arrangement of the convergence measuring lines adopts 2-3 measuring lines, but a horizontal measuring line is required at the arch springing position. The embedding of the measuring point meets the requirement of fast and close installation of the measuring instrument. The measuring points should be buried in the shallow layers of the surrounding rocks. The vault subsidence measurement and the horizontal clearance change measurement are carried out in the same measurement section. The method has the advantage that whether the tunnel section deforms or not is judged in advance under the condition that the tunnel section does not deform.
Description
The technical field is as follows:
the invention relates to a monitoring and measuring method for a shallow tunnel segment during tunnel construction.
Background art:
the shallow buried layer of the tunnel is thin in coverage, loose in stacking and poor in self stability. The construction method is easy to be influenced by dead weight, rainwater and construction blasting in the construction process, and large deformation accidents such as collapse, settlement and the like easily occur, so that the overall stability of the tunnel is threatened. After the tunnel is excavated, a stress disturbance area in a stratum of a shallow buried section of a tunnel opening extends to the earth surface, the change of the mechanical form of the surrounding rock is reflected to the earth surface settlement to a great extent, and the earth surface settlement can reflect the whole process of the deformation of the surrounding rock in the tunnel excavation process. Therefore, the surface subsidence must be strictly monitored and controlled to ensure the safety of construction.
At present, the monitoring and measurement in the tunnel construction generally adopts the mode of settlement and convergence observation in the hole for measurement, and during the construction of a shallow-buried section, the deformation of the tunnel generally causes cracks and even collapse on the ground, and then the deformation of the tunnel can be reflected into the hole. The traditional measuring method cannot find the deformation trend of the tunnel in advance, and the construction safety is easily influenced.
The invention content is as follows:
the invention aims to solve the technical problem of providing a monitoring and measuring method for a shallow buried section of a tunnel, which judges whether deformation occurs in the tunnel of the section or not in advance through the conditions of crack, collapse, displacement and the like of the ground surface above the tunnel under the condition that deformation does not occur in the tunnel.
The above object is achieved by:
in order to ensure the construction safety of the shallow buried section of the tunnel, the ground surface settlement monitoring is required. The observation points are laid before the tunnel is excavated and are arranged on the same section as the observation points in the tunnel. And meanwhile, carrying out in-and-out observation, vault crown sinking and clearance change monitoring measurement on the tunnel, and setting the settlement observation plate according to the roadbed standard. The point distribution principle is as follows: longitudinal spacing is as in the table below;
ho is the tunnel buried depth, H is the tunnel excavation height, and B is the tunnel excavation width.
The section spacing is determined according to the terrain conditions, the transverse spacing of the earth surface settlement observation points is 2-5 m,
the measuring points near the middle line of the tunnel are properly encrypted, and the range of the two sides of the middle line of the tunnel is not less than H0+ B. In the selected measuring section area, a datum point with better visual condition, convenient measurement and firmness is firstly arranged, and the position of the datum point is outside the ground surface settlement influence area. The ground measuring points are arranged on the axis and two sides of the tunnel, and each section measuring point is generally more than 7 at intervals of 2-5 m. And (3) burying a cement pile at a measuring point, measuring, paying off and positioning, measuring the elevation of the measuring point by using a level or a total station, and calculating the variation of the elevation. According to the settlement amount of the earth surface of all monitoring points in different observation periods, the settlement amount of adjacent periods is compared to obtain the change trend of the settlement of the earth surface, and corresponding early warning is made or the construction scheme is recommended to be modified through analysis and judgment.
When the building has special requirements for surface subsidence, the measuring distance should be properly encrypted, and the range is properly widened.
And meanwhile, selecting a main section in the transverse direction according to the actual situation, and arranging measuring points along the main section to know the transverse influence range of the surface subsidence. And assigning a specially-assigned person to observe the surface subsidence change, and when the data has mutation, suspending the construction in the tunnel immediately and taking reinforced support or other treatment measures.
Monitoring and measuring in the shallow buried section:
the in-hole monitoring project is added according to the actual construction process, and the specific contents are as follows:
a digital camera for observing inside and outside of the tunnel, and a total station for vault sinking, clearance change and ground surface sinking;
the monitoring measurement frequency is determined according to the change condition of the monitoring data, and generally, the measurement frequency and period of each section are as follows:
monitoring frequency determined by distance from excavation surface
Note: and B, tunnel excavation width.
A monitoring frequency determined by a displacement rate;
monitoring measurement implementation and requirements:
measuring the clearance change;
the relative displacement in the direction of the two-point connection of the tunnel inner wall surface is called peripheral convergence. The convergence value is the difference between the distances measured twice and can reflect the working state and the stress property of the cavern.
Designing measurement;
the design of the headroom variation measurement includes: instrument selection, section spacing, measurement frequency, measurement line arrangement and measurement point burying.
(1) Selecting an instrument: a total station is used.
(2) Measuring the section spacing: in general, a section of the tunnel mouth and a section of the buried depth smaller than two times of the width of the tunnel are separated by 5-10 m of measuring cross sections; the remaining segments may be specifically determined according to geological conditions. The distance between the measuring sections can be increased for the tunnel with good geological conditions and stable convergence value; for the tunnel with poor geological conditions, unstable convergence value for a long time and fast excavation progress, the distance of the measuring section can be reduced. The pile number of the specific measuring section can be properly adjusted according to the actual situation, and the interval arrangement of the tunnel measuring sections is arranged according to the requirements of the following table.
(3) Measuring frequency: generally, the measurement frequency is determined according to the following table by considering the displacement rate of the measurement line and the distance from the working surface. When the geological conditions are deteriorated or the measured value is abnormal, the measuring frequency is increased, and if necessary, the measurement is carried out once every 2 to 5 hours. When the deformation is stable, the measurement frequency can be appropriately reduced. When the deformation speeds of all measuring lines in the same section are different, the measuring line generating the maximum deformation speed is used for determining the measuring frequency of the full section.
Note: b is the tunnel width
(4) And arranging convergence measuring lines. The arrangement and the number of the measuring lines are related to geological conditions, excavation methods and displacement speed, the measuring lines can be generally arranged according to the following table, 2-3 measuring lines are adopted in general sections, and a horizontal measuring line is required to be arranged at the arch springing. If the displacement value is larger or the bias voltage is significant, the absolute displacement measurement can be performed at the same time. The horizontal clearance convergence, the vault subsidence, the ground subsidence (shallow buried section) and other monitoring necessary measuring items are arranged on the same section.
Measurement of clearance variation
(5) The measuring point is buried to meet the requirements of fast installation (reading initial reading within 24 hours after blasting) and close (about 2 meters from the tunnel face) of the measuring instrument. The measuring points should be buried in the shallow layers of the surrounding rocks. The reflective mark is embedded into the sprayed concrete under the condition of meeting the observation requirement, so that the damage of human and mechanical equipment is prevented, the loss and the damage are timely repaired, and the continuity of measured data is ensured.
(6) Determining a measurement period; and after the deformation amount is deformed to a certain value, according to data analysis and a regression curve, no observation is carried out again after a stable value is reached.
Reading and recording measurement data:
the reading of the measurement data requires the following matters:
(1) when measuring points, the measuring instrument and the thermometer must be placed in the hole for 30 minutes before measurement can be carried out, so that the temperature correction amount can be ensured to reach certain precision.
(2) Before measurement, whether the measuring point is damaged, loosened, bent or the like needs to be checked, and if the above situation occurs, remedial measures need to be researched.
(3) And (5) timely arranging the original records into formal records. For each measuring line in each measuring section, the arranged measuring data should include: original recording tables and actual measuring point layout diagrams; a graph of the change of the displacement along with time and the distance of an excavation surface; and (5) a graph of the change of the displacement speed and the displacement acceleration along with time and the distance of the excavation surface. And (4) compiling the daily records into a daily report, and carrying out data processing or regression analysis on the arranged chart in time to obtain the final displacement and the displacement change rule so as to guide construction.
And (3) measuring the total station in a non-contact manner:
a total station non-contact monitoring system is a measuring system which effectively and rapidly monitors the clearance deformation of a tunnel by combining airborne software and data processing software on the basis of a polar coordinate measuring system.
In order to meet the requirement of tunnel deformation monitoring, the precision of the total station can be selected to be within +/-2' of angle measurement precision, and the distance measurement precision is 2mm +2 multiplied by 10-6 The total station of (1). The reflection sheet used in cooperation with the total station is a reflection membrane with reflection performance, the reflection membrane is made of acrylic resin, the back of the reflection membrane is made of non-setting adhesive, the thickness of the reflection membrane is 0.28mm, the reflection membrane is silver gray, and the size of the reflection membrane is selected according to distance measurement. During monitoring, a membrane type retro-reflector is used as a measuring point target, and the target is adhered to the embedded part. The measuring method can adopt a free station or a fixed station.
Vault subsidence measurement:
for the stratum with shallow buried depth and low consolidation degree and the tunnel with horizontal layering, the measurement is more important than the convergence measurement, and the measurement data is to confirm the stability of surrounding rocks, judge the supporting effect and prevent vault collapse.
The level clearance change, vault dip measurement must be 12 hours after each excavation, at the latest not more than 24 hours, and the initial readings are taken before the next cycle of excavation.
The vault subsidence measurement and the horizontal clearance change measurement are carried out in the same measurement section. When the geological conditions are complicated and the subsidence or bias is obvious, the arch subsidence and the basement uplift should be measured in addition to the vault subsidence.
On the premise of avoiding the damage caused by blasting operation, the measuring points are buried as close to the working face as possible, the general distance is 5-10 m, the measuring points are firm and reliable and easy to protect and recognize, and the signboard is hung on the measuring section. The vault subsidence measurement back viewpoint must be buried on the stable rock surface and is linked with the hole and the inner and outer leveling points. And 1-3 measuring points are arranged on each section, the measuring points are arranged at the center of the vault and near the vault, and the monitoring starting point is arranged at the designed elevation position of the secondary lining.
The invention has the advantages that: through the method of shallow section earth's surface observation, can judge whether can appear deformation in this section tunnel through whether the earth's surface of tunnel top appears crack, collapse, displacement etc. condition in advance under the condition that does not take place deformation in the tunnel hole, in time formulate the counter-measure, prepare in advance, ensure construction safety.
The specific implementation mode is as follows:
in order to ensure the construction safety of the shallow buried section of the tunnel, the ground surface settlement monitoring is required. The observation points are laid before the tunnel is excavated and are arranged on the same section as the observation points in the tunnel. And meanwhile, carrying out in-and-out observation, vault crown sinking and clearance change monitoring measurement on the tunnel, and setting the settlement observation plate according to the roadbed standard. The point distribution principle is as follows: longitudinal spacing is as in the table below;
| tunnel buried depth and digging width and height | Longitudinal measuring point spacing (m) |
| 2B＜Ho≤2（B+H） | 15-30 |
| B＜Ho≤2B | 10-15 |
| Ho≤B | 5-10 |
Ho is the tunnel buried depth, H is the tunnel excavation height, and B is the tunnel excavation width.
The section spacing is determined according to the terrain conditions, the transverse spacing of the earth surface settlement observation points is 2-5 m,
the measuring points near the middle line of the tunnel are properly encrypted, and the range of the two sides of the middle line of the tunnel is not less than H0+ B. In the selected measuring section area, a datum point with better visual condition, convenient measurement and firmness is firstly arranged, and the position of the datum point is outside the ground surface settlement influence area. The ground measuring points are arranged on the axis and two sides of the tunnel, and each section measuring point is generally more than 7 at intervals of 2-5 m. And (3) burying a cement pile at a measuring point, measuring, paying off and positioning, measuring the elevation of the measuring point by using a level or a total station, and calculating the variation of the elevation. According to the settlement amount of the earth surface of all monitoring points in different observation periods, the settlement amount of adjacent periods is compared to obtain the change trend of the settlement of the earth surface, and corresponding early warning is made or the construction scheme is recommended to be modified through analysis and judgment.
When the building has special requirements for surface subsidence, the measuring distance should be properly encrypted, and the range is properly widened.
And meanwhile, selecting a main section in the transverse direction according to the actual situation, and arranging measuring points along the main section to know the transverse influence range of the surface subsidence. And assigning a specially-assigned person to observe the surface subsidence change, and when the data has mutation, suspending the construction in the tunnel immediately and taking reinforced support or other treatment measures.
Monitoring and measuring in the shallow buried section:
the in-hole monitoring project is added according to the actual construction process, and the specific contents are as follows:
a digital camera for observing inside and outside of the tunnel, and a total station for vault sinking, clearance change and ground surface sinking;
the monitoring measurement frequency is determined according to the change condition of the monitoring data, and generally, the measurement frequency and period of each section are as follows:
monitoring frequency determined by distance from excavation surface
| Monitoring distance (m) between section and excavation surface | Monitoring frequency |
| （0～1）B | 2 times/d |
| （1～2）B | 1 times/d |
| （2～5）B | 1/2-3 d |
| ＞5B | 1 time/7 d |
Note: and B, tunnel excavation width.
A monitoring frequency determined by a displacement rate;
| rate of displacement (mm/d) | Monitoring frequency |
| ≥5 | 2 times/d |
| 1～5 | 1 times/d |
| 0.5～1 | 1/2-3 d |
| 0.2～0.5 | 1 time/3 d |
| <0.2 | 1 time/7 d |
Monitoring measurement implementation and requirements:
measuring the clearance change;
the relative displacement in the direction of the two-point connection of the tunnel inner wall surface is called peripheral convergence. The convergence value is the difference between the distances measured twice and can reflect the working state and the stress property of the cavern.
Designing measurement;
the design of the headroom variation measurement includes: instrument selection, section spacing, measurement frequency, measurement line arrangement and measurement point burying.
(1) Selecting an instrument: a total station is used.
(2) Measuring the section spacing: in general, a section of the tunnel mouth and a section of the buried depth smaller than two times of the width of the tunnel are separated by 5-10 m of measuring cross sections; the remaining segments may be specifically determined according to geological conditions. The distance between the measuring sections can be increased for the tunnel with good geological conditions and stable convergence value; for the tunnel with poor geological conditions, unstable convergence value for a long time and fast excavation progress, the distance of the measuring section can be reduced. The pile number of the specific measuring section can be properly adjusted according to the actual situation, and the interval arrangement of the tunnel measuring sections is arranged according to the requirements of the following table.
| Grade of surrounding rock | Section spacing (m) |
| Ⅴ | 5 |
| Ⅳ | 10 |
| Ⅲ | 30～50 |
(3) Measuring frequency: generally, the measurement frequency is determined according to the following table by considering the displacement rate of the measurement line and the distance from the working surface. When the geological conditions are deteriorated or the measured value is abnormal, the measuring frequency is increased, and if necessary, the measurement is carried out once every 2 to 5 hours. When the deformation is stable, the measurement frequency can be appropriately reduced. When the deformation speeds of all measuring lines in the same section are different, the measuring line generating the maximum deformation speed is used for determining the measuring frequency of the full section.
| Speed of displacement (mm/d) | Monitoring distance (m) between section and excavation surface | Monitoring measurement frequency |
| ≥5 | （0～1）B | 2 times/d |
| 1～5 | （1～2）B | 1 times/d |
| 0.5～1 | （2～5）B | 1/2-3 d |
| 0.2～0.5 | 1 time/3 d | |
| ＜0.2 | ＞5B | 1 time/7 d |
Note: b is the tunnel width
(4) And arranging convergence measuring lines. The arrangement and the number of the measuring lines are related to geological conditions, excavation methods and displacement speed, the measuring lines can be generally arranged according to the following table, 2-3 measuring lines are adopted in general sections, and a horizontal measuring line is required to be arranged at the arch springing. If the displacement value is larger or the bias voltage is significant, the absolute displacement measurement can be performed at the same time. The horizontal clearance convergence, the vault subsidence, the ground subsidence (shallow buried section) and other monitoring necessary measuring items are arranged on the same section.
Measurement of clearance variation
| Construction method | General section | In special areas |
| Full section method | A horizontal measuring line | |
| Step method | One horizontal measuring line for each step | One horizontal measuring line and two oblique measuring lines in each step |
| Fractional excavation method | One horizontal measuring line for each part | On the CD method or CRD method, each part has one horizontal measuring line, two oblique measuring lines and the rest has one horizontal measuring line |
(5) The measuring point is buried to meet the requirements of fast installation (reading initial reading within 24 hours after blasting) and close (about 2 meters from the tunnel face) of the measuring instrument. The measuring points should be buried in the shallow layers of the surrounding rocks. The reflective mark is embedded into the sprayed concrete under the condition of meeting the observation requirement, so that the damage of human and mechanical equipment is prevented, the loss and the damage are timely repaired, and the continuity of measured data is ensured.
(6) Determining a measurement period; and after the deformation amount is deformed to a certain value, according to data analysis and a regression curve, no observation is carried out again after a stable value is reached.
Reading and recording measurement data:
the reading of the measurement data requires the following matters:
(1) when measuring points, the measuring instrument and the thermometer must be placed in the hole for 30 minutes before measurement can be carried out, so that the temperature correction amount can be ensured to reach certain precision.
(2) Before measurement, whether the measuring point is damaged, loosened, bent or the like needs to be checked, and if the above situation occurs, remedial measures need to be researched.
(3) And (5) timely arranging the original records into formal records. For each measuring line in each measuring section, the arranged measuring data should include: original recording tables and actual measuring point layout diagrams; a graph of the change of the displacement along with time and the distance of an excavation surface; and (5) a graph of the change of the displacement speed and the displacement acceleration along with time and the distance of the excavation surface. And (4) compiling the daily records into a daily report, and carrying out data processing or regression analysis on the arranged chart in time to obtain the final displacement and the displacement change rule so as to guide construction.
And (3) measuring the total station in a non-contact manner:
a total station non-contact monitoring system is a measuring system which effectively and rapidly monitors the clearance deformation of a tunnel by combining airborne software and data processing software on the basis of a polar coordinate measuring system.
In order to meet the requirement of tunnel deformation monitoring, the precision of the total station can be selected to be within +/-2' of angle measurement precision, and the distance measurement precision is 2mm +2 multiplied by 10-6 The total station of (1). The reflection sheet used in cooperation with the total station is a reflection membrane with reflection performance, the reflection membrane is made of acrylic resin, the back of the reflection membrane is made of non-setting adhesive, the thickness of the reflection membrane is 0.28mm, the reflection membrane is silver gray, and the size of the reflection membrane is selected according to distance measurement. During monitoring, a membrane type retro-reflector is used as a measuring point target, and the target is adhered to the embedded part. The measuring method can adopt a free station or a fixed station.
Vault subsidence measurement:
for the stratum with shallow buried depth and low consolidation degree and the tunnel with horizontal layering, the measurement is more important than the convergence measurement, and the measurement data is to confirm the stability of surrounding rocks, judge the supporting effect and prevent vault collapse.
The level clearance change, vault dip measurement must be 12 hours after each excavation, at the latest not more than 24 hours, and the initial readings are taken before the next cycle of excavation.
The vault subsidence measurement and the horizontal clearance change measurement are carried out in the same measurement section. When the geological conditions are complicated and the subsidence or bias is obvious, the arch subsidence and the basement uplift should be measured in addition to the vault subsidence.
On the premise of avoiding the damage caused by blasting operation, the measuring points are buried as close to the working face as possible, the general distance is 5-10 m, the measuring points are firm and reliable and easy to protect and recognize, and the signboard is hung on the measuring section. The vault subsidence measurement back viewpoint must be buried on the stable rock surface and is linked with the hole and the inner and outer leveling points. And 1-3 measuring points are arranged on each section, the measuring points are arranged at the center of the vault and near the vault, and the monitoring starting point is arranged at the designed elevation position of the secondary lining.
Claims (1)
1. The monitoring and measuring method for the shallow buried section of the tunnel is characterized by comprising the following steps: the observation points are laid before the tunnel is excavated and are arranged on the same section as the observation points in the tunnel; simultaneously, observing inside and outside the tunnel, vault crown sinking and clearance change monitoring and measuring are carried out on the tunnel;
the section spacing is determined according to the terrain conditions, the transverse spacing of the earth surface settlement observation points is 2-5 m,
measuring points near the center line of the tunnel are properly encrypted, and the ranges of two sides of the center line of the tunnel are not less than the buried depth of the tunnel and the excavation width of the tunnel; in the selected measuring section area, firstly, a datum point with better visual condition, convenient measurement and firmness is required to be arranged, and the position of the datum point is required to be outside the ground surface settlement influence area; the ground measuring points are arranged on the axis and two sides of the tunnel, each section measuring point is generally more than 7, and the distance is 2-5 m; the cement pile is buried in the measuring point, the measurement, the setting and the positioning are carried out, the elevation of the measuring point is measured by a level or a total station, and the variation of the elevation is calculated; according to the settlement amount of the earth surface of all monitoring points in different observation periods, the settlement amount of adjacent periods is compared to obtain the change trend of the settlement of the earth surface, and corresponding early warning or construction scheme modification is carried out through analysis and judgment;
when the building (structure) has special requirements for surface subsidence, the measurement distance should be properly encrypted, and the range is properly widened;
meanwhile, selecting a main section according to the actual situation in the transverse direction, and arranging measuring points along the main section to know the transverse influence range of the surface subsidence; assigning personnel to observe the surface settlement change, and when the data has mutation, suspending the construction in the tunnel immediately and taking reinforced support or other treatment measures;
monitoring and measuring in the shallow buried section:
the in-hole monitoring project is added according to the actual construction process, and the specific contents are as follows:
a digital camera for observing inside and outside of the tunnel, and a total station for vault sinking, clearance change and ground surface sinking;
measurement of clearance variation: the relative displacement in the direction of the two-point connecting line of the inner wall surface of the tunnel is called peripheral convergence; the convergence value is the difference between the distances measured twice and can reflect the working state and the stress property of the cavern;
designing measurement;
the design of the headroom variation measurement includes: instrument selection, section spacing, measurement frequency, measurement line arrangement and measurement point burying;
(1) selecting an instrument: adopting a total station;
(2) measuring the section spacing: in general, a section of the tunnel mouth and a section of the buried depth smaller than two times of the width of the tunnel are separated by 5-10 m of measuring cross sections; the other sections can be specifically determined according to geological conditions; the distance between the measuring sections can be increased for the tunnel with good geological conditions and stable convergence value; for the tunnel with poor geological conditions, unstable convergence value for a long time and fast excavation progress, the distance between the measuring sections can be reduced;
(3) measuring frequency: when the geological condition is deteriorated or the measured value is abnormal, the measuring frequency is increased, and if necessary, the measurement is carried out once every 2 to 5 hours; when the deformation is stable, the measuring frequency can be properly reduced; when the deformation speeds of all measuring lines in the same section are different, determining the measuring frequency of the full section by the measuring line generating the maximum deformation speed;
(4) convergent survey line arrangement: the arrangement and the number of measuring lines are related to geological conditions, excavation methods and displacement speed, 2-3 measuring lines are adopted in a general section, but a horizontal measuring line is required to be arranged at an arch foot; if the displacement value is larger or the bias voltage is significant, the absolute displacement measurement can be performed at the same time; monitoring necessary measurement items such as horizontal clearance convergence, vault subsidence, ground subsidence and the like are arranged on the same section;
(5) burying the measuring point to meet the requirements of fast installation (reading initial reading within 24 hours after blasting) and close (about 2 meters away from the tunnel face) of the measuring instrument; the measuring points are buried in shallow layers of surrounding rocks; under the condition that the reflective mark meets the observation requirement, the reflective mark is embedded into the sprayed concrete, so that the damage of human and mechanical equipment is prevented, the loss and the damage are timely buried, and the continuity of measured data is ensured;
(6) determining a measurement period; after the deformation amount is deformed to a certain value, according to data analysis and a regression curve, no observation is carried out again after a stable value is reached;
and (3) measuring the total station in a non-contact manner:
the total station non-contact monitoring system is a measuring system which is used for effectively and quickly monitoring the clearance deformation of a tunnel by combining airborne software and data processing software on the basis of a polar coordinate measuring system;
in order to meet the requirement of tunnel deformation monitoring, the precision of the total station can be selected to be within +/-2' of angle measurement precision, and the distance measurement precision is 2mm +2 multiplied by 10-6 The total station of (1); the reflecting sheet used in cooperation with the total station is a reflecting membrane with reflecting performance, the reflecting membrane is made of acrylic resin, the back of the reflecting membrane is made of non-setting adhesive, the thickness of the reflecting membrane is 0.28mm, the reflecting membrane is silver gray, and the size of the reflecting membrane is selected according to distance measurement; during monitoring, a membrane type retro reflector is used as a measuring point target, and the target is adhered to the embedded part; the measuring method can adopt a free station or a fixed station;
vault subsidence measurement:
the horizontal clearance change and vault subsidence measurement need to be carried out 12 hours after each excavation, and the latest time is not more than 24 hours, and initial readings are read before the next cycle of excavation;
the vault subsidence measurement and the horizontal clearance change measurement are carried out in the same measurement section, and when the geological conditions are complex and the subsidence amount or bias pressure is obvious, the arch waist subsidence and the basement uplift amount are measured besides the vault subsidence measurement;
on the premise of avoiding damage caused by blasting operation, the measuring points are buried as close to a working face as possible, the general distance is 5-10 m, the measuring points are firm, reliable and easy to protect and recognize, a signboard is hung on a measuring section, a viewpoint is buried on a stable rock surface after vault crown subsidence measurement and is connected with a tunnel, an inner leveling point and an outer leveling point, 1-3 measuring points are arranged on each section, the measuring points are arranged at the center of the vault and the vicinity of the vault crown, and a monitoring starting point is arranged at a designed elevation position of a secondary lining.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112902933A (en) * | 2021-01-21 | 2021-06-04 | 河北建设勘察研究院有限公司 | Tunnel structure deformation monitoring device and monitoring method |
| CN113431016A (en) * | 2021-07-30 | 2021-09-24 | 中铁二十三局集团有限公司 | Soft rock large deformation section tunnel shallow-buried underground surface-penetrating building surface monitoring method |
| CN113446030A (en) * | 2021-08-02 | 2021-09-28 | 深圳市广汇源水利建筑工程有限公司 | Construction method and monitoring system of V-type surrounding rock reinforced primary lining pressure tunnel |
| CN114060059A (en) * | 2021-11-15 | 2022-02-18 | 中铁十九局集团第六工程有限公司 | Construction method of tunnel bottom deformation monitoring device |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101086209A (en) * | 2007-07-23 | 2007-12-12 | 北京交通大学 | Shield tunneling and shallow tunneling combined construction method for building underground station |
| CN101598026A (en) * | 2009-06-29 | 2009-12-09 | 中铁二院工程集团有限责任公司 | Wear the preliminary bracing structure of speedway loess stratum large section tunnel under the shallow embedding |
| CN104697495A (en) * | 2015-03-03 | 2015-06-10 | 江西飞尚科技有限公司 | On-line monitoring method for settlement and convergence in building construction and operation periods |
| CN108036765A (en) * | 2017-11-22 | 2018-05-15 | 山东大学 | A kind of tunnel clearance convergence monitoring measurement system and method based on three base-line methods |
| CN111336987A (en) * | 2020-03-30 | 2020-06-26 | 浙江省交通运输科学研究院 | Method for determining embedding depth of vault settlement monitoring point in tunnel construction |
-
2020
- 2020-08-17 CN CN202010824273.3A patent/CN111998825B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101086209A (en) * | 2007-07-23 | 2007-12-12 | 北京交通大学 | Shield tunneling and shallow tunneling combined construction method for building underground station |
| CN101598026A (en) * | 2009-06-29 | 2009-12-09 | 中铁二院工程集团有限责任公司 | Wear the preliminary bracing structure of speedway loess stratum large section tunnel under the shallow embedding |
| CN104697495A (en) * | 2015-03-03 | 2015-06-10 | 江西飞尚科技有限公司 | On-line monitoring method for settlement and convergence in building construction and operation periods |
| CN108036765A (en) * | 2017-11-22 | 2018-05-15 | 山东大学 | A kind of tunnel clearance convergence monitoring measurement system and method based on three base-line methods |
| CN111336987A (en) * | 2020-03-30 | 2020-06-26 | 浙江省交通运输科学研究院 | Method for determining embedding depth of vault settlement monitoring point in tunnel construction |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112902933A (en) * | 2021-01-21 | 2021-06-04 | 河北建设勘察研究院有限公司 | Tunnel structure deformation monitoring device and monitoring method |
| CN113431016A (en) * | 2021-07-30 | 2021-09-24 | 中铁二十三局集团有限公司 | Soft rock large deformation section tunnel shallow-buried underground surface-penetrating building surface monitoring method |
| CN113446030A (en) * | 2021-08-02 | 2021-09-28 | 深圳市广汇源水利建筑工程有限公司 | Construction method and monitoring system of V-type surrounding rock reinforced primary lining pressure tunnel |
| CN114060059A (en) * | 2021-11-15 | 2022-02-18 | 中铁十九局集团第六工程有限公司 | Construction method of tunnel bottom deformation monitoring device |
| CN114411824A (en) * | 2021-12-24 | 2022-04-29 | 北京市水利规划设计研究院 | Safety monitoring system of utility tunnel structure |
| CN115235417A (en) * | 2022-03-31 | 2022-10-25 | 中国矿业大学(北京) | Monitoring point setting method based on angle between stacked tunnels |
| CN115235417B (en) * | 2022-03-31 | 2023-07-25 | 中国矿业大学(北京) | Monitoring point setting method based on angle between overlapped tunnels |
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