CN212389325U - Device for monitoring tunnel excavation surface void - Google Patents
Device for monitoring tunnel excavation surface void Download PDFInfo
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- CN212389325U CN212389325U CN202020545149.9U CN202020545149U CN212389325U CN 212389325 U CN212389325 U CN 212389325U CN 202020545149 U CN202020545149 U CN 202020545149U CN 212389325 U CN212389325 U CN 212389325U
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Abstract
The utility model discloses a device for monitoring tunnel excavation earth's surface is vacated, the device includes PVC bellows two and the PVC double-walled bellows one in the drilling hole wall that set up in drilling hole wall two, it is equipped with a galvanized steel pipe and link up two bellows from top to bottom and flush with PVC double-walled bellows one bottom to be equipped with a circular discus in PVC double-walled bellows one and the common bottom surface of PVC double-walled bellows one, interval is equipped with multichannel circular foam circle about PVC double-walled bellows one; and a pointer is arranged at the top of the galvanized steel pipe. The utility model discloses can detect out in the tunnel excavation work progress in time, the problem of taking off the air appears between tunnel vault upper portion and the earth's surface crust layer. Soil erosion and water loss caused in the process of drainage and drainage in tunnel construction, and the monitoring can be carried out by the device in the process of forming a cavity on the upper part of the vault and gradually enlarging the cavity.
Description
Technical Field
The utility model relates to a device for monitoring tunnel excavation earth's surface is vacated belongs to hydraulic and hydroelectric engineering technical field.
Background
In the process of constructing subways in karst areas, the burial depth of a common tunnel is not large, underground water is abundant, and the water level burial depth is shallow. Backfill layers such as a small amount of broken stones are distributed below the concrete surface layer on the ground surface, pipe networks such as rain and sewage pipes exist below the ground surface, and the concrete surface layer and the broken stone layer on the lower portion form a hard shell layer on the ground surface. The tunnel vault rock mass and the earth surface crust layer are between red clay layers, and the red clay layers generally have the characteristics of large pore ratio, high clay content, hardness at the top and softness at the bottom, high possibility of softening when meeting water and the like. A typical stratigraphic structure encountered in tunnel construction in karst areas is shown in figure 1. During the tunnel underground excavation construction process, water seepage or water burst in the tunnel often causes water and soil loss at a rock-soil interface and forms a cavity, and funnel-shaped karst collapse can be formed along with the increase of time. However, the urban ground surface is generally a concrete pavement layer with a large thickness, and the larger the supporting strength is, the larger the threat to ground traffic caused by sudden collapse is.
At present, in the process of constructing subways in karst regions, two monitoring methods for ground surface void exist. A method for directly measuring monitoring points on the ground surface mainly includes the steps of burying measuring points (the length of a monitoring rod is generally 0.2-2 m) in a ground surface range corresponding to a contour line of a tunnel structure, reflecting the size of ground surface subsidence according to the size of an observed value of the ground surface measuring points, and indirectly reflecting whether the lower part has the problem of void settlement. The method has the problems that the ground surface crust layer is difficult to quickly reflect the fact that the lower part is hollow, the whole formed by the monitoring rod and the concrete surface layer is always in a stable state under the condition that a larger cavity is formed at the lower part, the monitoring time lag defect is large, and misjudgment is easily caused. The second method is to directly find out whether the lower part has a cavity through a geophysical prospecting means, such as an earthquake mapping method, a surface wave method and the like, reflect the defectiveness of the lower geologic body through tested physical properties and electrical parameters, and the geophysical prospecting method has the characteristics of economy and high efficiency, but has obvious disadvantages of multiple solutions of test results, effectiveness of test depth and the like, generally needs to be comprehensively judged by combining drilling means, and is difficult to quickly and directly reflect the problems.
Therefore, for the surface void problem in the subway construction process in the karst region, research needs to be carried out according to the generation mechanism of the surface void problem so as to solve the problem by adopting a new method.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a device for monitoring tunnel excavation earth's surface is vacated to overcome prior art's not enough.
The technical scheme of the utility model as follows:
a device for monitoring tunnel excavation earth surface void is arranged in a drill hole, the top of the drill hole is a drill hole wall II, the lower part of the drill hole wall I is a drill hole wall I with the inner diameter contracted, the device comprises a PVC double-wall corrugated pipe II arranged in the drill hole wall II and a PVC double-wall corrugated pipe I arranged in the drill hole wall I, a galvanized steel pipe is arranged at the central parts of the PVC double-wall corrugated pipe I and the PVC double-wall corrugated pipe II, the galvanized steel pipe penetrates through the two corrugated pipes from top to bottom and is flush with the bottom of the PVC double-wall corrugated pipe I, a round discus is arranged on the common bottom surface of the galvanized steel pipe and the PVC double-wall corrugated pipe I, and a plurality of round; and a pointer is arranged at the top of the galvanized steel pipe.
The utility model discloses in detecting out the tunnel excavation work progress with new means or device immediately, the problem of taking off appears between tunnel vault upper portion and the earth's surface crust layer. The water and soil loss caused in the process of drainage in tunnel construction is reduced, a cavity is formed at the upper part of the vault and is gradually enlarged (longitudinal development is main, transverse development is secondary), the device can be used for monitoring, the scale of the cavity can be judged according to the monitoring value, and then engineering treatment is guided. Therefore, whether the void layer and the size of the void layer are generated or not is monitored through the device, a strong guiding effect is achieved on the management of the void layer, and the device has important significance on guaranteeing the safety of tunnel construction and the safety of upper earth surface traffic.
Compared with the prior art, the utility model discloses following beneficial effect has: the utility model discloses device preparation and installation are simple, the cost of manufacture is low, convenient operation. The method can play a role in accurately monitoring the air separation caused by underground water and soil loss in the tunnel excavation in the construction period, and can carry out timely prejudgment on the air separation condition and guide the construction treatment. The utility model discloses a device provides one kind with lower input, through in good time monitoring, has guaranteed construction safety and all ring edge borders's safety, respond well.
Drawings
FIG. 1 is a schematic diagram of a structure of a karst tunnel excavation stratum;
FIG. 2 is a schematic view of the monitoring device of the present invention;
FIG. 3 is a view showing a portion A of FIG. 2;
FIG. 4 is a view showing a large scale of the area B in FIG. 2;
fig. 5 is an installation effect diagram of the monitoring device of the present invention.
The labels in the figures are: 1-galvanized steel pipe, 2-PVC double-wall corrugated pipe I, 3-drilling hole wall I, 4-coarse sand, 5-circular foam ring, 6-circular discus, 7-drilling hole wall II, 8-PVC double-wall corrugated pipe II, 9-graduated scale, 10-pointer, 11-hole steel cover plate, 12-corrugated pipe connector and 13-cement paste.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
Example 1:
1. basic principle and basic requirements:
in this embodiment, the faced geological conditions are as shown in fig. 1, the device structure of the present invention is as shown in fig. 2-4, and the installation effect is as shown in fig. 5. The utility model discloses a hug closely circular discus 6 in device bottom in the soil body of certain distance above rock soil boundary line or vault, the initial stage of soil erosion and water loss appears on vault upper portion, because circular discus 6 and upper portion galvanized steel pipe 1 have very big dead weight (whole ending two are the buoyancy of trompil structure in order to eliminate groundwater), the two wholly can move down by oneself under the action of gravity according to the lower part soil body condition of coming to the air in good time, and it moves down and measurationly to drive earth's surface pointer 10 in good time, PVC double-walled bellows one 2 is in balanced quiescent condition owing to receive the ascending side resistance of the soil body this moment.
If water and soil loss occurs at the upper part of the vault in the initial stage, the circular discus 6 is clamped by broken stones in the hole wall or soil body at the outer side and is in a failure state, the cavity at the lower part is gradually enlarged and continuously develops upwards along with the prolonging of time to cause the soil body at the upper part to fall off, the soil body falling off or sinking at the outer side of the hole wall transmits negative friction to the PVC double-wall corrugated pipe I2 through coarse sand 4, and the quantity of the convex patterns on the outer wall and the size of the convex patterns determine the size of the negative friction transmitted downwards. Under the superposition effect of the self weight of the first PVC double-wall corrugated pipe 2 and the negative frictional resistance, the first PVC double-wall corrugated pipe 2 is triggered to be separated, and the bottom end of the first PVC double-wall corrugated pipe 2 is positioned at the upper part of the circular discus 6 and has a relatively small diameter, so that the gravity and the negative frictional resistance are finally applied to the circular discus 6. As the force increases it will eventually cause the circular discus 6 to move downwards against the resistance and also to be reflected at the surface pointer 10.
The larger the distance between the round discus 6 and the boundary line or the vault of the rock soil is, the larger the measuring range is. But the need to consider whether the surface has the need to obtain a rapid response at the early stage of soil erosion, namely the problem of measurement sensitivity.
When the lower dead zone is larger, the pointer 10 is close to the range of the lowest measuring range of the graduated scale 9 (namely the measuring range is limited), at the moment, the pointer 10 can be detached, the galvanized steel pipe 1 with a short section can be continuously connected, and then the pointer 10 is connected at the top end, so that the measuring range can be increased.
2. The operation steps are as follows:
step one, selecting the arrangement position of monitoring points. Through the early-stage exploration result, a representative geological weak point is selected as a monitoring point in the earth surface range corresponding to the contour line of the tunnel structure, and the stratum at the lower part of the point has geological characteristics that the part between the vault of the tunnel and the hard shell layer of the earth surface is a red clay layer or the lowest point of a deep solution groove valley. In fig. 1 and 5, roman numerals in circles represent: i-concrete pavement layer, II-gravel base layer, III-plastic red clay, IV-soft plastic red clay, V-rock mass, VI-fissure development zone, VII-heading face advancing direction, VIII-framed empty zone, IX-soil body void zone, X-underground water subsurface corrosion zone, XI-underground water level line and XII-collapse funnel.
Step two: and drilling a pre-buried hole. And drilling from the earth surface, wherein the upper part of the vault is a red clay layer, and the final hole is 1-2 m above the vault, and the final hole is 0.5-1 m above the lowest point of the trough if the upper part of the vault is the lowest point of the deep dissolving trough. The hard shell layer adopts phi 150mm to form a second drilled hole wall 7, and the red clay layer adopts phi 130mm to form a first drilled hole wall 3. And a dry drilling mode is adopted in the red clay layer to ensure the stability of the hole wall and remove sediments at the bottom of the hole.
And step three, connecting the galvanized steel pipe 1 and the round discus 6, connecting in sections and putting the steel pipe to the bottom of the hole, so that the weight is kept and the verticality is good.
And step four, the lower port of the PVC double-wall corrugated pipe I2 penetrates through the galvanized steel pipe 1 and is inserted into the bottom of the hole in sections. The lapping mode is shown in figure 3, a small amount of glue is pasted at the position of the corrugated pipe connector 12 in the lapping process, the PVC double-wall corrugated pipe I2 is ensured not to be separated in the lowering process, and the soil body negative friction can be ensured to be disconnected in sections in the later use process.
And fifthly, backfilling coarse sand 4 between the outer wall of the PVC double-wall corrugated pipe I2 and the hole wall I3 of the drilled hole. The main function is to transmit the negative frictional resistance generated in the sinking process of the soil body outside the hole wall to the PVC double-wall corrugated pipe I2.
And step six, connecting the first PVC double-wall corrugated pipe 2 and the second PVC double-wall corrugated pipe 8, wherein the inner side of the second PVC double-wall corrugated pipe 8 is provided with a graduated scale 9. The buried depth of the PVC double-wall corrugated pipe II 8 is 0.5-1 m below the ground surface, the lower end part of the PVC double-wall corrugated pipe II is mainly positioned in a concrete surface layer or a roadbed layer with better bearing capacity, and the reducing part of the PVC double-wall corrugated pipe II 8 can be just clamped so as to ensure that the PVC double-wall corrugated pipe II 8 and the crust layer keep integrity and do not generate relative displacement.
And seventhly, backfilling cement paste 13 between the PVC double-wall corrugated pipe II 8 and the drill hole wall II 7, wherein the cement paste is mainly used for ensuring the integral connectivity of the double-wall corrugated pipe II 8 and the hard shell layer.
And step eight, enabling a plurality of hollow circular foam rings 5 to penetrate through the galvanized steel pipe 1 in a centering manner, and ensuring that the hollow circular foam rings are uniformly spaced by about 5m in the holes. The method mainly has the function of ensuring that the galvanized steel pipe 1 is vertical in the PVC double-wall corrugated pipe I2 so as to ensure the accuracy of a measuring result.
And step nine, connecting the pointer 10 with the galvanized steel pipe 1 through a screw thread, and reading the steel pipe by matching the direction of the two ends of the pointer with the graduated scale 9.
Step ten, covering the hole opening with a hole opening steel cover plate 11 and ensuring that the hole opening is well embedded on the road surface. The cover plate is primarily used to protect the aperture.
And step eleven, after the installation, carrying out regular reading in the construction period, and judging according to the numerical value condition so as to guide the construction treatment.
Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments or portions thereof without departing from the spirit and scope of the invention.
Claims (8)
1. The utility model provides a device for monitoring tunnel excavation earth's surface is vacated, sets up in drilling, and the drilling top is drilling pore wall two (7), and the lower part is drilling pore wall one (3) after the internal diameter shrink, its characterized in that: the device comprises a PVC double-wall corrugated pipe II (8) arranged in a drilling hole wall II (7) and a PVC double-wall corrugated pipe I (2) arranged in a drilling hole wall I (3), wherein a galvanized steel pipe (1) is arranged at the central parts of the PVC double-wall corrugated pipe I (2) and the PVC double-wall corrugated pipe II (8) and penetrates through the two corrugated pipes from top to bottom and is flush with the bottom of the PVC double-wall corrugated pipe I (2), a round discus (6) is arranged on the common bottom surface of the galvanized steel pipe (1) and the PVC double-wall corrugated pipe I (2), and a plurality of round foam rings (5) are arranged in the PVC double-wall corrugated pipe I (2) at intervals from top to bottom; and a pointer (10) is arranged at the top of the galvanized steel pipe (1).
2. The apparatus for monitoring the earth surface void of a tunnel excavation according to claim 1, characterized in that: coarse sand (4) is filled between the PVC double-wall corrugated pipe I (2) and the drill hole wall I (3).
3. The apparatus for monitoring the earth surface void of a tunnel excavation according to claim 1, characterized in that: and cement paste (13) is filled between the second PVC double-wall corrugated pipe (8) and the second drilled hole wall (7).
4. The apparatus for monitoring the earth surface void of a tunnel excavation according to claim 1, characterized in that: the circular foam ring (5) is a disc structure with a hole in the center and is transversely embedded in the PVC double-wall corrugated pipe I (2), and the galvanized steel pipe (1) penetrates through the hole of the circular foam ring (5).
5. The apparatus for monitoring the earth surface void of a tunnel excavation according to claim 1, characterized in that: and a graduated scale (9) is arranged on the inner side of the PVC double-wall corrugated pipe II (8).
6. The apparatus for monitoring the earth surface void of a tunnel excavation according to claim 5, characterized in that: the pointer (10) is connected to the top of the galvanized steel pipe (1) through a screw thread, and the directions of the two ends of the pointer are matched with the graduated scale (9) for reading.
7. The apparatus for monitoring the earth surface void of a tunnel excavation according to claim 1, characterized in that: an orifice steel cover plate (11) is arranged above the pointer (10) and used for covering the orifice.
8. The apparatus for monitoring the earth surface void of a tunnel excavation according to claim 1, characterized in that: the PVC double-wall corrugated pipe I (2) is formed by connecting a plurality of corrugated pipes up and down through a corrugated pipe connector (12).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020545149.9U CN212389325U (en) | 2020-04-14 | 2020-04-14 | Device for monitoring tunnel excavation surface void |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020545149.9U CN212389325U (en) | 2020-04-14 | 2020-04-14 | Device for monitoring tunnel excavation surface void |
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| CN212389325U true CN212389325U (en) | 2021-01-22 |
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| CN202020545149.9U Active CN212389325U (en) | 2020-04-14 | 2020-04-14 | Device for monitoring tunnel excavation surface void |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111364971A (en) * | 2020-04-14 | 2020-07-03 | 中国电建集团贵阳勘测设计研究院有限公司 | Device for monitoring tunnel excavation surface void and installation method |
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2020
- 2020-04-14 CN CN202020545149.9U patent/CN212389325U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111364971A (en) * | 2020-04-14 | 2020-07-03 | 中国电建集团贵阳勘测设计研究院有限公司 | Device for monitoring tunnel excavation surface void and installation method |
| CN111364971B (en) * | 2020-04-14 | 2023-11-21 | 中国电建集团贵阳勘测设计研究院有限公司 | Device for monitoring surface void of tunnel excavation and installation method |
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