Reinforced with slip casting freezing pipe and freeze the construction method that service channel suppresses frozen swell and melt settlement
Technical field
Freeze the construction method that service channel suppresses frozen swell and melt settlement the present invention relates to a kind of reinforced with slip casting freezing pipe.This work
Method mixes a certain amount of cement mortar to improve the physical mechanics property of the soil body by the way that freezing pipe is also served as into Grouting Pipe in the soil body
Matter, can suppress influence of the frozen swell and melt settlement to surrounding formation and buildings or structures during service channel consolidation by freezing.
Background technology
There is a wide range of soft layer in the nearly river such as Ningbo, Shanghai and Nanjing, Haiti area, soil strength is relatively low, water content compared with
It is high.During underground engineering construction, it is necessary to take into account collapse, the reinforcing work of many problems, wherein service channel such as water burst
Work is crucial.Engineering with artificial freezing method and soil cement method for strengthening are all in daily use in engineering, cut both ways.
Freezing process utilizes manual pipe jacking Refrigeration Technique, the water in stratum is build-up ice, natural ground is become frozen soil, increases
Its strength and stability, isolation underground water and underground engineering are contacted, under the protection of frost wall, to carry out underground engineering pick
Build construction.It has can form frozen soil wall under extremely complex engineering geology and hydrogeologic condition, not by supporting scope and
The limitation of supporting depth, there is strict water proofing property and nonstaining property.
But after engineering with artificial freezing method construction, surrounding formation is produced frost heave, thaw collapse phenomenon, for surrounding environment so that soil
Engineering properties and adjacent buildings be adversely affected, such as cause foundation instability, make close to buildings produce inclination, crack,
The accidents such as building collapse can be caused when serious, or underground utilities is occurred the adverse consequences such as destruction.
After service channel frozen construction terminates, typically stratum is controlled by the way of the frost free period tracking grouting filling soil body
Sedimentation, selected most dependence engineering experience at slip casting position, grouting amount only only in accordance with daily Ground Subsidence Monitoring, engineering it is controllable
Property it is poor, it is difficult to completely control soft soil layer work after thaw collapse;Due to thaw collapse influence the cycle it is longer, early stage slip casting it is not in place past
During metro operation is caused, line produces differential settlement up and down, causes serious potential safety hazard.
The mode for forming soil cement induration in soil at present uses slip casting method, deep-mixed pile and high-pressure rotary spraying method.
This engineering method uses slip casting method therein.
Slip casting method be by cementing material be configured to slurries and inject it is loose containing sand or aquifer water-bearing stratum, it is the rock stratum containing crack, molten
Hole, crushed zone make the construction method that it solidifies.Slurries are condensed after hardening, are played cementing, ponding, stratum is consolidated and is separated
Water source, to ensure smooth construction.
In actual underground engineering, to improve the validity of foundation stabilization, engineering with artificial freezing method is integrated sometimes and soil cement is reinforced
Method is carried out simultaneously.As during metro tunnel excavation, shield end is originated and received, the construction of service channel is often because of soil cement
Reinforce failure to go wrong, freezing process at this moment can be taken to carry out once supplement again and reinforced;Or risk is larger, strata condition running into
When complicated or surrounding buildings or structures require sedimentation very little, basement process first is carried out with soil cement method for strengthening, is being formed afterwards
Soil cement on the basis of carry out engineering with artificial freezing method construction again.
The content of the invention
Had the advantages that simultaneously using engineering with artificial freezing method and the progress ground reinforcement of soil cement method for strengthening very important:Soil cement is carried
The high physico-mechanical properties of ground, when carrying out engineering with artificial freezing method construction on this basis, the freeze-thaw damage of generation is suppressed etc..
The later stage is avoided because condition does not allow to cause slip casting not in place, not in time, causes soft soil layer UNICOM road with tunnel structure in fortune
Differential settlement, problems of crack are produced during battalion.
Freeze applying for service channel suppression frozen swell and melt settlement it is an object of the invention to provide a kind of reinforced with slip casting freezing pipe
Work method., can be by the control of stratum settlement amount in 5mm by using this engineering method, thaw collapse coverage is controlled in 24m or so.
The purpose of the present invention is achieved through the following technical solutions:
A kind of slip casting freezing pipe, it is characterised in that the slip casting freezing pipe is made up of Grouting Pipe I and feed pipe II, wherein slip casting
Pipe I is made up of 3~6 sections, and Section 1 pipe end is equipped with drill bit III, and a check valve IV is respectively arranged in pipe shaft both sides;Feed pipe II is by two
Steel pipe cross weld is made.
Described a kind of slip casting freezing pipe, it is characterised in that described Grouting Pipe I is the seamless steel of Φ 89 × 8mm, 20# low-carbons
Pipe, Section 1 length is 1m, and follow-up each section length is 1.5m.
Described a kind of slip casting freezing pipe, it is characterised in that described feed pipe II is that Φ 45 × 3mm, 20# low-carbons are seamless
On steel pipe, one of 2~8m of length of steel pipe, another length of steel pipe 0.5m, the one side for being welded on 2~8m steel pipes front end.
Reinforced using described slip casting freezing pipe and freeze the construction method that service channel suppresses frozen swell and melt settlement, it is characterised in that
Construction procedure is as follows:
Barrier in a, preparation of construction, cleaning tunnel, builds construction operation platform;Supply line is connected, to meet drilling
Freezing system and excavation construct power supply in construction, tunnel;Lay pipeline to Freezing Method for Cross-passage Construction working face, drilled for hole position and
Freeze operating to supply water and blowdown;Check cement quality, rig service behaviour and the intact degree of measuring equipment;
B, locating holes, take secondary hole opening technology, according to hole position position, deflection, depth;Rig is in place, from MD-60
Rig, control mode 2KN/m, thrust 17KN carries out hole position and is drilled with;
After c, perforate are finished, Grouting Pipe is pierced to pre-pouring grout hole position and carries out slip casting, Grouting Pipe is low from Φ 89 × 8mm, 20#
Carbon seamless steel pipe, Section 1 slip casting length of tube is 1m, and follow-up Grouting Pipe is using 1.5m as a section, head section Grouting Pipe pipe ends and pipe shaft peace
Check valve slip casting is filled, check valve opens pressure between 0.3~0.5MPa, according to projected depth slip casting section by section;
D, grouting parameter, for soft soil layer, cement grout proportioning selects 10%, for the service channel of normal buried depth
(buried depth≤20m), controls 0.4~0.5MPa of grouting pressure during slip casting, if service channel buried depth it is relatively deep (20m < buried depths≤
When 40m), grouting pressure is increased to 0.8~1.0Mpa, it is ensured that slurries diffusion is uniform, control slip casting radius is in 1.8m~2.0m;Note
The control of slurry amount is according to undisturbed soil space when boring procedure soil erosion amount, and slurries finally fill the space of undisturbed soil 50%~60%
Conveniently;
E, rotation Grouting Pipe, it is ensured that cement mortar is sufficiently mixed uniformly with soil, and slip casting is suppressed after finishing to Grouting Pipe, row
Except unnecessary slurries, then feed pipe is disposed to be used as follow-up freezing pipe in Grouting Pipe, and with sponge or foamed plastic plugging hole
Mouthful, leaked outside to prevent slurries;
F, mobile drill are to next hole position, and hole position is drilled with is drilled method, and repeat step b-e using interval, until all notes
Slurry hole slip casting is finished;
G, drilling sequences, are preferentially drilled with to contact channel bottom hole position, then to hole position at the top of service channel, finally
For service channel both sides hole position, service channel both sides hole position is drilled with can be while carry out;
H, do not make grouting hole and directly arrange freezing pipe, sequence of construction is:Locating holes and orifice tube installation → aperture are close
Seal apparatus installation → drilling → measurement → blind hole bottom → bulge test.
Refrigeration system is freezed in i, installation, arrangement thermometer hole, relief hole, connecting line, installs heat-preserving equipment, test instrumentation,
Dissolve calcium chloride and fluorine oiling is filled to unit;
J, treat to conserve 14 days after the completion of last hole slip casting, start frozen construction, keep minimum brine temp -28~-
30 DEG C, until design frozen region reinforces and completed.
Beneficial effect
This reinforced with slip casting freezing pipe freezes the construction method that service channel suppresses frozen swell and melt settlement, compared to existing work
Method, has the advantages that:
1st, it is workable all with current existing engineering machinery;
2nd, engineering with artificial freezing method further enhances the intensity of the soil body on the basis of soil cement method for strengthening, is added the soil body
Gu, the enhancing of impervious and self-stability ability;
3rd, service channel stratum sealing strengthens, and can effectively control seepage action of ground water, reduces high water head pressure influence, increase
Later stage excavates the security constructed;
4th, soil cement stratum consolidation can effectively suppress the thaw collapse of surrounding frozen ground and its to surrounding building, structures
Influence;
5th, cement soil improvement is carried out in advance, it is to avoid the later stage does not allow to cause slip casting not in place, not in time because of condition, causes
Soft soil layer UNICOM road produces differential settlement, problems of crack with tunnel structure during runing, and strengthens later stage supplement
Slip casting controllability and reduction slip casting cycle in later stage, cement usage amount can be saved, reduce engineering time and manpower, machine cost.
Brief description of the drawings
Fig. 1 is slip casting freezing pipe schematic diagram,
Fig. 2 be the reinforcing of service channel soil cement order and stabilization zone schematic diagram,
Reference:I-Grouting Pipe, II-feed pipe, III-drill bit, IV-check valve, V-service channel external boundary
VI-freeze hole position (43~54) VII-slip casting and freeze hole position (1~42) VIII-drilling sequences number (1~54).
Embodiment
Embodiment 1:A kind of slip casting freezing pipe
Ningbo Metro Connection Passage, it is plain fill, silty sand ground, silty clay from top to down that geology where it rises on ground
Layer, the stratum of shield crossing is mainly silty clay layer.Service channel buried depth 27.6m, reinforcing engineering uses soil cement reinforcing+water
Flat freezing process joint reinforcement.According to design requirement, service channel reinforcement depth is 8.5m.
1st, a kind of slip casting freezing pipe, length is 8.5m, it is characterised in that the slip casting freezing pipe is by Grouting Pipe I and feed pipe II
Composition, wherein Grouting Pipe I is made up of 6 sections, and Section 1 pipe end is equipped with drill bit III, and a check valve IV is respectively arranged in pipe shaft both sides;Feed flow
Pipe II is made up of two steel pipe cross welds.
2nd, described a kind of slip casting freezing pipe, it is characterised in that described Grouting Pipe I is that Φ 89 × 8mm, 20# low-carbons are seamless
Steel pipe, Section 1 length is 1m, and follow-up each section length is 1.5m.
3rd, described a kind of slip casting freezing pipe, it is characterised in that described feed pipe II be Φ 45 × 3mm, 20# low-carbons without
Stitch on steel pipe, one of length of steel pipe 8.0m, another length of steel pipe 0.5m, the one side for being welded on 8m steel pipes front end.
Embodiment 2:A kind of slip casting freezing pipe
No. 3 line service channels of Suzhou subway, it is plain fill, silty clay from top to down that geology where it rises on ground
Layer, flour sand alternation of bed, Extra-fine sand.The stratum of shield crossing is mainly fine sand layer.Service channel buried depth 15.2m, reinforcing engineering
+ horizontal freezing joint reinforcement is reinforced using soil cement.According to design requirement, service channel reinforcement depth is 4m.
A kind of slip casting freezing pipe, length is respectively 4m, it is characterised in that the slip casting freezing pipe is by Grouting Pipe I and feed pipe II
Composition, wherein Grouting Pipe I is made up of 3 sections, and Section 1 pipe end is equipped with drill bit III, and a check valve IV is respectively arranged in pipe shaft both sides;Feed flow
Pipe II is made up of two steel pipe cross welds.
2nd, described a kind of slip casting freezing pipe, it is characterised in that described Grouting Pipe I is that Φ 89 × 8mm, 20# low-carbons are seamless
Steel pipe, Section 1 length is 1m, and follow-up each length is 1.5m.
3rd, described a kind of slip casting freezing pipe, it is characterised in that described feed pipe II be Φ 45 × 3mm, 20# low-carbons without
Stitch on steel pipe, one of length of steel pipe 3.5m, another length of steel pipe 0.5m, the one side for being welded on 3.5m steel pipes front end.
Embodiment 3:A kind of slip casting freezing pipe
Ningbo subway service channel, it is plain fill from top to down that geology where it rises on ground, and silty clay layer, powder is thin
Layer of sand.The stratum of shield crossing is mainly fine sand layer.Service channel buried depth 21.8m, reinforcing engineering uses soil cement reinforcing+water
Flat freezing process joint reinforcement.According to design requirement, service channel reinforcement depth is 7m.
A kind of slip casting freezing pipe, length is respectively 7m, it is characterised in that the slip casting freezing pipe is by Grouting Pipe I and feed pipe II
Composition, wherein Grouting Pipe I is made up of 5 sections, and Section 1 pipe end is equipped with drill bit III, and a check valve IV is respectively arranged in pipe shaft both sides;Feed flow
Pipe II is made up of two steel pipe cross welds.
2nd, described a kind of slip casting freezing pipe, it is characterised in that described Grouting Pipe I is that Φ 89 × 8mm, 20# low-carbons are seamless
Steel pipe, Section 1 length is 1m, and follow-up each section length is 1.5m.
3rd, described a kind of slip casting freezing pipe, it is characterised in that described feed pipe II be Φ 45 × 3mm, 20# low-carbons without
Stitch on steel pipe, one of length of steel pipe 6.5m, another length of steel pipe 0.5m, the one side for being welded on 6.5m steel pipes front end.
Embodiment 4:A kind of reinforced with slip casting freezing pipe freezes the construction method that service channel suppresses frozen swell and melt settlement
Ningbo Metro Connection Passage, it is plain fill, silty sand ground, silty clay from top to down that geology where it rises on ground
Layer, the stratum of shield crossing is mainly silty clay layer.Service channel buried depth 27.6m, reinforcing engineering uses soil cement reinforcing+water
Flat freezing process joint reinforcement.According to design requirement, service channel reinforcement depth is 8.5m.
A kind of reinforced with slip casting freezing pipe freezes the construction method that service channel suppresses frozen swell and melt settlement, and its construction procedure is such as
Under:
1st, barrier in preparation of construction, cleaning tunnel, builds construction operation platform;Supply line is connected, to meet drilling
Freezing system and excavation construct power supply in construction, tunnel;Lay pipeline to Freezing Method for Cross-passage Construction working face, drilled for hole position and
Freeze operating to supply water and blowdown;Check cement quality, rig service behaviour and the intact degree of measuring equipment;
2nd, locating holes, perforate inclination angle and azimuth are determined with theodolite and compass, accurately make perforate hole position, direction,
And help to layout in tunnel two, using secondary hole opening technology, and verified with stringing method, control hole position direction;Rig is in place, selects
MD-60 rigs, adjustment rig position, control mode 2KN/m, thrust 17KN carries out No. 1 hole position and is drilled with;
3rd, Grouting Pipe is pierced to No. 1 hole position and carries out slip casting, Grouting Pipe selects Φ 89 × 8mm, 20# low-carbon seamless steel pipes, the
One section slip casting length of tube is 1m, and pipe end installs check valve slip casting, and check valve opens pressure between 0.3~0.5MPa, according to design
Depth 8.5m, follow-up each section slip casting pipe range 1.5m, section by section slip casting;
4th, cement grout proportioning selects 10%, and 0.8~1.0MPa of grouting pressure is controlled during slip casting, controls slip casting radius
In 2.0m, grouting amount control is according to undisturbed soil space when boring procedure soil erosion amount, and slurries finally fill undisturbed soil 50%
~60% space;
5th, Grouting Pipe is rotated, it is ensured that cement mortar is sufficiently mixed uniformly with soil, and slip casting is finished disposes feed pipe in Grouting Pipe
Used as follow-up freezing pipe, feed pipe uses Φ 45 × 3mm, 20# low-carbon seamless steel pipes, with sponge or foamed plastic plugging hole
Mouthful, leaked outside to prevent slurries;
6th, mobile drill is to No. 2 hole positions, and hole position, which is drilled with, drills that (detailed bored grouting order is shown in Fig. 2 institutes to method using interval
Show), repeat step 2-6 is completed until soil cement reinforcing area is constructed;
7th, drilling sequences, are preferentially drilled with to contact channel bottom hole position (hole number 1~hole number 17), then logical to getting in touch with
Hole position (hole number 18~hole number 34), is finally service channel both sides hole position (hole number 35~hole number 42), service channel two at the top of road
Side opening position is drilled with can be while carry out;
8th, freezing pipe is arranged, is designed, freezed between hole count 54, each hole position in service channel top and bottom according to freezing curtain
Away from 0.7m, each side hole position spacing 0.6m;Injected hole use is not done in hole number 43~hole number 54, is mounted directly freezing pipe;Construction
Sequentially it is:Examination is suppressed in locating holes and orifice tube installation → port seal installation → drilling → measurement → blind hole bottom →
Test.
9th, install and freeze refrigeration system, refrigeration system can be synchronously installed during bored grouting, save the time;Freezing Station
Interior equipment mainly includes II type Screw chillers of YSLGF300 2 (standby one), and its maximum cooling capacity is about 87500kcal/h,
Freeze unit motor general power 110kw;IS150-125-250 salt water circulating pumps 2 (1 standby), flow 200m3/h, lift
30m, motor general power 30kw;IS150-125-250 cooling water circulating pumps 1, flow 200m3/h, lift 30m, motor total work
Rate 30kw;Cooling tower 2, motor general power 6kw;Brine tank one, volume 6m3;Afterwards connecting line, install heat-preserving equipment with
Test instrumentation, salt water conduit tube and collection liquid distribution pipe use Φ 159 × 5mm seamless steel pipes, and Φ is selected in collection, liquid distribution pipe and goat's horn connection
1.5 " high-pressure rubber pipes;The cooling water pipe welded tubes of Φ 5 ";Freezing plate is processed with the pipes of Φ 1.5 ";Temperature is installed on refrigerator water inlet pipe and water outlet pipe
Sensor is spent, pressure, temperature sensor and control valve are installed going, on the Brine Pipe of loop, flow is installed in Brine Pipe outlet
Meter, liquid level sensor is installed in brine tank;Two, valve is installed between brine distributing ring and frigo, so as to control freezing device salt solution
Flow;Vent valve is installed in the eminence of saline line;Check valve is installed on the salt water conduit tube of outlet;Salt solution and clear water pipeline are pressure-resistant
Respectively 0.7Mpa and 0.3MPA;Treat all to install, dissolve calcium chloride and fluorine oiling is filled to unit, salt solution proportion is 1.26
~1.27;
10th, frozen construction is started after last injected hole is conserved 14 days, positive freeze-off time is 40 days, is kept minimum
- 30 DEG C~-28 DEG C of brine temp, is completed until frozen region is reinforced;Then excavate and freeze the stage into maintenance, keep salt water temperature
Degree is at -28 DEG C or so, until service channel main structure construction is finished.
Embodiment 5:A kind of reinforced with slip casting freezing pipe freezes the construction method that service channel suppresses frozen swell and melt settlement
No. 3 line service channels of Suzhou subway, it is plain fill, silty clay from top to down that geology where it rises on ground
Layer, flour sand alternation of bed, Extra-fine sand.The stratum of shield crossing is mainly fine sand layer.Service channel buried depth 15.2m, reinforcing engineering
+ horizontal freezing joint reinforcement is reinforced using soil cement.According to design requirement, service channel reinforcement depth is 4.0m.
A kind of reinforced with slip casting freezing pipe freezes the construction method that service channel suppresses frozen swell and melt settlement, and its construction procedure is such as
Under:
1st, barrier in preparation of construction, cleaning tunnel, builds construction operation platform;Supply line is connected, to meet drilling
Freezing system and excavation construct power supply in construction, tunnel;Lay pipeline to Freezing Method for Cross-passage Construction working face, drilled for hole position and
Freeze operating to supply water and blowdown;Check cement quality, rig service behaviour and the intact degree of measuring equipment;
2nd, locating holes, perforate inclination angle and azimuth are determined with theodolite and compass, accurately make perforate hole position, direction,
And help to layout in tunnel two, using secondary hole opening technology, and verified with stringing method, control hole position direction;Rig is in place, selects
MD-60 rigs, adjustment rig position, control mode 2KN/m, thrust 17KN carries out No. 1 hole position and is drilled with;
3rd, Grouting Pipe is pierced to No. 1 hole position and carries out slip casting, Grouting Pipe selects Φ 89 × 8mm, 20# low-carbon seamless steel pipes, the
One section slip casting length of tube is 1m, and pipe end installs check valve slip casting, and check valve opens pressure between 0.3~0.5MPa, according to design
Depth 4.0m, follow-up each section slip casting pipe range 1.5m, section by section slip casting;
4th, cement grout proportioning selects 10%, and 0.4~0.5MPa of grouting pressure is controlled during slip casting, controls slip casting radius
For 1.8m, grouting amount control is according to undisturbed soil space when boring procedure soil erosion amount, and slurries finally fill undisturbed soil 50%
~60% space;
5th, Grouting Pipe is rotated, it is ensured that cement mortar is sufficiently mixed uniformly with soil, and slip casting is finished disposes feed pipe in Grouting Pipe
Used as follow-up freezing pipe, feed pipe uses Φ 45 × 3mm, 20# low-carbon seamless steel pipes, with sponge or foamed plastic plugging hole
Mouthful, leaked outside to prevent slurries;
6th, mobile drill is to No. 2 hole positions, and hole position, which is drilled with, drills that (detailed bored grouting order is shown in Fig. 2 institutes to method using interval
Show), repeat step 2-6 is completed until soil cement reinforcing area is constructed;
7th, drilling sequences, are preferentially drilled with to contact channel bottom hole position (hole number 1~hole number 17), then logical to getting in touch with
Hole position (hole number 18~hole number 34), is finally service channel both sides hole position (hole number 35~hole number 42), service channel two at the top of road
Side opening position is drilled with can be while carry out;
8th, freezing pipe is arranged, is designed, freezed between hole count 54, each hole position in service channel top and bottom according to freezing curtain
Away from 0.7m, each side hole position spacing 0.6m;Injected hole use is not done in hole number 43~hole number 54, is mounted directly freezing pipe;Construction
Sequentially it is:Examination is suppressed in locating holes and orifice tube installation → port seal installation → drilling → measurement → blind hole bottom →
Test.
9th, install and freeze refrigeration system, refrigeration system can be synchronously installed during bored grouting, save the time;Freezing Station
Interior equipment mainly includes II type Screw chillers of YSLGF300 2 (standby one), and its maximum cooling capacity is about 84500kcal/h,
Freeze unit motor general power 110kw;IS150-125-250 salt water circulating pumps 2 (1 standby), flow 200m3/h, lift
30m, motor general power 30kw;IS150-125-250 cooling water circulating pumps 1, flow 200m3/h, lift 30m, motor total work
Rate 30kw;Cooling tower 2, motor general power 8kw;Brine tank one, volume 6m3;Afterwards connecting line, install heat-preserving equipment with
Test instrumentation, salt water conduit tube and collection liquid distribution pipe use Φ 159 × 5mm seamless steel pipes, and Φ is selected in collection, liquid distribution pipe and goat's horn connection
1.5 " high-pressure rubber pipes;The cooling water pipe welded tubes of Φ 5 ";Freezing plate is processed with the pipes of Φ 1.5 ";Temperature is installed on refrigerator water inlet pipe and water outlet pipe
Sensor is spent, pressure, temperature sensor and control valve are installed going, on the Brine Pipe of loop, flow is installed in Brine Pipe outlet
Meter, liquid level sensor is installed in brine tank;Two, valve is installed between brine distributing ring and frigo, so as to control freezing device salt solution
Flow;Vent valve is installed in the eminence of saline line;Check valve is installed on the salt water conduit tube of outlet;Salt solution and clear water pipeline are pressure-resistant
Respectively 0.7Mpa and 0.3MPA;Treat all to install, dissolve calcium chloride and fluorine oiling is filled to unit, from N46 refrigerators
Oil, R22 refrigerants, saline solution proportion is 1.27;
10th, frozen construction is started after last injected hole is conserved 14 days, positive freeze-off time is 40 days, is kept minimum
- 30 DEG C~-28 DEG C of brine temp, is completed until frozen region is reinforced;Then excavate and freeze the stage into maintenance, keep salt water temperature
Degree is at -28 DEG C or so, until service channel main structure construction is finished.
Embodiment 6:A kind of reinforced with slip casting freezing pipe freezes the construction method that service channel suppresses frozen swell and melt settlement
Ningbo subway service channel, it is plain fill from top to down that geology where it rises on ground, and silty clay layer, powder is thin
Layer of sand.The stratum of shield crossing is mainly fine sand layer.Service channel buried depth 21.8m, reinforcing engineering using soil cement reinforce+
Horizontal freezing joint reinforcement.According to design requirement, service channel reinforcement depth is 7m.
A kind of reinforced with slip casting freezing pipe freezes the construction method that service channel suppresses frozen swell and melt settlement, and its construction procedure is such as
Under:
1st, barrier in preparation of construction, cleaning tunnel, builds construction operation platform;Supply line is connected, to meet drilling
Freezing system and excavation construct power supply in construction, tunnel;Lay pipeline to Freezing Method for Cross-passage Construction working face, drilled for hole position and
Freeze operating to supply water and blowdown;Check cement quality, rig service behaviour and the intact degree of measuring equipment;
2nd, locating holes, perforate inclination angle and azimuth are determined with theodolite and compass, accurately make perforate hole position, direction,
And help to layout in tunnel two, using secondary hole opening technology, and verified with stringing method, control hole position direction;Rig is in place, selects
MD-60 rigs, adjustment rig position, control mode 2KN/m, thrust 17KN carries out No. 1 hole position and is drilled with;
3rd, Grouting Pipe is pierced to No. 1 hole position and carries out slip casting, Grouting Pipe selects Φ 89 × 8mm, 20# low-carbon seamless steel pipes, the
One section slip casting length of tube is 1m, and pipe end installs check valve slip casting, and check valve opens pressure between 0.3~0.5MPa, according to design
Depth 7.0m, follow-up each section slip casting length of tube is 1.5m, section by section slip casting;
4th, cement grout proportioning selects 10%, and 0.8~0.9MPa of grouting pressure is controlled during slip casting, controls slip casting radius
For 1.9m, grouting amount control is according to undisturbed soil space when boring procedure soil erosion amount, and slurries finally fill undisturbed soil 50%
~60% space;
5th, Grouting Pipe is rotated, it is ensured that cement mortar is sufficiently mixed uniformly with soil, and slip casting is finished disposes feed pipe in Grouting Pipe
Used as follow-up freezing pipe, feed pipe uses Φ 45 × 3mm, 20# low-carbon seamless steel pipes, with sponge or foamed plastic plugging hole
Mouthful, leaked outside to prevent slurries;
6th, mobile drill is to No. 2 hole positions, and hole position, which is drilled with, drills that (detailed bored grouting order is shown in Fig. 2 institutes to method using interval
Show), repeat step 2-6 is completed until soil cement reinforcing area is constructed;
7th, drilling sequences, are preferentially drilled with to contact channel bottom hole position (hole number 1~hole number 17), then logical to getting in touch with
Hole position (hole number 18~hole number 34), is finally service channel both sides hole position (hole number 35~hole number 42), service channel two at the top of road
Side opening position is drilled with can be while carry out;
8th, freezing pipe is arranged, is designed, freezed between hole count 54, each hole position in service channel top and bottom according to freezing curtain
Away from 0.7m, each side hole position spacing 0.6m;Injected hole use is not done in hole number 43~hole number 54, is mounted directly freezing pipe;Construction
Sequentially it is:Examination is suppressed in locating holes and orifice tube installation → port seal installation → drilling → measurement → blind hole bottom →
Test.
9th, install and freeze refrigeration system, refrigeration system can be synchronously installed during bored grouting, save the time;Freezing Station
Interior equipment mainly includes II type Screw chillers of YSLGF300 2 (standby one), and its maximum cooling capacity is about 84500kcal/h,
Freeze unit motor general power 110kw;IS150-125-250 salt water circulating pumps 2 (1 standby), flow 200m3/h, lift
30m, motor general power 30kw;IS150-125-250 cooling water circulating pumps 1, flow 200m3/h, lift 30m, motor total work
Rate 30kw;Cooling tower 2, motor general power 8kw;Brine tank one, volume 6m3;Afterwards connecting line, install heat-preserving equipment
With test instrumentation, salt water conduit tube and collection liquid distribution pipe use Φ 159 × 5mm seamless steel pipes, and collection, liquid distribution pipe and goat's horn connection are selected
The high-pressure rubber pipes of Φ 1.5 ";The cooling water pipe welded tubes of Φ 5 ";Freezing plate is processed with the pipes of Φ 1.5 ";Installed on refrigerator water inlet pipe and water outlet pipe
Temperature sensor, installs pressure, temperature sensor and control valve going, on the Brine Pipe of loop, stream is installed in Brine Pipe outlet
Gauge, liquid level sensor is installed in brine tank;Two, valve is installed between brine distributing ring and frigo, so as to control freezing device salt
Water-carrying capacity;Vent valve is installed in the eminence of saline line;Check valve is installed on the salt water conduit tube of outlet;Salt solution and clear water pipeline are resistance to
Pressure is respectively 0.7Mpa and 0.3MPA;Treat all to install, dissolve calcium chloride and fluorine oiling is filled to unit, freezed from N46
Machine oil, R22 refrigerants, saline solution proportion is 1.27;
10th, frozen construction is started after last injected hole is conserved 14 days, positive freeze-off time is 40 days, is kept minimum
- 30 DEG C~-28 DEG C of brine temp, is completed until frozen region is reinforced;Then excavate and freeze the stage into maintenance, keep salt water temperature
Degree is at -28 DEG C or so, until service channel main structure construction is finished.