CN215169989U

CN215169989U - Freezing system for reinforcing 60-meter-grade ultra-long distance communication channel by freezing method

Info

Publication number: CN215169989U
Application number: CN202120926075.8U
Authority: CN
Inventors: 杨平; 陈驰; 吴永哲; 刘欣; 刘红伟; 张婷; 黄日生; 牛文
Original assignee: Nanjing Forestry University; CCCC Tunnel Engineering Co Ltd
Current assignee: Nanjing Forestry University; CCCC Tunnel Engineering Co Ltd
Priority date: 2021-04-30
Filing date: 2021-04-30
Publication date: 2021-12-14
Anticipated expiration: 2031-04-30

Abstract

The utility model relates to a freezing system for reinforcing a 60-meter ultra-long distance communication channel by a freezing method, which comprises a double-pump station structure, a communication channel structure, freezing holes and an independent cooling system; and freezing pipes are arranged in the freezing holes, the middle parts of the connection channel structures are in cross lap joint for 5 meters, independent cooling systems are respectively arranged in the left and right tunnels, and the connection channel structures and the pump station structures are optimized to be favorable for arrangement of the freezing pipes, so that the engineering quantity is reduced. The system of the utility model can give full play to the advantages of the freezing method, and build a 60-meter ultra-long distance communication channel in the water-rich weak stratum, and has the advantages of small influence on the construction environment, reliable reinforcing and water-stopping effect, time-saving construction period and the like; the system is suitable for tunnel engineering with complex city surrounding environment and 60-meter ultra-long communication channels.

Description

Freezing system for reinforcing 60-meter-grade ultra-long distance communication channel by freezing method

Technical Field

The utility model discloses a belong to tunnel construction technical field, relate to a construction technology of rich water weak stratum overlength contact passageway, specifically be freezing the system of 60 meters level overlength contact passageway for freezing method reinforcement.

Background

The connection channel is also called as a bypass channel, is a connection channel arranged between two single line interval tunnels and is a main risk accumulation section in tunnel engineering construction in order to meet the requirements of safe evacuation and water leakage discharge between tunnel intervals. After the tunnel connection channel construction is introduced by the self-freezing method, the construction method has the advantages of high reinforcing strength, good water stopping performance and the like, is widely applied to connection channel construction of water-rich soft soil strata such as Shanghai, Nanjing, Suzhou and the like, is generally 10-15 m long, has gradually improved theory and is relatively mature in application technology. However, with the rapid development of urban underground engineering construction, the number of underground existing buildings and structures is increasing, and the number of communication channels constructed in a specific environment is increasing, so that new problems are emerging continuously, particularly, the construction of long-distance or even ultra-long-distance communication channels in a water-rich weak stratum is complicated due to long distance and poor stratum stability, and the existing buildings at the periphery are difficult to meet the construction requirements under the influence of various adverse factors, so that serious consequences can be caused. Therefore, a freezing system of the 60-meter ultra-long distance communication channel needs to be strengthened by a freezing method urgently, design and construction are reasonably carried out, and safe completion of the ultra-long distance communication channel is ensured.

SUMMERY OF THE UTILITY MODEL

The utility model provides a freezing system of 60 meters level extra long distance contact passageway is consolidated to freezing method, its aim at be in order to overcome the not enough of prior art, can safe and reliable ground construction extra long distance contact passageway rich in water, satisfy safe sparse and drainage demand, reduce all ring edge borders and influence, improve economic benefits, the utility model provides a freezing system of 60 meters level extra long distance contact passageway is consolidated to freezing method.

The technical solution of the utility model is as follows: a freezing system of a 60-meter-level ultra-long distance communication channel is reinforced by a freezing method, and the system comprises a double-pump-station structure 4, a communication channel 5, a frozen soil curtain 3, a freezing hole 6 and two independent cooling systems 7; wherein, two pump station structures 4 set up the pump station for the contact passageway is close to left and right line tunnel department, frozen soil curtain 3 is the forcipate, and left side line tunnel 1 freezes hole 6 with right side line tunnel 2 two-way to being equipped with, freeze and be equipped with in the hole 6 and freeze the pipe and at 5 middle part cross overlap joints of contact passageway, two independent cooling systems 7 set up respectively in left side line tunnel 1 and right side line tunnel 2.

The pump station sets up respectively in the contact passageway and is close to left side tunnel 1 and 2 sides of right side tunnel, and pump station is close to tunnel one side corner cut passivation, and the corner cut is 135.

The height of the arch top of the intermediate channel (5) of the communication channel 5 is reduced by 195mm, which is 1500mm, and the bottom of the channel is a flat bottom plate.

The freezing pipe is characterized in that the freezing pipe is a low-carbon steel pipe with the diameter of phi 108 multiplied by 10mm, 170-180 freezing pipes are arranged, and the long-distance freezing pipes are lapped in the middle of the communication channel (5) within the range of 5.0 m.

Temperature measuring holes 10 are arranged around the freezing holes 6, pressure relief holes 11 are arranged in unfrozen soil in the frozen soil curtain, and seamless steel pipes with the diameter of 89 x 8mm are adopted.

And 3 rings of steel pipe sheets are arranged on two sides of the communication channel 5.

And grouting holes 9 are arranged in the communication channel 5 and the pump station.

The utility model has the advantages that:

(1) through two pump station structures, control and set up two pump stations, frozen soil curtain is the pincerlike, compares and sets up single pump station in the middle of the contact reaches, is showing and has reduced frozen soil volume and frost heaving and melt heavy.

(2) The structural arrangement of the overlong communication channel is optimized, the height of the arch crown of the middle channel part of the communication channel is reduced, the bottom of the channel is changed into a flat bottom plate from an arc-shaped inverted bottom arch, the frozen soil amount of the overlong channel can be reduced, and the construction period and the engineering amount are reduced on the basis of keeping the structure and the function complete.

(3) The independent freezing stations are arranged on the left side and the right side, so that the refrigerating capacity is improved, meanwhile, the freezing holes are drilled on the two sides, the middle of the freezing holes is in lap joint, so that the freezing effect is improved, compared with the method that the freezing stations are arranged on one side for cooling, a small number of through holes are utilized on the other side for cooling, the refrigerating effect is good, and the freezing speed is high.

(4) The structure and the freezing scheme design of the ultra-long connecting channel are optimized, the advantages of a freezing method are fully exerted, the 60-meter ultra-long connecting channel can be safely and reliably constructed in a water-rich weak stratum, and the method has the advantages of small influence on the construction environment, reliable reinforcing and water stopping effects, construction period saving and the like; the system is suitable for tunnel engineering with complex city surrounding environment and 60-meter ultra-long communication channels.

Drawings

FIG. 1 is a schematic diagram of a freezing system for freezing a 60-meter ultra-long distance communication channel according to the present invention;

FIG. 2 is a cross-sectional view A-A of FIG. 1;

FIG. 3 is a sequence diagram of excavation and construction;

fig. 4 is a plan view of the grouting holes.

The system comprises a left tunnel, a right tunnel, a 3 freezing curtain, a 4 double-pump station structure, a 5 connecting channel structure, a 6 freezing hole, a 7 independent cooling system, 8 steel pipes, 9 grouting holes, 10 temperature measuring holes, 11 pressure relief holes, 12 a first stage, 13 a second stage, 14 a third stage, 15 a fourth stage and 16 a safety door.

Detailed Description

The freezing system for reinforcing the 60-meter-level ultra-long distance communication channel by a freezing method is characterized by comprising a double-pump-station structure, a communication channel structure, freezing holes and an independent cooling system; freezing pipes are arranged in the freezing holes and are in cross lap joint in the middle of the communication channel structure, and independent cooling systems are respectively arranged in the left tunnel and the right tunnel.

Preferably, the double-pump-station structure is respectively arranged at the position close to the left tunnel and the right tunnel, and the cut angle of one side of the pump station close to the tunnels is passivated, and the cut angle is 135 degrees.

Preferably, the arch top height of the middle channel part of the communication channel structure is adjusted to be 1500mm, and the bottom of the channel is changed from a circular arc inverted bottom arch to a flat bottom plate.

Preferably, the freezing holes are respectively drilled in a bidirectional opposite mode from the left line tunnel and the right line tunnel, and freezing pipes are arranged in the freezing holes and are lapped in the middle of the communication channel structure within the range of 5.0 m. Temperature measuring holes are arranged around the freezing holes, and pressure relief holes are arranged in the safety door.

Preferably, 3 rings of steel pipe pieces are arranged on two sides of the center of the communication channel structure, and grouting holes are formed in the communication channel structure and the double-pump station structure.

The method for reinforcing the freezing system of the 60-meter-level ultra-long distance communication channel by the freezing method comprises the following steps:

(1) adding steel pipe sheets: when the shield machine tunnels, the number of the two sides of the position where the communication channel needs to be arranged is increased from 1 ring of steel pipe sheets to 3 rings.

(2) Designing a horizontal freezing scheme: freezing design is carried out according to construction conditions and soil body properties, and comprises the steps of comparing and selecting a freezing wall structure form, determining the thickness and the average temperature of a freezing wall, arranging freezing holes, temperature measuring holes and pressure relief holes, setting a freezing period, checking and calculating the freezing wall, designing a refrigerating system, a prestressed support, a safety door, excavating a temporary support, monitoring and protecting the influence on the surrounding environment and the like.

(3) Construction preparation: installing a contact channel freezing station, introducing a power supply into the contact channel freezing station by a cable, laying a water inlet pipe and a water outlet pipe, laying a freezing construction site at the contact channel by a wood board with the thickness of 5cm, building a freezing hole construction scaffold by a phi 48 multiplied by 4 mm steel pipe according to the drilling requirements of freezing holes at different positions, and processing various processed pieces such as a freezing pipe, a hole opening pipe and the like.

(4) Freezing hole construction: and constructing an ultra-long nearly horizontal hole and an inclined hole according to the connection channel structure, and adopting a drilling machine with excellent performance. A special drill rod phi 108 multiplied by 10mm is adopted, and the horizontal azimuth angle and the elevation (depression) angle of the manhole are given to compensate the drilling deflection. And in the drilling process, the deviation amount is measured in real time and the deviation can be corrected by using the drill bit capable of correcting deviation. Each bore is provided with an orifice tube and an orifice sealing device is installed. And (3) calculating the square amount of the hole effluent in time after each drilling is finished, combining the change of surface subsidence monitoring data, grouting in time, wherein the grouting pressure is 0.2-0.4 MPa higher than the pumping pressure during normal drilling, the absolute pumping pressure cannot exceed 2.5MPa, and the instantaneous pumping pressure cannot exceed 2.8 MPa. And (3) performing orifice supplementary grouting 20 hours after the final hole, realizing double effects of 'filling grouting' and compaction grouting, and enabling the steel pipe, the soil layer and the slurry body to be in a relatively stable state. The mixture ratio is cement: water: bentonite = 400-500: 1000: 25 to 50. Simultaneously, a freezing and refrigerating system, a brine system and a monitoring system are installed, debugged and operated.

(5) Active freezing: JYSLGF300 with larger refrigerating capacity is adopted

The freezing machine set can be used for quickly freezing and making the frozen wall be coiled as soon as possible. The brine cooling is carried out according to an expected cooling curve, and the active freezing time is designed to be about 60 days. In the freezing process, the temperature and the flow of the brine are monitored every day, the temperature of a temperature measuring hole and the pressure of a pressure relief hole are measured, the operation parameters of a freezing system are adjusted according to the freezing monitoring condition, and the development conditions (average temperature and thickness) of a freezing wall are calculated. And cold pipes and heat-insulating layers are laid on the sides, close to the bell mouths, of the left and right tunnel pipe sheets. 4 pressure relief holes are arranged in the unfrozen soil in the frozen soil curtain, a seamless steel pipe with the diameter of phi 89 multiplied by 8mm is adopted,when the stratum is compressed due to frost heaving, partial soil body is discharged from the pressure relief hole, and if the water pressure in the hole is increased, the hole opening valve is opened to relieve pressure. The starting time of the left and right line refrigerating units is staggered by 10 days, and the liquid supply time of the freezing pipe at the water collecting well is correspondingly delayed so as to reduce frost heaving. And in the positive freezing process, a tunnel prestress support and an emergency protective door are installed.

(6) Excavating and constructing: when the designed positive freezing period is achieved, the calculated minimum effective thickness and average temperature of the freezing wall reach design values, the average temperature of the interface of the freezing wall and the tunnel segment is not higher than-5 ℃, the temperature difference of the salt water of the removing and returning loop is not more than 1.5 ℃, the temperature of the outer boundary of the freezing wall is lower than 0 ℃, the drilled exploration hole reaches the design temperature and flows sand in a wireless manner, the air tightness test is qualified after the protective door is installed, emergency material is stored in place, and other preparation work is ready, so that the tunnel segment can be pulled to be excavated. Because the distance of the communication channel is long, excavation and construction are carried out in sections. The connection channel is constructed firstly, and then 2 pump stations are constructed. And (3) excavating and constructing in sections, excavating and constructing a communication channel in the first stage, the second stage and the third stage, excavating and constructing a double pump station in the fourth stage, and changing the position of the safety door along with excavation. Trial excavation is carried out from the inside of the tunnel at one side, then excavation is carried out from the other end of the channel, after the designed section position is reached, the excavation face is temporarily blocked, the emergency protective door is moved towards the excavation direction, primary waterproof construction and secondary structure construction are carried out, and then the next section of excavation and construction are carried out. And strictly controlling the excavation step pitch during excavation, timely supporting the section steel and adding the wood back plate, spraying concrete and well performing temporary support. The connection among the working procedures is made, and the exposure time of the frozen wall is reduced.

(7) Structural grouting and natural thawing and sinking grouting: fill the slip casting behind the timely wall that carries on after the structure is accomplished, whole frozen soil curtain scope is evenly covered in the slip casting hole, increases the slip casting hole to weak departments such as the pump house outside, horn mouth internal angle, and the inside pre-buried slip casting hole of passageway and pump house structure is pre-buried slip casting pipe when excavation temporary support, and the degree of depth is behind the wooden back plate. And (3) performing lining wall back filling grouting within 3-7 days after freezing is stopped, wherein during grouting, the freezing hole sealing is required to be completed, and the strength of the lining concrete reaches more than 60% of the design strength. And naturally thawing after filling and grouting, performing freeze wall thaw settlement compensation grouting according to the stratum monitoring condition, and following the principle of multiple times, small quantity and uniformity. And finally cutting off the orifice pipe or the freezing pipe and plugging, wherein all the reserved tunnel steel pipe sheet bins are filled with micro-expansive C35 plain concrete.

The technical solution of the present invention will be further explained with reference to the accompanying drawings.

Example 1

A residential building and an office building are respectively arranged above the two tunnels of the No. 2 line of the rail transit in a certain city, and the pipelines are densely distributed. The center distance between the contact channel and the pump station tunnel is 68.01m, the contact channel belongs to an overlong contact channel in China, and the strata sequentially comprise from top to bottom: the sand-containing water-based concrete has the advantages of fine silt sand (2-4-5), silt sand inclusion (2-4), medium fine sand (2-5) and silty clay (3-1), and is poor in self-stability, high in water-rich property, high in water permeability, poor in geological conditions and large in influence on construction. And (3) reinforcing the soil body by adopting a freezing method and constructing by adopting a mine underground excavation method.

The engineering adopts a freezing method to reinforce a freezing system of a 60-meter-level ultra-long distance communication channel, and the specific technical scheme is as follows:

a. and (4) adding steel pipe sheets, wherein when the shield tunneling machine tunnels, the number of the steel pipe sheets on two sides of the position where the communication channel is arranged is increased from 1 ring to 3 rings.

b. The horizontal freezing scheme is designed, freezing design is carried out according to construction conditions and soil body properties, double pump stations are arranged at the positions, close to left and right tunnels, of a communication channel through scheme selection, the thickness of a frozen soil curtain is designed to be 2.1m, the average temperature is less than or equal to minus 10 ℃, the active freezing time is 60 days, the number of freezing holes is 170 in total, the specification of freezing pipes is phi 108 multiplied by 10mm, the minimum design temperature of salt water is less than or equal to minus 28 ℃, the number of temperature measuring holes is 20, the number of pressure relief holes is 4, and 8 JYSLGF300 machines are adopted

The construction period of the refrigerator is 180 d.

c. Construction preparation, installation of an interconnection channel freezing station, introduction of a power supply into the interconnection channel freezing station by a cable, laying of water inlet and outlet pipes with an electric load of about 1400kVA and a water amount of 15m³H is used as the reference value. Paving a freezing construction site at the position of the communication channel by using a wood board with the thickness of 5cmAnd (3) drilling the freezing hole at the same position, constructing a freezing hole construction scaffold by using a phi 48 multiplied by 4 mm steel pipe, and processing a drill bit combination, the freezing pipe (also used as a drill rod), an orifice pipe, a plug, a brine tank, a tunnel prestressed support and the like.

d. Freezing hole construction, the construction process is: positioning the hole and the orifice tube mounting → mounting the orifice device → drilling → closing the bottom of the hole → pressing the test. The hole opening position error of the freezing hole is not more than 100mm, and a segment joint, a bolt, a main rib and a steel tube rib plate are avoided. The maximum allowable deviation of the freezing hole is 250 mm. And constructing the ultra-long near-horizontal hole and the inclined hole according to the connection channel structure, and constructing the ultra-long near-horizontal hole and the inclined hole according to the connection channel structure by adopting a drilling machine with excellent performance. A special drill rod with diameter of 108 multiplied by 10mm is adopted, the drill rod is completely processed into an inner wire, and the inner pipe hoop of a screw thread is adopted for connection and then welding. The manway horizontal azimuth and elevation (dip) angles are given to compensate for drilling deflection. And in the drilling process, the deviation amount is measured in real time and the deviation can be corrected by using the drill bit capable of correcting deviation. Each bore is provided with an orifice tube and an orifice sealing device is installed. Each bore is provided with an orifice tube and an orifice sealing device is installed. And (3) calculating the square amount of the hole effluent in time after each drilling is finished, combining the change of surface subsidence monitoring data, grouting in time, wherein the grouting pressure is 0.2-0.4 MPa higher than the pumping pressure during normal drilling, the absolute pumping pressure cannot exceed 2.5MPa, and the instantaneous pumping pressure cannot exceed 2.8 MPa. And (3) performing orifice supplementary grouting 20 hours after the final hole, realizing double effects of 'filling grouting' and compaction grouting, and enabling the steel pipe, the soil layer and the slurry body to be in a relatively stable state. The mixture ratio is cement: water: bentonite = 400-500: 1000: 25 to 50. Simultaneously, a freezing and refrigerating system, a brine system and a monitoring system are installed, debugged and operated. The engineering needs to arrange a machine room freezing station on the left and right lines respectively, wherein the floor area of the machine room freezing station is about 300 square meters, and the equipment in the station mainly comprises a refrigerator, a brine tank and a brine pump. The clean water pump and the cooling tower are arranged at the end well. And maintaining and painting construction after all equipment in the machine room is overhauled. And an on-duty room is arranged in the machine room. The brine pipeline is insulated by adopting a foam insulation material with the thickness of 50 mm. The specific gravity of the brine (calcium chloride solution) is 1.25-1.26, the system pipeline is filled with clear water, the brine tank is filled with half of the clear water, calcium chloride is dissolved in the brine tank (with a filtering device), a brine pump is started, and the calcium chloride is dissolved while circulating until the brine concentration reaches the design requirement. The unit firstly carries out leakage detection and nitrogen flushing on a refrigerating system, and then vacuumizes, fills fluorine and refuels after ensuring that the system has no leakage.

e. Active freezing: JYSLGF300 with larger refrigerating capacity is adopted

The freezing machine set can be used for quickly freezing and making the frozen wall be coiled as soon as possible. And (3) carrying out brine cooling according to an expected cooling curve, designing active freezing time to be about 60 days, carrying out single-hole flow rate of no less than 5 m/h, carrying out active freezing for 7 days, reducing the brine temperature to below-18 ℃, carrying out active freezing for 15 days, reducing the brine temperature to below-24 ℃, and reducing the brine temperature to below-28 ℃ during excavation. In the freezing process, the temperature and the flow of the brine are monitored every day, the temperature of a temperature measuring hole and the pressure of a pressure relief hole are measured, the operation parameters of a freezing system are adjusted according to the freezing monitoring condition, and the development conditions (average temperature and thickness) of a freezing wall are calculated. The temperature monitoring adopts an electronic temperature measuring system, thermocouple sensors are arranged on the brine main pipes of the return and return circuits and each group of freezing pipes to measure the temperature of brine, the thermocouple sensors are arranged in temperature measuring holes to measure the temperature of soil, and data are automatically measured and recorded by the system. And cold pipes and heat-insulating layers are laid on the sides, close to the bell mouths, of the left and right tunnel pipe sheets. 4 pressure relief holes (the hole depth is 30m) are arranged in unfrozen soil in the frozen soil curtain, a seamless steel pipe with the diameter of 89 multiplied by 8mm is adopted, when stratum compression is caused by frost heaving, partial soil body is discharged from the pressure relief holes, and if the water pressure in the holes is increased, the hole opening valve is opened to relieve the pressure. The starting time of the left and right line refrigerating units is staggered by 10 days, and the liquid supply time of the freezing pipe at the water collecting well is correspondingly delayed so as to reduce frost heaving. And in the positive freezing process, a tunnel prestress support and an emergency protective door are installed. 4 prestressed supports are arranged in the connection channel, two side frames are arranged at the two sides of the opening of the connection channel of the interval tunnel at the interval of 2m, the prestressed supports are symmetrically arranged at the two ends of the connection channel along the tunnel direction, the installation time is not later than 15 days after starting and freezing, and the prestressed supports are required to be arranged before freezing the curtain loops.

f. Excavating and constructing: when the designed positive freezing period is achieved, the calculated minimum effective thickness and average temperature of the freezing wall reach design values, the average temperature of the interface of the freezing wall and the tunnel segment is not higher than-5 ℃, the temperature difference of the salt water of the removing and returning loop is not more than 1.5 ℃, the temperature of the outer boundary of the freezing wall is lower than 0 ℃, the drilled exploration hole reaches the design temperature and flows sand in a wireless manner, the air tightness test is qualified after the protective door is installed, emergency material is stored in place, and other preparation work is ready, so that the tunnel segment can be pulled to be excavated. Because the contact passageway distance is long, need occupy the contact passageway simultaneously and control the line tunnel, set up work platform at the contact passageway opening part, utilize the tunnel as row's sediment and material transport passageway. And excavating and constructing in sections. The connection channel is constructed firstly, and then 2 pump stations are constructed. The excavation and construction are divided into 4 sections (see fig. 4), specifically: in the first stage, two ends are excavated simultaneously, and earth excavation, concrete spraying, water prevention, reinforcing steel bar pouring and concrete pouring before the first construction joint are finished (in the process, excavation of a drainage ditch and laying of a drainage pipe are required to be finished); before the second stage is started, the safety protection door is required to be moved to the annular embedded channel steel embedded in the structure, the protection door is installed, and after the protection door is installed, earth excavation, concrete spraying, water proofing, reinforcing steel bars and concrete pouring of the second stage are started; before the third stage begins, the safety protection door needs to be moved to the annular embedded channel steel embedded in the structure, the protection door is installed, and after the protection door is installed, earthwork excavation, concrete spraying, water prevention, steel bar pouring and concrete pouring of the third stage begin. And finishing the excavation of the channel part and the second lining construction. And (4) excavating a water collecting well in a fourth stage, wherein earthwork excavation, concrete spraying, water prevention, steel bar pouring and concrete pouring are required to be completed in the fourth stage. And excavating the water collecting well in the fourth stage, wherein the water collecting well is completely frozen when being excavated, and full-section layer-by-layer excavation can be carried out. And after the excavation is finished, carrying out supporting and guniting construction, and then carrying out waterproof and secondary lining construction. During excavation, the excavation step pitch is strictly controlled, an air pick, a shovel and a hand pick are combined, manual soil discharging is carried out, soil discharging on a working face is carried out by adopting an agricultural tricycle, the agricultural tricycle is pushed into a special soil discharging box near a well mouth, and the soil is discharged to the ground by using a gantry crane.

g. Structural grouting and natural thawing and sinking grouting: and (3) filling grouting after lining is carried out within 3-7 days after the completion of the secondary lining of each stage, grouting holes uniformly cover the range of the whole frozen soil curtain, grouting holes are added at weak positions such as the outer side of the pump house, the inner angle of a horn mouth and the like, grouting holes are pre-buried in the channel and the pump house structure, grouting pipes are pre-buried when the temporary support is excavated, and the depth reaches the back of the wood back plate. The filling grouting adopts single-liquid cement slurry, the thawing grouting adopts single-liquid cement slurry, the grade strength of the single-liquid cement slurry is Po.42.5 grade, the water cement ratio is generally 0.8, the grouting equipment adopts an SYB 50-45II hydraulic grouting pump, the grouting pressure at the water collecting well is not more than 0.1MPa, the grouting pressure at the channel part is not more than hydrostatic pressure, the grouting is preferably carried out from bottom to top, and the next layer of grouting can be stopped after the continuous slurry return of the grouting hole at the upper layer until the grouting to the vault is finished. And (3) performing lining wall back filling grouting within 3-7 days after freezing is stopped, wherein during grouting, the freezing hole sealing is required to be completed, and the strength of the lining concrete reaches more than 60% of the design strength. And (3) adopting a natural thawing method, starting to perform thaw precipitation grouting 1 month after freezing is stopped, performing freeze wall thaw precipitation compensation grouting according to stratum monitoring conditions, and following the principle of multiple times, small amount and uniformity. And finally cutting off the orifice pipe or the freezing pipe and plugging, wherein all the reserved tunnel steel pipe sheet bins are filled with micro-expansive C35 plain concrete.

Claims

1. A freezing system for reinforcing a 60-meter-level ultra-long distance communication channel by a freezing method is characterized by comprising a double-pump-station structure (4), a communication channel (5), a frozen soil curtain (3), a freezing hole (6) and two independent cooling systems (7); wherein, two pump station structures (4) are close to two pump stations that left and right side line tunnel department set up in the contact passageway, frozen soil curtain (3) are the pincerlike, and left side line tunnel (1) and right side line tunnel (2) are two-way to being equipped with freezing hole (6), freezing and being equipped with in hole (6) and freezing the pipe and at contact passageway (5) middle part cross overlap joint, two independent cooling system (7) set up respectively in left side line tunnel (1) and right side line tunnel (2).

2. The freezing system for freezing and reinforcing the 60-meter-scale ultra-long distance communication channel by the freezing method according to claim 1, wherein the pump stations are respectively arranged on the sides of the communication channel, which are close to the left tunnel (1) and the right tunnel (2), and the chamfer angles of the sides of the pump stations, which are close to the tunnels, are passivated and are 135 degrees.

3. The freezing system for reinforcing a 60-meter ultra-long distance communication channel by a freezing method according to claim 1, wherein the arch height of the middle channel of the communication channel (5) is 1500mm, and the bottom of the channel is a flat bottom plate.

4. The freezing system for freezing and reinforcing the 60-meter-scale ultra-long distance communication channel by the freezing method according to claim 1, wherein the freezing pipes are phi 108 x 10mm low-carbon steel pipes, 170-180 freezing pipes are arranged, and the long distance freezing pipes are lapped in the middle of the communication channel (5) within 5.0 m.

5. The freezing system for reinforcing the 60-meter-scale ultra-long distance communication channel by the freezing method according to claim 1, wherein temperature measuring holes (10) are arranged around the freezing holes (6), pressure relief holes (11) are arranged in unfrozen soil in a frozen soil curtain, and seamless steel pipes with the diameter of 89 x 8mm are adopted.

6. The freezing system for freezing and reinforcing the 60-meter-scale ultra-long distance communication channel by the freezing method according to claim 1, wherein 3-ring steel pipe sheets are arranged on two sides of the communication channel (5).

7. The freezing system for reinforcing the 60-meter-scale ultra-long distance communication channel by the freezing method according to claim 1, wherein grouting holes (9) are arranged in the communication channel (5) and the pump station.