CN103438820A

CN103438820A - Borehole profile rock and soil mass layered deformation optical fiber measuring method

Info

Publication number: CN103438820A
Application number: CN2013103990920A
Authority: CN
Inventors: 施斌; 魏广庆; 朴春德; 童恒金; 卢毅; 席均; 孙义杰; 刘瑾
Original assignee: SUZHOU NANZEE SENSING TECHNOLOGY CO LTD; Nanjing University
Current assignee: SUZHOU NANZEE SENSING TECHNOLOGY CO LTD; Nanjing University
Priority date: 2013-09-05
Filing date: 2013-09-05
Publication date: 2013-12-11

Abstract

The invention discloses an optical fiber measurement method for layered deformation of rock and soil mass in a drilling section. The measurement point is selected, and the soil layer is recorded after drilling. After the hole is formed, the sensing optical fiber is lowered and the hole is backfilled. When the sensing optical fiber When the surrounding rock and soil are deformed, the sensing fiber will be deformed due to the wrapping force of the surrounding soil, and the strain distribution of the corresponding position of the borehole profile can be obtained by measuring the strain distribution of the sensing fiber through BOTDR/A and other technologies If the obtained strain is integrated at the corresponding position along the optical fiber, the deformation of each soil layer of the deep rock and soil can be obtained, so as to realize the distributed measurement of the layered deformation of the rock and soil in the drilling section. It is suitable for deformation monitoring of rock and soil such as land subsidence, ground subsidence, and mines.

Description

A kind of borehole sections Rock And Soil layering distortion optical fibre measuring method

Technical field

The present invention relates to a kind of deformation measurement method of Rock And Soil, specifically a kind of borehole sections Rock And Soil layering distortion optical fibre measuring method.

Background technology

The exploitation of subterranean resource often easily causes the Rock And Soil distortion, causes the disasters such as Earth cave, surface collapse.Tunnel and goaf that particularly coal mining forms, Rock And Soil on every side is stressed to change, and causes the problems such as soil layer distortion, top board come off.For the problems referred to above, adopting the distortion of each layer of Rock And Soil of boring observation channel measurement is one of Main Means adopted at present.Therefore select effective borehole sections Rock And Soil deformation measurement method to be even more important.

In existing soil deformation measuring technique, monitoring technology mainly contains synthetic aperture interferometer radar (INSAR), GPS (GPS) and measurement of the level etc. on a large scale, wherein the INSAR technology is a kind of new spatial earth observation technology, areal is adopted to the echoed signal of interferometric method document image and phase place, obtain ground surface three dimensional physical geometric properties, obtain interference image by the phase differential that contrasts two width SAR images, and then obtain the ground elevation data from interference fringe, thereby realize settlement monitoring.The GPS technology is to utilize artificial satellite to carry out the trilateration location to an area, and the ground elevation data of obtaining according to location realize settlement monitoring.Synthetic aperture interferometer radar (INSAR) can be realized interior in a big way settlement monitoring with GPS (GPS) monitoring technology, is mainly used in zonal settlement monitoring research.Monitoring technology mainly contains the methods such as traditional measurement of the level, base-rock marker and layering mark among a small circle.Measurement of the level claims again " geometric leveling ", is the method for the point-to-point transmission discrepancy in elevation on ground of measuring with spirit-leveling instrument and levelling pole, can in settlement monitoring more among a small circle, obtain higher monitoring accuracy.Base-rock marker and layering mark monitoring technology are by burying base-rock marker and layering mark underground, and monitoring be take each layer compression (expansions) that bedrock surface is leveling point and measured, thereby obtain deflection and the ground settlement of each soil layer.

INSAR, GPS in above-mentioned monitoring technology, measurement of the level can not be for Rock And Soil layering deformation measurement.Base-rock marker and layering mark can be realized the layering deformation measurement of each Rock And Soil, but this technology belongs to conventional port, measure, and have the deficiencies such as the difficulty of enforcement is large, data volume finite sum sensing density is lower.The present invention be directed to problem and difficult point that Rock And Soil layering deformation monitoring exists, a kind of borehole sections Rock And Soil layering distortion optical fibre measuring method of proposition.

Summary of the invention

The present invention seeks to: in order to overcome the existing deficiency for Rock And Soil layering distortion routine monitoring ways and means, propose a kind of borehole sections Rock And Soil layering distortion optical fibre measuring method.

For achieving the above object, the technical scheme of taking of the present invention is:

Step 1 is Completion of Drilling Hole: the State selective measurements point, and adopt rig to carry out full core drill and advance, form a boring;

Step 2 is optical fiber cable placed: after pore-forming, the distributed sensing optical fiber that adopts drilling rod to lead hammer with counterweight is sent in boring, described sending in process, and controlling the drilling rod rate of sinking is 0.1m/s-0.5m/s, and controls counterweight by wire rope and lead the hammer sinking; Described optical fiber is the optical fiber with the optical fiber of sheath or employing secondary encapsulation, sensing optical fiber is with to lead hammer fixing, the middle part of sensing optical fiber is wrapped in that to lead hammer upper, at the symmetria bilateralis position of leading hammer, forms " U " font loop, to optical fiber with lead bearing of tup section and carry out the pyrocondensation protection; Arrange two optical fiber in boring, wherein one is temperature correction optical fiber simultaneously; The diameter range of described boring is 130-200mm.

Step 3 is the sealing of hole coupling: after embedded fibers, employing is admixed bentonitic fine sand and is carried out the backfill sealing of hole, and described backfill sealing of hole step or replacement are adopted as uses high-mark cement interpolation fine aggregate and accelerating chemicals to advance segmenting slip casting, and every segment length is 2-3 rice; In the process of described backfill, sensing optical fiber is in stretching state; The tail optical fiber of head is carried out after welding being integrated in the chest that the drilling orifice place arranges and protected, set up the fixedly pulley of sensing optical fiber after backfill in aperture;

Step 4 is observation: during sensing optical fiber Rock And Soil deformation on every side, measure the Strain Distribution of sensing optical fiber by BOTDR/A or BOFDA, obtain the Strain Distribution situation of borehole sections relevant position, the integration that the strain of obtaining is carried out to relevant position along optical fiber draws the deformation of deep each soil layer of Rock And Soil.

The present invention compared with prior art, has following beneficial effect:

1) realize borehole sections Rock And Soil layering distortion distributed measurement, overcome conventional measurement techniques as base-rock marker and the discontinuous defect of layering mark measuring point;

2) adopted direct burial and earth material backfill boring method to be laid, can make optical fiber and surrounding soil compatible deformation, each layer of deformation of Measurement accuracy Rock And Soil;

3) the method can monitor the STRESS VARIATION value of each point on whole borehole sections, can realize accurately location to the soil layer that produces distortion in Rock And Soil;

4) borehole sections Rock And Soil layering distortion optical fibre measuring method adopts packaged fiber and light signal, can overcome the rugged surroundings such as measured zone humidity, acid, alkali, the temperature difference are large.

The accompanying drawing explanation

Accompanying drawing 1 is borehole sections direct burial distributed fiber optic sensing method schematic diagram

Accompanying drawing 2 is led the hammer schematic diagram for counterweight

Embodiment

Below in conjunction with accompanying drawing, the present invention is further described.

As shown in Figure 1, basic skills of the present invention is as follows:

Step 1 is Completion of Drilling Hole: at first select a measurement point, adopt rig to carry out full core drill and advance, form the hole of certain depth, the degree of depth of boring can, according to real needs, can reach rice up to a hundred while needing; The boring soil layer is edited and recorded simultaneously, edited and recorded in observation, better grasping the test effect of different soil; In accompanying drawing 1, with different pattern mean the to hole soil layer of both sides differing texture;

Step 2 is optical fiber cable placed: after pore-forming, the diameter range 130-200mm of boring, adopt drilling rod to lead the distributed sensing optical fiber 2 of hammering 1 into shape with counterweight and send in hole, arranges two above-mentioned various optical fiber of optical fiber in boring simultaneously, and wherein one is temperature correction optical fiber; Described sending in process, control the drilling rod rate of sinking and be about 0.1-0.5m/s, and control counterweight by wire rope and lead hammer 1; Prevent that drilling rod and counterweight from leading hammer 1 and disconnecting, cause drilling rod to destroy other optical cable for sensings.Sensing optical fiber 2 is with to lead hammer fixing, and the middle part of sensing optical fiber 2 is wrapped in that to lead hammer upper, at the symmetria bilateralis position of leading hammer, forms " U " font loop, to optical fiber with lead bearing of tup section and carry out the pyrocondensation protection.Described optical fiber is the optical fiber with the optical fiber of sheath or employing secondary encapsulation, as Metal Substrate strand optical cable for sensing, GFRP glass fibre reinforcement straining and sensing optical cable, the banded optical cable of Metal Substrate, armouring pine sleeving temperature optical cable for sensing etc., improving in varying degrees the performances such as anti-damage, initial strain and the homogeneity of optical fiber, permanance, compatibility of deformation, strain transfer, extruding flexing resistance and laying feasibility, meet borehole sections Rock And Soil layering deformation measurement demand.Described counterweight is led hammer 1 profile schematic diagram as shown in Figure 2; Especially adopt Metal Substrate strand optical cable for sensing and GFRP glass fibre reinforcement straining and sensing optical cable; Arrange two optical fiber in boring, wherein one is sensing optical fiber simultaneously, and one is temperature correction optical fiber, is all that Metal Substrate strand optical cable for sensing forms optical cable with sensing optical fiber with together with temperature correction optical fiber with the reinforcement of GFRP glass fibre reinforcement.Make constructing operation be easier to carry out.

Step 3 is the sealing of hole coupling: after embedded fibers, employing is admixed a small amount of bentonitic fine sand and is carried out the backfill sealing of hole, described backfill sealing of hole step is replaceable is that the use high-mark cement adds appropriate fine aggregate (as flour sand and flyash) and accelerating chemicals advances segmenting slip casting, be that described backfill sealing of hole and described accelerating chemicals slip casting are carried out in segmentation, every segment length is 2-3 rice; In the process of described backfill, sensing optical fiber 2 is in stretching state; The tail optical fiber of head is carried out after welding being integrated in the chest that the hell place arranges and protected, set up the fixedly pulley of sensing optical fiber 2 after backfill in aperture; Wherein, bentonitic content is 4%-6%;

Step 4 is observation: during sensing optical fiber 2 Rock And Soil deformation on every side, by BOTDR/A or BOFDA(Distributed Optical Fiber Sensing Techniques) measure the Strain Distribution of sensing optical fiber 2, obtain the Strain Distribution situation of borehole sections relevant position, the integration that the strain of obtaining is carried out to relevant position along optical fiber draws the deformation of deep each soil layer of Rock And Soil.

The above is only the preferred embodiment of the present invention; be noted that for those skilled in the art; under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims

1. optical fibre measuring method is out of shape in a borehole sections Rock And Soil layering, it is characterized in that: direct-burried laying optical fiber in boring, the backfill soil sample, utilize Rock And Soil parcel power to make sensing optical fiber (2) and Rock And Soil compatible deformation on every side, obtain the deformation of each soil layer of Rock And Soil of optical fiber relevant position by the Strain Distribution of measuring sensing optical fiber, realize borehole sections Rock And Soil layering distortion distributed measurement, the method comprises the steps:

1) Completion of Drilling Hole: the State selective measurements point, adopt rig to carry out full core drill and advance, form a boring;

2) optical fiber cable placed: after pore-forming, the distributed sensing optical fiber that adopts drilling rod to lead hammer (1) with counterweight is sent in boring, described sending in process, and controlling the drilling rod rate of sinking is 0.1m/s-0.5m/s, and controls counterweight by wire rope and lead hammer (1) sinking;

3) sealing of hole coupling: after embedded fibers, employing is admixed bentonitic fine sand and is carried out the backfill sealing of hole, and described backfill sealing of hole step or replacement are adopted as uses high-mark cement interpolation fine aggregate and accelerating chemicals to advance segmenting slip casting; Sensing optical fiber in the process of described backfill (2) is in stretching state; The tail optical fiber of head is carried out after welding being integrated in the chest that the drilling orifice place arranges and protected, set up the fixedly pulley of sensing optical fiber (2) after backfill in aperture;

4) observation: during sensing optical fiber (2) Rock And Soil deformation on every side, measure the Strain Distribution of sensing optical fiber (2) by BOTDR/A or BOFDA, obtain the Strain Distribution situation of borehole sections relevant position, the integration that the strain of obtaining is carried out to relevant position along optical fiber draws the deformation of deep each soil layer of Rock And Soil.

2. optical fibre measuring method is out of shape in borehole sections Rock And Soil layering according to claim 1; it is characterized in that: step 2); described optical fiber is the optical fiber with the optical fiber of sheath or employing secondary encapsulation; sensing optical fiber (2) is with to lead hammer fixing; the middle part of sensing optical fiber (2) is wrapped in leads on hammer; form " U " font loop at the symmetria bilateralis position of leading hammer, to optical fiber with lead bearing of tup section and carry out the pyrocondensation protection.

3. borehole sections Rock And Soil layering distortion optical fibre measuring method according to claim 1, is characterized in that: step 2), the diameter range of described boring is 130-200mm.

4. borehole sections Rock And Soil layering distortion optical fibre measuring method according to claim 1 is characterized in that arranging two optical fiber in boring simultaneously, and wherein one is sensing optical fiber, and one is temperature correction optical fiber.

5. optical fibre measuring method is out of shape in borehole sections Rock And Soil layering according to claim 1, it is characterized in that: step 3), sealing of hole after embedded fibers, alternately adopt and admix bentonitic fine sand and carry out the backfill sealing of hole and adopt high-mark cement to add fine aggregate and accelerating chemicals slip casting, be that described backfill sealing of hole and described accelerating chemicals slip casting are carried out in segmentation, every segment length is 2-3 rice.

6. optical fibre measuring method is out of shape in borehole sections Rock And Soil layering according to claim 4, it is characterized in that: in boring, arrange two optical fiber simultaneously, wherein one is sensing optical fiber, one is temperature correction optical fiber, is all that Metal Substrate strand optical cable for sensing forms optical cable with sensing optical fiber with together with temperature correction optical fiber with the reinforcement of GFRP glass fibre reinforcement.