CN109989391A - A kind of Foundation Pit bottom consolidation by freezing structure and its construction method - Google Patents
A kind of Foundation Pit bottom consolidation by freezing structure and its construction method Download PDFInfo
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- 238000007596 consolidation process Methods 0.000 title claims abstract description 60
- 238000005553 drilling Methods 0.000 claims abstract description 49
- 230000000694 effects Effects 0.000 claims abstract description 15
- 238000002360 preparation method Methods 0.000 claims abstract description 13
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- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 claims description 54
- 239000002689 soil Substances 0.000 claims description 49
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- 150000003839 salts Chemical class 0.000 claims description 27
- 238000009434 installation Methods 0.000 claims description 24
- 239000003507 refrigerant Substances 0.000 claims description 24
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 22
- 238000013461 design Methods 0.000 claims description 22
- 238000005057 refrigeration Methods 0.000 claims description 21
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- 238000001514 detection method Methods 0.000 claims description 9
- 238000011049 filling Methods 0.000 claims description 9
- 239000013505 freshwater Substances 0.000 claims description 9
- 238000007689 inspection Methods 0.000 claims description 9
- 239000010721 machine oil Substances 0.000 claims description 9
- 238000005259 measurement Methods 0.000 claims description 9
- 238000007789 sealing Methods 0.000 claims description 9
- 239000010935 stainless steel Substances 0.000 claims description 9
- 229910001220 stainless steel Inorganic materials 0.000 claims description 9
- 239000013589 supplement Substances 0.000 claims description 9
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 8
- 239000011780 sodium chloride Substances 0.000 claims description 8
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- 230000007246 mechanism Effects 0.000 claims description 4
- 208000012260 Accidental injury Diseases 0.000 claims description 3
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 3
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 3
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- GOLXNESZZPUPJE-UHFFFAOYSA-N spiromesifen Chemical compound CC1=CC(C)=CC(C)=C1C(C(O1)=O)=C(OC(=O)CC(C)(C)C)C11CCCC1 GOLXNESZZPUPJE-UHFFFAOYSA-N 0.000 claims 1
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
- E02D3/11—Improving or preserving soil or rock, e.g. preserving permafrost soil by thermal, electrical or electro-chemical means
- E02D3/115—Improving or preserving soil or rock, e.g. preserving permafrost soil by thermal, electrical or electro-chemical means by freezing
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- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Structural Engineering (AREA)
- Agronomy & Crop Science (AREA)
- Environmental & Geological Engineering (AREA)
- Soil Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
Abstract
The invention discloses a kind of Foundation Pit bottom consolidation by freezing structure and its construction method, Foundation Pit bottom consolidation by freezing structure is that Foundation Pit bottom is provided with consolidation by freezing structure.Consolidation by freezing structure is full hall formula or grating type or skirt edge type or stripping formula, and consolidation by freezing structure is freeze using vertical frozen pipe or horizontal frozen pipe, construction method are as follows: Step 1: preparation of construction；Step 2: foundation pit enclosure structure is constructed；Step 3: drilling construction and freezing system are installed；Step 4: actively freezing to form hole bottom consolidation by freezing structure；Step 5: pulling out freezing pipe；Step 6: excavation of foundation pit is on earth, bottom slab concreting.The utility model has the advantages that having outstanding advantages of construction is practical, quality control on construction is convenient, consolidation effect especially water-stagnating effect is good and safe and reliable, there is biggish application value.
Description
Technical field
The present invention relates to a kind of consolidation by freezing structure and its construction method, in particular to a kind of Foundation Pit bottom consolidation by freezing knot
Structure and its construction method.
Background technique
Currently, foundation pit scale is increasing in China's urban construction, earth excavation is deeper and deeper, and surrounding stable to foundation pit
The influence of Environmental security is also increasing, especially in the base pit engineering of soft clay area, due to the internal friction angle and adhesive aggregation of weak soil
The mechanical index such as power are very low, and weak soil is in that soft modeling or half-flow plastic state if design of foundation pit is improper easily cause the lateral position of building enclosure more
Big, surrounding surface subsidence and bottom heave are moved past, and then influences the stabilization of foundation pit and its safety and normal use of neighbouring facility.
In some more complex underground engineerings in soft clay area, when being often difficult to ensure excavation only with the measure of building enclosure and support
Stabilization and Deformation control, therefore Foundation Pit bottom soil stabilization is also more and more important.Largely engineering practices and theory analysis prove,
The physico-mechanical properties that Foundation Pit subsoil body can be improved well to Foundation Pit bottom soil stabilization play the side for reducing building enclosure
Effect to displacement, surface subsidence and bottom heave improves base pit stability.
Foundation Pit bottom soil stabilization generally uses the methods of cement mixing method, high-pressure rotary jet grouting pile, slip casting, precipitation, generally
It is to mix a certain amount of curing agent in weak soil or make soil solidifying, to improve the mechanical property of hole subsoil body.Wherein mixing pile,
Two kinds of reinforcement means of high-pressure rotary jet grouting pile are using undisturbed soil as reinforcing raw material and curing agent (generally cement or quick lime)
Its mixing is chemically reacted by specific technique, generates hyrate and firm mass of soil particle, using solidifying hard and carbon
Acidification makes the soil body reinforced have the compacted soil pile body of globality, water stability and some strength.No matter rendzinas or water
Soil, their consolidation effect or gain in strength all deposit early stage growth in the short term comparatively fast and the later period continues the spy slowly developed
Point.This aspect is because of feature possessed by curing agent itself, and another aspect is then generally all smaller because of its additive ratio, and
Various reactions are carried out in having certain active medium (soil) encirclement, and reaction is again more complex.They are different from concrete
Condensation hardening mechanism, the latter be mainly cement be hydrolyzed in the small and active weak medium (coarse material) of specific surface area and
Aquation, rate of set are fast.Therefore, reinforced all that there is consolidation effects to Foundation Pit subsoil body using above-mentioned usual manner
With quality it is difficult to ensure that, the disadvantages of soil strength is unevenly distributed after reinforcing.
Summary of the invention
The purpose of the present invention is to solve existing usual manners Foundation Pit subsoil body reinforce it is generally existing
Consolidation effect and quality it is difficult to ensure that, the problem of soil strength is unevenly distributed after reinforcing and a kind of Foundation Pit bottom for providing is freezed
Ruggedized construction and its construction method.
Foundation Pit bottom consolidation by freezing structure provided by the invention is that Foundation Pit bottom is provided with consolidation by freezing structure.
Consolidation by freezing structure is full hall formula or grating type or skirt edge type or stripping formula, and consolidation by freezing structure is frozen using vertical
Knot pipe or horizontal frozen pipe freeze, and when being freezed using horizontal frozen pipe, horizontal frozen pipe is U-shaped, vertically
The diameter of freezing pipe or horizontal frozen pipe is 108-127mm, and the tube spacing of vertical frozen pipe or horizontal frozen pipe is 800mm, row
Spacing is 800mm, the material of vertical frozen pipe or horizontal frozen pipe be seamless low carbon steel pipe or pvc pipe or PPR pipe or ABS pipe or
The section of PE pipe, vertical frozen pipe or horizontal frozen pipe is round or I-shaped or X-shaped or T shape or Y shape.
The construction method of Foundation Pit bottom consolidation by freezing structure provided by the invention, method are as described below:
Step 1: preparation of construction；
Step 2: foundation pit enclosure structure is constructed；
Step 3: drilling construction and freezing system are installed；
Step 4: actively freezing to form hole bottom consolidation by freezing structure；
Step 5: pulling out freezing pipe；
Step 6: excavation of foundation pit is on earth, bottom slab concreting.
Preparation of construction work in step 1 is as described below:
The first situation, preparation of construction work is as follows when using hypothermic saline as coolant media:
One, freeze design:
(1), bottom consolidation by freezing thickness design is cheated:
Incorporation engineering feature, soil layer condition and construction site situation are designed freezing curtain thickness, and foundation is foundation pit
Design theory will mainly meet Resistant heave checking computations；
1), freezing curtain physical parameter:
Frozen soil mean temperature takes -10 DEG C, and frozen soil strength index need to carry out laboratory test measurement；
2), consolidation by freezing structure type:
The consolidation by freezing structure that horizontal layout is full hall formula or grating type or skirt edge type or stripping formula is formed at hole bottom；
(2), the arrangement of freezing hole:
When being freezed using vertical frozen pipe, freezing hole flower arrangement arrangement, pitch of holes 800mm arranges spacing 800mm, close
The vertical frozen hole of foundation pit enclosure structure is apart from building enclosure side 300-400mm；When being freezed using U-shaped freezing pipe, bottom is cheated
The spacing of horizontal segment freezing pipe is 1000mm or 800mm；
(3), thermometer hole is arranged:
The position of thermometer hole is adjusted according to the deflection situation of drilling, to measure freezing curtain range different parts
Temperature development situation, to take corresponding control measure, it is ensured that the safety of construction；
Two, refrigerant system design:
(1) parameter is chosen:
1), vertical frozen pipe or U-shaped freezing pipe select the seamless low carbon steel pipe of 127 × 4.5mm of φ；
2) when, using salt water coolant media, freezing period outlet brine temp be -28 to -30 DEG C, circuit brine temp be -
25 to -28 DEG C；
3), salt water specific gravity 1.26；
4), brine flow 5m in freezing pipe3/h；
5), freezing pipe heat-sinking capability: 260Kcal/m2.h；
6) loss of refrigeration capacity coefficient: 1.2；
(2), chilling requirement calculates:
Freeze chilling requirement calculating: Q=1.2 π dHK
In formula: H-freezes total length；
D-freezes pipe diameter；
K-freezing pipe coefficient of heat transfer；
(3), Freezing Station setting, Unit Selection and quantity:
Freezing Station selects II type screw rod refrigerator two of W-YSLGF600, every unit 28 × 104Kcal/h of refrigerating capacity, electricity
Machine power 220kw；
(4), brine system:
1), salt water conduit tube, collection brine distributing ring type selecting: φ 159 × 5mm welded tube processing and fabricating；
2) three IS150-125-315 type centrifugal water pumps, flow 200m, brine pump type selecting: are selected3/ h, motor 30kw；
(5), clean water system:
1), water pipe type selecting: φ 133 × 4.5mm welded tube processing and fabricating；
2) 8m, is selected3Filtered water tank three；
3), fresh water magnitude of recruitment: 30m3/h；
4) three IS150-125-315 type centrifugal water pumps, flow 200m, are selected3/ h, motor 30kw；
5) KST-80 type cooling tower four, is selected；
(6), consolidation by freezing structure forms prediction:
Take freezing curtain development speed 25mm/ days, freezing pipe maximum pitch of holes takes 800mm, then handing over the circle time is t1=
800/2/25=16 days, the closure of freezing wall time took 20 days, and entire actively freeze-off time takes 30 days or more；
Second situation, preparation of construction work is as follows when using liquid nitrogen as coolant media:
Liquid nitrogen freezing pipe selects 108 × 8mm of Ф low carbon stainless steel pipe, and temperature tube selects 89 × 5mm of Ф stainless-steel pipe, supplies
Liquid pipe and system connecting line select 32 × 3.0mmR304 of Ф stainless steel tube, the material of aforementioned tubing be steel or with PVC,
PPR, ABS and PE plastic material, when selecting plastic material, finally without pulling out freezing pipe；
Select XY-2 type one, drilling machine vertical, power of motor 22KW drills, and selects BW-250/50 type slush pump one
Platform, power of motor 14.5KW；
Different according to the evaporation capacity of liquid nitrogen unit time in freezing pipe, the development speed of frozen soil is 1-5cm/h, takes frozen soil
Development speed be 10cm/ days, liquid nitrogen frozen soil wall thickness will generally reach 1.6m, need the development radius of frozen soil to be about
1100mm, is 10cm/ days by the development speed of frozen soil, calculates freeze-off time away from this are as follows: T=950/10=9.5 days, to ensure to imitate
Fruit need to freeze 11 days, then be judged by the thermometric of thermometer hole, can carry out subsequent construction.
The work that drilling construction and freezing system are installed in step 3 is as described below:
One, the construction to drill:
(1), drilling device type selecting:
XP-30B engineering driller two are selected, matches Te Lasi air compressor machine GR200-20 air compressor machine one, using percussion drilling
Technique is being drilled in hole using setting of casing deviational survey, using Inclination Measurement by Light, use when necessary JDT-5 type gyrolevel deviational survey with
Guarantee drilling vertical precision；
(2), drilling technique requirement:
When drilling, by the needs of depth and strata condition, increase and decrease drill collar in time, accomplish and uniformly, at the uniform velocity creep into, forbids suddenly fast
Suddenly slow, pressure is suddenly big or suddenly small；
Revolving speed, pressure and flushing dose are rationally grasped, when adding ruler or more bit change, is swept under drilling tool at away from bottom hole 0.3-0.5m
Hole, brigadier's drilling tool is not parked in a depth and rinses for a long time, and when power failure, drilling tool is mentioned to safety depth, is had a power failure more than two hours, general
Drilling tool all proposes, to the frequent detailed inspection of all drilling tools, bent drill pipe is forbidden to use with excessive drilling rod is worn, whole hole Shi Fuhe
Drilling tool overall length, and punching empties rock powder, then down tube；
Freezing pipe carries out ground combo, measures overall length, makes a record, and when down tube removes foreign object in pipe, keeps cleaning, pressure testing
After sealing, the gap around freezing pipe is tamped in time with soil, prevents mud string hole；
Deflection: the freezing hole deviation proportion that is averaged is not greater than 5 ‰, and freezing hole end pitch of holes is not more than design value, otherwise gives
Perforations adding, the depth of freezing will meet design requirement, and lower length of tube freezes hole depth not less than design；
Deviational survey: it uses light theodolite to carry out whole hole and pore-forming deviational survey during freezing hole construction and draws freezing hole in time
Deflection plane figure；
Drill site basis: in order to guarantee drilling quality, scene is laid with simple mud groove；
Two, the construction freezed:
(1), the capital equipment of frozen construction:
Screw chiller two, model W-YSLGF600 II, power 220KW；Brine pump 3, model IS150-125-
315, power 30KW；Fresh water pump three, model IS150-125-315, power 30KW；Cooling tower four, model
KST-80, power 4KW；Equipment general power is 666KW；Entire refrigeration station selects the low pressure of YC3 × 120+2 × 25 Plastic-sheathed Cable three
Root freezes unit and corresponding corollary equipment for two respectively；
(2), Freezing Station is installed:
Freezing Station is arranged in side, and two units are installed in parallel, can be mutually spare, and refrigeration station takes up an area 200 square metres；
(4) installation of unit is freezed:
1), in place with fixation:
According to Freezing Station layout drawing, will freeze unit it is in place after, be reliably fixed with bolt and basis, water when fixed
Leveling ruler is levelling to unit progress, is leveled unit by constantly adjusting parallels；
It is arranged according to the pipeline at scene, adjusts two epicranial plate of condenser, optimize the arrangement of pipeline；
Unit starting cabinet is reliably arranged in beside unit, conducive to easy to operate position, while being paid attention between unit
Enough spaces are left, Operation and Maintenance usually are brought convenience；
2), piping connection:
Flanged joint is used between saline line and clear water pipeline and unit, reasonably arrangement installation valve, is conducive to usually
Operation is opened and closed, it is convenient to being provided when safeguarding again；
3), unit sealing detection:
Freezing unit has to guarantee that the sealing performance of unit is reliable, carries out the leak detection of refrigeration system first, is ensuring
After system nothing rushes down leakage, then fill fluorine oiling；
4), unit refuels:
Check that the amount of refrigerator oil in unit will refuel if very few to unit, freezing unit selects 46# refrigerator oil；
(5), clear, brine pump installation:
Check water pump and motor, it is ensured that do not damage in transportation and handling procedure；
Checking tool and hoisting machinery, and the basis of inspection machine；
The basic plane of installation pump carries out level leveling, and the levelness of whole unit is reexamined after placing；
The suction line and discharge pipeline of pump assemble respective bracket, and pipe weight is not allowed directly to be born by pump；
Pump shaft is consistent with motor direction of rotation；
The suction inlet of pump is higher than clear, brine tank bottom 20cm；
One of strainer is installed in the suction inlet of fresh water pump, one of strainer is set among brine tank, to prevent sundries from being inhaled
Enter in pipeline；
It checks that whether there is or not loose phenomenons for pump and pipeline and junction, rotate pump shaft with hand, checks whether pump shaft rotation is flexible；
Bearing lubrication machine oil is added into bearing body, observation oil level should should in time more in the centerline of oil ga(u)ge, lubricating oil
It changes or supplements；
(6), the installation of cooling tower:
Fire Hazard Area in cooling tower installation process is forbidden to generate bright in tower body and its adjacent to using electric welding or gas cutting
Fire；
Cooling tower foundation will keep horizontal, it is desirable that pillar is vertical with basal plane, each basal plane height difference no more than ± 1mm, center away from
Tolerance is ± 2mm；
When tower body assembly, bolt is symmetrically fastened, and does not allow to distort installation by force, must not leak after assembled；
Cooling tower column foot and basic fixation；
Cooling tower components do not allow ballast thereon, must not be exposed to the sun during transport, storage, and pay attention to open fire；
Support of pipelines is separately provided in cooling tower inlet tube and outlet tube and supplement water pipe, avoids pipeline weight transmitting tower body；
Fan blade should be kept properly, and prevent from deforming, and motor and driving member will oil, and be stored indoors；
To avoid sundries from entering nozzle, aperture, carefully to be cleared up before assembling；
Cooling tower after the installation is completed, clears up remains in the dirts such as pipeline, filler surface, water-collecting tray and tower, and carry out in time
System flush；
(7), unit regulation is freezed:
Before refrigeration system debugging, the cleaning and dry work of internal system are first carried out；
1), the filling of refrigerant:
After in-site installation, if visual examination does not find accidental injury, if it find that refrigerant has leaked or insufficient,
Leakage point is found out first and excludes leakage phenomenon, and refrigerant is then added；
It when filling, is directly filled with from dedicated filling liquid valve, refrigerant charge will lead to cooling capacity deficiency, refrigerant less than
Charging amount is excessive, not only will increase expense, and bring adverse effect to operation energy consumption；
2) it, debugs:
Simulated action detection, i.e. unit host no power are done to main electric-control system before formal booting, control system is powered,
Then by unit inner setting, the electric-control system of unit is detected, component whether normal operation, if electric-control system goes out
Existing problem, solves in time, finally leads to upper host power supply again, is debugged；
In debugging process, pay special attention to the following:
Check that whether valve is in normal open state, especially discharge line valve everywhere in refrigeration system, is sure not
It closes；
The flow of the cooling water valve of opening condenser and the Cold water tap of evaporator, cold water and cooling water will meet unit
Technical requirements；
Notice whether the supply voltage of observation unit is normal before starting；
3) it, runs:
According to the requirement of refrigerator operating instruction, start unit；
After unit starting, is required according to unit specification, check whether the parameters of unit are normal；
The all data of unit is recorded, especially some major parameters record clear；
In unit running process, notice whether the increasing of compressor, off-load mechanism work normally；
The safety guard installed in proper use of refrigeration system, if any damage replacement in time；
4), exception monitoring:
Such as there is abnormal conditions, hard stop inspection in screw-type water chiller；
The mark that screw type refrigerating compressor operates normally is as follows:
Compressor Discharge Pressure is 0.8-1.5MPa；
Compressor exhaust temperature is 45-90 DEG C；
The oil temperature of compressor is 40-55 DEG C；
The oil pressure of compressor is 0.2-0.3MPa；
Sound in compressor operational process will uniformly, steadily, sound without exception；
The condensation temperature of unit is 3-5 DEG C higher than cooling water temperature；Condensation temperature is controlled at 40 DEG C, and condenser inflow temperature exists
32 DEG C or less；
The evaporating temperature of unit is 3-4 DEG C lower than the leaving water temperature of chilled water, and chilled water leaving water temperature is 5-7 DEG C；
(8), clear, brine pump debugging:
It checks that whether there is or not loose phenomenons for pump and pipeline and junction, are rotated with hand and are pumped, tries whether pump shaft rotation is flexible；
Bearing lubrication machine oil is added into bearing body, observation oil level should should in time more in the centerline of oil ga(u)ge, lubricating oil
It changes or supplements；
Crawl motor tries whether motor steering is correct；
Motor is started, after pumping normal operation, delivery gauge is opened and after showing appropriate pressure depending on it, gradually beats
Valve is opened a sluice gate, while checking motor load situation；
It is excessive whether the observation pump housing and pipeline vibrate, and parking checking reason is wanted when excessive and is handled；
In the range that the flow and lift for controlling pump as far as possible indicate on label, to guarantee that pump is operated in best efficiency point,
Maximum energy-saving effect could be obtained；
In the process of running, for bearing temperature no more than 35 DEG C of environment temperature, maximum temperature must not exceed 80 DEG C to pump；
Such as find that pump has abnormal sound will parking checking reason immediately；
(9), other:
Freeze machine oil and selects N46 refrigerator oil；
Refrigerant selects freon R-22；
Refrigerant agent selects calcium chloride solution.
The work that freezing pipe is pulled out in step 5 is as described below:
(1), forced thaw:
Using the artificial scheme locally thawed, is recycled in frigo using hot salt brine, melt the frozen soil around freezing pipe
Change；
(2), salt water heats:
With a 3m3The brine tank of left and right stores salt water, carries out heating salt water, temperature control with the heating wire of six groups of 20kw
At 75 ± 10 DEG C；
(3), brine recycling:
Utilize brine pump circulating brine, Model of pump IS150-125-315, the brine recycling flow control of each freezing hole
System is in 5-7m3/h；
(4), it thaws and measures:
Using the thermometer hole in freezing curtain, the variation of daily Timing measurement curtain temperature, until freezing curtain rises to
Until positive temperature, then stop defrosting operation；
(5), freezing pipe rises and pulls out:
After freezing pipe thaws, interior salt water discharge will be managed with compressed air, examination is carried out using crane and is pulled out, 0.5m or so is pulled up
When, it is ensured that after without exception, quickly extract freezing pipe, tube drawing pays attention to freezing pipe and hook wants being aligned, and freezing pipe cannot sprain strength, pulls out
Often micro- rotation freezing pipe is wanted when pipe, freezing pipe cannot pull out firmly, when such as pulling out motionless, hot salt brine defrosting be continued cycling through, until can pull out
Until playing freezing pipe.
Beneficial effects of the present invention:
It the present invention provides a kind of Foundation Pit bottom consolidation by freezing structure and its construction method, the present invention is added using freezing process
Gu the mode of the soil body reinforces Foundation Pit subsoil body, freezed by hypothermic saline or liquid nitrogen freezing, forms full hall at hole bottom
The consolidation by freezing structure of formula or grating type or skirt edge type or stripping formula carries out foundation pit after consolidation by freezing structure formation and opens
It digs, to guarantee the stability of excavation of foundation pit.By being put into vertical or U-shaped freezing pipe in earth drilling, recycled in freezing pipe
Hypothermic saline or liquid nitrogen make weak soil form frozen soil.Freezing pipe is carried out directed local and is freezed, i.e., only in the bottom soil stabilization thickness of hole
Implementation is freezed, and cheats bottom or more and does not freeze.Practical, quality control on construction is convenient, consolidation effect is special with constructing by the present invention
It is outstanding advantages of water-stagnating effect is good and safe and reliable, there is biggish application value.
Detailed description of the invention
Fig. 1 is the consolidation by freezing structural schematic diagram of the present invention when being freezed using vertical frozen pipe.
Fig. 2 is the consolidation by freezing structural schematic diagram of the present invention when being freezed using U-shaped freezing pipe.
Fig. 3 is full hall formula consolidation by freezing structure overlooking structure diagram of the present invention.
Fig. 4 is grating type consolidation by freezing structure overlooking structure diagram of the present invention.
Fig. 5 is skirt edge type consolidation by freezing structure overlooking structure diagram of the present invention.
Fig. 6 is stripping formula consolidation by freezing structure overlooking structure diagram of the present invention.
Fig. 7 is the construction process schematic diagram of Foundation Pit bottom consolidation by freezing structure of the present invention.
Mark in above-mentioned figure is as follows:
1, consolidation by freezing structure 2, vertical frozen pipe 3, horizontal frozen pipe.
Specific embodiment
It please refers to shown in Fig. 1 to Fig. 7:
Foundation Pit bottom consolidation by freezing structure provided by the invention is that Foundation Pit bottom is provided with consolidation by freezing structure 1.
Consolidation by freezing structure 1 is full hall formula or grating type or skirt edge type or stripping formula, and consolidation by freezing structure 1 is using vertical
Freezing pipe 2 or horizontal frozen pipe 3 freeze, and when being freezed using horizontal frozen pipe 3, horizontal frozen pipe 3 is U-shaped
The diameter of type, vertical frozen pipe 2 or horizontal frozen pipe 3 is 108-127mm, the tube spacing of vertical frozen pipe 2 or horizontal frozen pipe 3
Be 800mm for 800mm, row's spacing, the material of vertical frozen pipe 2 or horizontal frozen pipe 3 be seamless low carbon steel pipe or pvc pipe or
The section of PPR pipe or ABS pipe or PE pipe, vertical frozen pipe 2 or horizontal frozen pipe 3 is round or I-shaped or X-shaped or T shape or Y
Shape.
The construction method of Foundation Pit bottom consolidation by freezing structure provided by the invention, method are as described below:
Step 1: preparation of construction；
Step 2: foundation pit enclosure structure is constructed；
Step 3: drilling construction and freezing system are installed；
Step 4: actively freezing to form hole bottom consolidation by freezing structure 1；
Step 5: pulling out freezing pipe；
Step 6: excavation of foundation pit is on earth, bottom slab concreting.
Preparation of construction work in step 1 is as described below:
The first situation, preparation of construction work is as follows when using hypothermic saline as coolant media:
One, freeze design:
(1), bottom consolidation by freezing thickness design is cheated:
Incorporation engineering feature, soil layer condition and construction site situation are designed freezing curtain thickness, and foundation is foundation pit
Design theory will mainly meet Resistant heave checking computations；
1), freezing curtain physical parameter:
Frozen soil mean temperature takes -10 DEG C, and frozen soil strength index need to carry out laboratory test measurement；
2), 1 form of consolidation by freezing structure:
The consolidation by freezing structure 1 that horizontal layout is full hall formula or grating type or skirt edge type or stripping formula is formed at hole bottom；
(2), the arrangement of freezing hole:
When being freezed using vertical frozen pipe 2, freezing hole flower arrangement arrangement, pitch of holes 800mm arranges spacing 800mm, close
The vertical frozen hole of foundation pit enclosure structure is apart from building enclosure side 300-400mm；When being freezed using U-shaped freezing pipe, bottom is cheated
The spacing of horizontal segment freezing pipe is 1000mm or 800mm；
(3), thermometer hole is arranged:
The position of thermometer hole is adjusted according to the deflection situation of drilling, to measure freezing curtain range different parts
Temperature development situation, to take corresponding control measure, it is ensured that the safety of construction；
Two, refrigerant system design:
(1) parameter is chosen:
1), vertical frozen pipe 1 or U-shaped freezing pipe select the seamless low carbon steel pipe of 127 × 4.5mm of φ；
2) when, using salt water coolant media, freezing period outlet brine temp be -28 to -30 DEG C, circuit brine temp be -
25 to -28 DEG C；
3), salt water specific gravity 1.26；
4), brine flow 5m in freezing pipe3/h；
5), freezing pipe heat-sinking capability: 260Kcal/m2.h；
6) loss of refrigeration capacity coefficient: 1.2；
(2), chilling requirement calculates:
Freeze chilling requirement calculating: Q=1.2 π dHK
In formula: H-freezes total length；
D-freezes pipe diameter；
K-freezing pipe coefficient of heat transfer；
(3), Freezing Station setting, Unit Selection and quantity:
Freezing Station selects II type screw rod refrigerator two of W-YSLGF600, every unit 28 × 104Kcal/h of refrigerating capacity, electricity
Machine power 220kw；
(4), brine system:
1), salt water conduit tube, collection brine distributing ring type selecting: φ 159 × 5mm welded tube processing and fabricating；
2) three IS150-125-315 type centrifugal water pumps, flow 200m, brine pump type selecting: are selected3/ h, motor 30kw；
(5), clean water system:
1), water pipe type selecting: φ 133 × 4.5mm welded tube processing and fabricating；
2) 8m, is selected3Filtered water tank three；
3), fresh water magnitude of recruitment: 30m3/h；
4) three IS150-125-315 type centrifugal water pumps, flow 200m, are selected3/ h, motor 30kw；
5) KST-80 type cooling tower four, is selected；
(6), consolidation by freezing structure 1 forms prediction:
Take freezing curtain development speed 25mm/ days, freezing pipe maximum pitch of holes takes 800mm, then handing over the circle time is t1=
800/2/25=16 days, the closure of freezing wall time took 20 days, and entire actively freeze-off time takes 30 days or more；
Second situation, preparation of construction work is as follows when using liquid nitrogen as coolant media:
Liquid nitrogen freezing pipe selects 108 × 8mm of Ф low carbon stainless steel pipe, and temperature tube selects 89 × 5mm of Ф stainless-steel pipe, supplies
Liquid pipe and system connecting line select 32 × 3.0mmR304 of Ф stainless steel tube, the material of aforementioned tubing be steel or with PVC,
PPR, ABS and PE plastic material, when selecting plastic material, finally without pulling out freezing pipe；
Select XY-2 type one, drilling machine vertical, power of motor 22KW drills, and selects BW-250/50 type slush pump one
Platform, power of motor 14.5KW；
Different according to the evaporation capacity of liquid nitrogen unit time in freezing pipe, the development speed of frozen soil is 1-5cm/h, takes frozen soil
Development speed be 10cm/ days, liquid nitrogen frozen soil wall thickness will generally reach 1.6m, need the development radius of frozen soil to be about
1100mm, is 10cm/ days by the development speed of frozen soil, calculates freeze-off time away from this are as follows: T=950/10=9.5 days, to ensure to imitate
Fruit need to freeze 11 days, then be judged by the thermometric of thermometer hole, can carry out subsequent construction.
The work that drilling construction and freezing system are installed in step 3 is as described below:
One, the construction to drill:
(1), drilling device type selecting:
XP-30B engineering driller two are selected, matches Te Lasi air compressor machine GR200-20 air compressor machine one, using percussion drilling
Technique is being drilled in hole using setting of casing deviational survey, using Inclination Measurement by Light, use when necessary JDT-5 type gyrolevel deviational survey with
Guarantee drilling vertical precision；
(2), drilling technique requirement:
When drilling, by the needs of depth and strata condition, increase and decrease drill collar in time, accomplish and uniformly, at the uniform velocity creep into, forbids suddenly fast
Suddenly slow, pressure is suddenly big or suddenly small；
Revolving speed, pressure and flushing dose are rationally grasped, when adding ruler or more bit change, is swept under drilling tool at away from bottom hole 0.3-0.5m
Hole, brigadier's drilling tool is not parked in a depth and rinses for a long time, and when power failure, drilling tool is mentioned to safety depth, is had a power failure more than two hours, general
Drilling tool all proposes, to the frequent detailed inspection of all drilling tools, bent drill pipe is forbidden to use with excessive drilling rod is worn, whole hole Shi Fuhe
Drilling tool overall length, and punching empties rock powder, then down tube；
Freezing pipe carries out ground combo, measures overall length, makes a record, and when down tube removes foreign object in pipe, keeps cleaning, pressure testing
After sealing, the gap around freezing pipe is tamped in time with soil, prevents mud string hole；
Deflection: the freezing hole deviation proportion that is averaged is not greater than 5 ‰, and freezing hole end pitch of holes is not more than design value, otherwise gives
Perforations adding, the depth of freezing will meet design requirement, and lower length of tube freezes hole depth not less than design；
Deviational survey: it uses light theodolite to carry out whole hole and pore-forming deviational survey during freezing hole construction and draws freezing hole in time
Deflection plane figure；
Drill site basis: in order to guarantee drilling quality, scene is laid with simple mud groove；
Two, the construction freezed:
(1), the capital equipment of frozen construction:
Screw chiller two, model W-YSLGF600 II, power 220KW；Brine pump 3, model IS150-125-
315, power 30KW；Fresh water pump three, model IS150-125-315, power 30KW；Cooling tower four, model
KST-80, power 4KW；Equipment general power is 666KW；Entire refrigeration station selects the low pressure of YC3 × 120+2 × 25 Plastic-sheathed Cable three
Root freezes unit and corresponding corollary equipment for two respectively；
(2), Freezing Station is installed:
Freezing Station is arranged in side, and two units are installed in parallel, can be mutually spare, and refrigeration station takes up an area 200 square metres；
(4) installation of unit is freezed:
1), in place with fixation:
According to Freezing Station layout drawing, will freeze unit it is in place after, be reliably fixed with bolt and basis, water when fixed
Leveling ruler is levelling to unit progress, is leveled unit by constantly adjusting parallels；
It is arranged according to the pipeline at scene, adjusts two epicranial plate of condenser, optimize the arrangement of pipeline；
Unit starting cabinet is reliably arranged in beside unit, conducive to easy to operate position, while being paid attention between unit
Enough spaces are left, Operation and Maintenance usually are brought convenience；
2), piping connection:
Flanged joint is used between saline line and clear water pipeline and unit, reasonably arrangement installation valve, is conducive to usually
Operation is opened and closed, it is convenient to being provided when safeguarding again；
3), unit sealing detection:
Freezing unit has to guarantee that the sealing performance of unit is reliable, carries out the leak detection of refrigeration system first, is ensuring
After system nothing rushes down leakage, then fill fluorine oiling；
4), unit refuels:
Check that the amount of refrigerator oil in unit will refuel if very few to unit, freezing unit selects 46# refrigerator oil；
(5), clear, brine pump installation:
Check water pump and motor, it is ensured that do not damage in transportation and handling procedure；
Checking tool and hoisting machinery, and the basis of inspection machine；
The basic plane of installation pump carries out level leveling, and the levelness of whole unit is reexamined after placing；
The suction line and discharge pipeline of pump assemble respective bracket, and pipe weight is not allowed directly to be born by pump；
Pump shaft is consistent with motor direction of rotation；
The suction inlet of pump is higher than clear, brine tank bottom 20cm；
One of strainer is installed in the suction inlet of fresh water pump, one of strainer is set among brine tank, to prevent sundries from being inhaled
Enter in pipeline；
It checks that whether there is or not loose phenomenons for pump and pipeline and junction, rotate pump shaft with hand, checks whether pump shaft rotation is flexible；
Bearing lubrication machine oil is added into bearing body, observation oil level should should in time more in the centerline of oil ga(u)ge, lubricating oil
It changes or supplements；
(6), the installation of cooling tower:
Fire Hazard Area in cooling tower installation process is forbidden to generate bright in tower body and its adjacent to using electric welding or gas cutting
Fire；
Cooling tower foundation will keep horizontal, it is desirable that pillar is vertical with basal plane, each basal plane height difference no more than ± 1mm, center away from
Tolerance is ± 2mm；
When tower body assembly, bolt is symmetrically fastened, and does not allow to distort installation by force, must not leak after assembled；
Cooling tower column foot and basic fixation；
Cooling tower components do not allow ballast thereon, must not be exposed to the sun during transport, storage, and pay attention to open fire；
Support of pipelines is separately provided in cooling tower inlet tube and outlet tube and supplement water pipe, avoids pipeline weight transmitting tower body；
Fan blade should be kept properly, and prevent from deforming, and motor and driving member will oil, and be stored indoors；
To avoid sundries from entering nozzle, aperture, carefully to be cleared up before assembling；
Cooling tower after the installation is completed, clears up remains in the dirts such as pipeline, filler surface, water-collecting tray and tower, and carry out in time
System flush；
(7), unit regulation is freezed:
Before refrigeration system debugging, the cleaning and dry work of internal system are first carried out；
1), the filling of refrigerant:
After in-site installation, if visual examination does not find accidental injury, if it find that refrigerant has leaked or insufficient,
Leakage point is found out first and excludes leakage phenomenon, and refrigerant is then added；
It when filling, is directly filled with from dedicated filling liquid valve, refrigerant charge will lead to cooling capacity deficiency, refrigerant less than
Charging amount is excessive, not only will increase expense, and bring adverse effect to operation energy consumption；
2) it, debugs:
Simulated action detection, i.e. unit host no power are done to main electric-control system before formal booting, control system is powered,
Then by unit inner setting, the electric-control system of unit is detected, component whether normal operation, if electric-control system goes out
Existing problem, solves in time, finally leads to upper host power supply again, is debugged；
In debugging process, pay special attention to the following:
Check that whether valve is in normal open state, especially discharge line valve everywhere in refrigeration system, is sure not
It closes；
The flow of the cooling water valve of opening condenser and the Cold water tap of evaporator, cold water and cooling water will meet unit
Technical requirements；
Notice whether the supply voltage of observation unit is normal before starting；
3) it, runs:
According to the requirement of refrigerator operating instruction, start unit；
After unit starting, is required according to unit specification, check whether the parameters of unit are normal；
The all data of unit is recorded, especially some major parameters record clear；
In unit running process, notice whether the increasing of compressor, off-load mechanism work normally；
The safety guard installed in proper use of refrigeration system, if any damage replacement in time；
4), exception monitoring:
Such as there is abnormal conditions, hard stop inspection in screw-type water chiller；
The mark that screw type refrigerating compressor operates normally is as follows:
Compressor Discharge Pressure is 0.8-1.5MPa；
Compressor exhaust temperature is 45-90 DEG C；
The oil temperature of compressor is 40-55 DEG C；
The oil pressure of compressor is 0.2-0.3MPa；
Sound in compressor operational process will uniformly, steadily, sound without exception；
The condensation temperature of unit is 3-5 DEG C higher than cooling water temperature；Condensation temperature is controlled at 40 DEG C, and condenser inflow temperature exists
32 DEG C or less；
The evaporating temperature of unit is 3-4 DEG C lower than the leaving water temperature of chilled water, and chilled water leaving water temperature is 5-7 DEG C；
(8), clear, brine pump debugging:
It checks that whether there is or not loose phenomenons for pump and pipeline and junction, are rotated with hand and are pumped, tries whether pump shaft rotation is flexible；
Bearing lubrication machine oil is added into bearing body, observation oil level should should in time more in the centerline of oil ga(u)ge, lubricating oil
It changes or supplements；
Crawl motor tries whether motor steering is correct；
Motor is started, after pumping normal operation, delivery gauge is opened and after showing appropriate pressure depending on it, gradually beats
Valve is opened a sluice gate, while checking motor load situation；
It is excessive whether the observation pump housing and pipeline vibrate, and parking checking reason is wanted when excessive and is handled；
In the range that the flow and lift for controlling pump as far as possible indicate on label, to guarantee that pump is operated in best efficiency point,
Maximum energy-saving effect could be obtained；
In the process of running, for bearing temperature no more than 35 DEG C of environment temperature, maximum temperature must not exceed 80 DEG C to pump；
Such as find that pump has abnormal sound will parking checking reason immediately；
(9), other:
Freeze machine oil and selects N46 refrigerator oil；
Refrigerant selects freon R-22；
Refrigerant agent selects calcium chloride solution.
The work that freezing pipe is pulled out in step 5 is as described below:
(1), forced thaw:
Using the artificial scheme locally thawed, is recycled in frigo using hot salt brine, melt the frozen soil around freezing pipe
Change；
(2), salt water heats:
With a 3m3The brine tank of left and right stores salt water, carries out heating salt water, temperature control with the heating wire of six groups of 20kw
At 75 ± 10 DEG C；
(3), brine recycling:
Utilize brine pump circulating brine, Model of pump IS150-125-315, the brine recycling flow control of each freezing hole
System is in 5-7m3/h；
(4), it thaws and measures:
Using the thermometer hole in freezing curtain, the variation of daily Timing measurement curtain temperature, until freezing curtain rises to
Until positive temperature, then stop defrosting operation；
(5), freezing pipe rises and pulls out:
After freezing pipe thaws, interior salt water discharge will be managed with compressed air, examination is carried out using crane and is pulled out, 0.5m or so is pulled up
When, it is ensured that after without exception, quickly extract freezing pipe, tube drawing pays attention to freezing pipe and hook wants being aligned, and freezing pipe cannot sprain strength, pulls out
Often micro- rotation freezing pipe is wanted when pipe, freezing pipe cannot pull out firmly, when such as pulling out motionless, hot salt brine defrosting be continued cycling through, until can pull out
Until playing freezing pipe.
Claims (6)
1. a kind of Foundation Pit bottom consolidation by freezing structure, it is characterised in that: be that Foundation Pit bottom is provided with consolidation by freezing structure.
2. a kind of Foundation Pit bottom consolidation by freezing structure according to claim 1, it is characterised in that: the consolidation by freezing knot
Structure is full hall formula or grating type or skirt edge type or stripping formula, consolidation by freezing structure be using vertical frozen pipe or horizontal frozen pipe into
Row freezes, and when being freezed using horizontal frozen pipe, horizontal frozen pipe is U-shaped, vertical frozen pipe or horizontal frozen pipe
Diameter be 108-127mm, the tube spacing of vertical frozen pipe or horizontal frozen pipe is 800mm, row's spacing is 800mm, vertical to freeze
The material of knot pipe or horizontal frozen pipe is seamless low carbon steel pipe or pvc pipe or PPR pipe or ABS pipe or PE pipe, vertical frozen pipe or
The section of horizontal frozen pipe is round or I-shaped or X-shaped or T shape or Y shape.
3. a kind of construction method of Foundation Pit bottom consolidation by freezing structure, it is characterised in that: its method is as described below:
Step 1: preparation of construction；
Step 2: foundation pit enclosure structure is constructed；
Step 3: drilling construction and freezing system are installed；
Step 4: actively freezing to form hole bottom consolidation by freezing structure；
Step 5: pulling out freezing pipe；
Step 6: excavation of foundation pit is on earth, bottom slab concreting.
4. a kind of construction method of Foundation Pit bottom consolidation by freezing structure according to claim 3, it is characterised in that: described
Preparation of construction work in step 1 is as described below:
The first situation, preparation of construction work is as follows when using hypothermic saline as coolant media:
One, freeze design:
(1), bottom consolidation by freezing thickness design is cheated:
Incorporation engineering feature, soil layer condition and construction site situation are designed freezing curtain thickness, and foundation is design of foundation pit
Theory will mainly meet Resistant heave checking computations；
1), freezing curtain physical parameter:
Frozen soil mean temperature takes -10 DEG C, and frozen soil strength index need to carry out laboratory test measurement；
2), consolidation by freezing structure type:
The consolidation by freezing structure that horizontal layout is full hall formula or grating type or skirt edge type or stripping formula is formed at hole bottom；
(2), the arrangement of freezing hole:
When being freezed using vertical frozen pipe, freezing hole flower arrangement arrangement, pitch of holes 800mm arranges spacing 800mm, close to foundation pit
The vertical frozen hole of building enclosure is apart from building enclosure side 300-400mm；When being freezed using U-shaped freezing pipe, hole bottom water is flat
The spacing of section freezing pipe is 1000mm or 800mm；
(3), thermometer hole is arranged:
The position of thermometer hole is adjusted according to the deflection situation of drilling, to measure the temperature of freezing curtain range different parts
State of development is spent, to take corresponding control measure, it is ensured that the safety of construction；
Two, refrigerant system design:
(1) parameter is chosen:
1), vertical frozen pipe or U-shaped freezing pipe select the seamless low carbon steel pipe of 127 × 4.5mm of φ；
2) when, using salt water coolant media, freezing period outlet brine temp be -28 to -30 DEG C, circuit brine temp be -25 to -
28℃；
3), salt water specific gravity 1.26；
4), brine flow 5m in freezing pipe3/h；
5), freezing pipe heat-sinking capability: 260Kcal/m2.h；
6) loss of refrigeration capacity coefficient: 1.2；
(2), chilling requirement calculates:
Freeze chilling requirement calculating: Q=1.2 π dHK
In formula: H-freezes total length；
D-freezes pipe diameter；
K-freezing pipe coefficient of heat transfer；
(3), Freezing Station setting, Unit Selection and quantity:
Freezing Station selects II type screw rod refrigerator two of W-YSLGF600, every unit 28 × 104Kcal/h of refrigerating capacity, motor function
Rate 220kw；
(4), brine system:
1), salt water conduit tube, collection brine distributing ring type selecting: φ 159 × 5mm welded tube processing and fabricating；
2) three IS150-125-315 type centrifugal water pumps, flow 200m, brine pump type selecting: are selected3/ h, motor 30kw；
(5), clean water system:
1), water pipe type selecting: φ 133 × 4.5mm welded tube processing and fabricating；
2) 8m, is selected3Filtered water tank three；
3), fresh water magnitude of recruitment: 30m3/h；
4) three IS150-125-315 type centrifugal water pumps, flow 200m, are selected3/ h, motor 30kw；
5) KST-80 type cooling tower four, is selected；
(6), consolidation by freezing structure forms prediction:
Take freezing curtain development speed 25mm/ days, freezing pipe maximum pitch of holes takes 800mm, then handing over the circle time is t1=800/2/
25=16 days, the closure of freezing wall time took 20 days, and entire actively freeze-off time takes 30 days or more；
Second situation, preparation of construction work is as follows when using liquid nitrogen as coolant media:
Liquid nitrogen freezing pipe selects 108 × 8mm of Ф low carbon stainless steel pipe, and temperature tube selects 89 × 5mm of Ф stainless-steel pipe, liquid supply pipe
And system connecting line select 32 × 3.0mmR304 of Ф stainless steel tube, the material of aforementioned tubing be steel or with PVC, PPR,
ABS and PE plastic material, when selecting plastic material, finally without pulling out freezing pipe；
Select XY-2 type one, drilling machine vertical, power of motor 22KW drills, one, BW-250/50 type slush pump is selected,
Power of motor 14.5KW；
Different according to the evaporation capacity of liquid nitrogen unit time in freezing pipe, the development speed of frozen soil is 1-5cm/h, takes the hair of frozen soil
Opening up speed is 10cm/ days, and liquid nitrogen frozen soil wall thickness will generally reach 1.6m, and needing the development radius of frozen soil is about 1100mm, press
The development speed of frozen soil is 10cm/ days, calculates freeze-off time away from this are as follows: T=950/10=9.5 days, to ensure effect, need to freeze
11 days, then judged by the thermometric of thermometer hole, subsequent construction can be carried out.
5. a kind of construction method of Foundation Pit bottom consolidation by freezing structure according to claim 3, it is characterised in that: described
The work that drilling construction and freezing system are installed in step 3 is as described below:
One, the construction to drill:
(1), drilling device type selecting:
XP-30B engineering driller two are selected, matches Te Lasi air compressor machine GR200-20 air compressor machine one, using percussion drilling work
Skill uses JDT-5 type gyrolevel deviational survey to protect when necessary using setting of casing deviational survey being drilled in hole using Inclination Measurement by Light
Card drilling vertical precision；
(2), drilling technique requirement:
When drilling, by the needs of depth and strata condition, increase and decrease drill collar in time, accomplishes and uniformly, at the uniform velocity creep into, forbid to neglect fastly suddenly
Slowly, pressure is suddenly big or suddenly small；
Revolving speed, pressure and flushing dose are rationally grasped, is arrived when adding ruler or more bit change, under drilling tool away from cleaning bottom of hole at bottom hole 0.3-0.5m,
Brigadier's drilling tool is not parked in a depth and rinses for a long time, when power failure, drilling tool is mentioned to safety depth, has a power failure more than two hours, will bore
Tool all proposes, to the frequent detailed inspection of all drilling tools, bent drill pipe and wears excessive drilling rod and is forbidden to use, and review is bored when whole hole
Has overall length, and punching empties rock powder, then down tube；
Freezing pipe carries out ground combo, measures overall length, makes a record, and when down tube removes foreign object in pipe, keeps cleaning, pressure testing sealing
Afterwards, the gap around freezing pipe is tamped in time with soil, prevents mud string hole；
Deflection: the freezing hole deviation proportion that is averaged is not greater than 5 ‰, and freezing hole end pitch of holes is not more than design value, otherwise gives perforations adding,
The depth of freezing will meet design requirement, and lower length of tube freezes hole depth not less than design；
Deviational survey: it uses light theodolite to carry out whole hole and pore-forming deviational survey during freezing hole construction and draws slanting of freezing hole in time
Plan view；
Drill site basis: in order to guarantee drilling quality, scene is laid with simple mud groove；
Two, the construction freezed:
(1), the capital equipment of frozen construction:
Screw chiller two, model W-YSLGF600 II, power 220KW；Brine pump 3, model IS150-125-315,
Power is 30KW；Fresh water pump three, model IS150-125-315, power 30KW；Cooling tower four, model KST-80,
Power is 4KW；Equipment general power is 666KW；Entire refrigeration station selects the low pressure of YC3 × 120+2 × 25 Plastic-sheathed Cable three, respectively
Freeze unit and corresponding corollary equipment for two；
(2), Freezing Station is installed:
Freezing Station is arranged in side, and two units are installed in parallel, can be mutually spare, and refrigeration station takes up an area 200 square metres；
(4) installation of unit is freezed:
1), in place with fixation:
According to Freezing Station layout drawing, will freeze unit it is in place after, be reliably fixed with bolt and basis, horizontal ruler when fixed
It is levelling to unit progress, unit is leveled by constantly adjusting parallels；
It is arranged according to the pipeline at scene, adjusts two epicranial plate of condenser, optimize the arrangement of pipeline；
Unit starting cabinet is reliably arranged in beside unit, conducive to easy to operate position, while paying attention to leaving between unit
Enough spaces will bring convenience Operation and Maintenance usually；
2), piping connection:
Flanged joint is used between saline line and clear water pipeline and unit, reasonably arrangement installation valve, conducive to usually opening
It is convenient to being provided when safeguarding again with shutoff operation；
3), unit sealing detection:
Freezing unit have to guarantee unit sealing performance it is reliable, first carry out refrigeration system leak detection, ensure system without
After rushing down leakage, then fill fluorine oiling；
4), unit refuels:
Check that the amount of refrigerator oil in unit will refuel if very few to unit, freezing unit selects 46# refrigerator oil；
(5), clear, brine pump installation:
Check water pump and motor, it is ensured that do not damage in transportation and handling procedure；
Checking tool and hoisting machinery, and the basis of inspection machine；
The basic plane of installation pump carries out level leveling, and the levelness of whole unit is reexamined after placing；
The suction line and discharge pipeline of pump assemble respective bracket, and pipe weight is not allowed directly to be born by pump；
Pump shaft is consistent with motor direction of rotation；
The suction inlet of pump is higher than clear, brine tank bottom 20cm；
One of strainer is installed in the suction inlet of fresh water pump, one of strainer is set among brine tank, to prevent sundries to be inhaled into pipe
In road；
It checks that whether there is or not loose phenomenons for pump and pipeline and junction, rotate pump shaft with hand, checks whether pump shaft rotation is flexible；
Into bearing body be added bearing lubrication machine oil, observation oil level should should be replaced in time in the centerline of oil ga(u)ge, lubricating oil or
Supplement；
(6), the installation of cooling tower:
Fire Hazard Area in cooling tower installation process forbids that open fire cannot be generated in tower body and its adjacent to using electric welding or gas cutting；
Cooling tower foundation will keep horizontal, it is desirable that pillar is vertical with basal plane, and each basal plane height difference is no more than ± 1mm, and center is away from permission
Difference is ± 2mm；
When tower body assembly, bolt is symmetrically fastened, and does not allow to distort installation by force, must not leak after assembled；
Cooling tower column foot and basic fixation；
Cooling tower components do not allow ballast thereon, must not be exposed to the sun during transport, storage, and pay attention to open fire；
Support of pipelines is separately provided in cooling tower inlet tube and outlet tube and supplement water pipe, avoids pipeline weight transmitting tower body；
Fan blade should be kept properly, and prevent from deforming, and motor and driving member will oil, and be stored indoors；
To avoid sundries from entering nozzle, aperture, carefully to be cleared up before assembling；
Cooling tower after the installation is completed, clears up remains in the dirts such as pipeline, filler surface, water-collecting tray and tower, and carry out system in time
It rinses；
(7), unit regulation is freezed:
Before refrigeration system debugging, the cleaning and dry work of internal system are first carried out；
1), the filling of refrigerant:
After in-site installation, if visual examination does not find accidental injury, if it find that refrigerant has leaked or insufficient, first
It finds out leakage point and excludes leakage phenomenon, refrigerant is then added；
It when filling, is directly filled with from dedicated filling liquid valve, refrigerant charge will lead to cooling capacity deficiency, refrigerant charging less than
Amount is excessive, not only will increase expense, and bring adverse effect to operation energy consumption；
2) it, debugs:
Simulated action detection, i.e. unit host no power are done to main electric-control system before formal booting, control system is powered, then
By unit inner setting, the electric-control system of unit is detected, component whether normal operation, if electric-control system is asked
Topic solves in time, finally leads to upper host power supply again, is debugged；
In debugging process, pay special attention to the following:
Check that whether valve is in normal open state, especially discharge line valve everywhere in refrigeration system, is sure not to close；
The flow of the cooling water valve of opening condenser and the Cold water tap of evaporator, cold water and cooling water will meet machine set technology
It is required that；
Notice whether the supply voltage of observation unit is normal before starting；
3) it, runs:
According to the requirement of refrigerator operating instruction, start unit；
After unit starting, is required according to unit specification, check whether the parameters of unit are normal；
The all data of unit is recorded, especially some major parameters record clear；
In unit running process, notice whether the increasing of compressor, off-load mechanism work normally；
The safety guard installed in proper use of refrigeration system, if any damage replacement in time；
4), exception monitoring:
Such as there is abnormal conditions, hard stop inspection in screw-type water chiller；
The mark that screw type refrigerating compressor operates normally is as follows:
Compressor Discharge Pressure is 0.8-1.5MPa；
Compressor exhaust temperature is 45-90 DEG C；
The oil temperature of compressor is 40-55 DEG C；
The oil pressure of compressor is 0.2-0.3MPa；
Sound in compressor operational process will uniformly, steadily, sound without exception；
The condensation temperature of unit is 3-5 DEG C higher than cooling water temperature；Condensation temperature is controlled at 40 DEG C, and condenser inflow temperature is at 32 DEG C
Below；
The evaporating temperature of unit is 3-4 DEG C lower than the leaving water temperature of chilled water, and chilled water leaving water temperature is 5-7 DEG C；
(8), clear, brine pump debugging:
It checks that whether there is or not loose phenomenons for pump and pipeline and junction, are rotated with hand and are pumped, tries whether pump shaft rotation is flexible；
Into bearing body be added bearing lubrication machine oil, observation oil level should should be replaced in time in the centerline of oil ga(u)ge, lubricating oil or
Supplement；
Crawl motor tries whether motor steering is correct；
Motor is started, after pumping normal operation, delivery gauge is opened and after showing appropriate pressure depending on it, is gradually opened lock
Valve, while checking motor load situation；
It is excessive whether the observation pump housing and pipeline vibrate, and parking checking reason is wanted when excessive and is handled；
In the range that the flow and lift for controlling pump as far as possible indicate on label, to guarantee that pump is operated in best efficiency point, ability
Obtain maximum energy-saving effect；
In the process of running, for bearing temperature no more than 35 DEG C of environment temperature, maximum temperature must not exceed 80 DEG C to pump；
Such as find that pump has abnormal sound will parking checking reason immediately；
(9), other:
Freeze machine oil and selects N46 refrigerator oil；
Refrigerant selects freon R-22；
Refrigerant agent selects calcium chloride solution.
6. a kind of construction method of Foundation Pit bottom consolidation by freezing structure according to claim 3, it is characterised in that: described
The work that freezing pipe is pulled out in step 5 is as described below:
(1), forced thaw:
It using the artificial scheme locally thawed, is recycled in frigo using hot salt brine, melts the frozen soil around freezing pipe；
(2), salt water heats:
With a 3m3The brine tank of left and right stores salt water, carries out heating salt water with the heating wire of six groups of 20kw, temperature is controlled 75
±10℃；
(3), brine recycling:
Brine recycling flow control using brine pump circulating brine, Model of pump IS150-125-315, each freezing hole exists
5-7m3/h；
(4), it thaws and measures:
Using the thermometer hole in freezing curtain, the variation of daily Timing measurement curtain temperature, until freezing curtain rises to positive temperature
Until, then stop defrosting operation；
(5), freezing pipe rises and pulls out:
After freezing pipe thaws, interior salt water discharge will be managed with compressed air, examination is carried out using crane and is pulled out, when pulling up 0.5m or so, really
Protect it is without exception after, quickly extract freezing pipe, tube drawing pays attention to freezing pipe and hook wants being aligned, and freezing pipe cannot sprain strength, when tube drawing
Often micro- rotation freezing pipe is wanted, freezing pipe cannot pull out firmly, when such as pulling out motionless, hot salt brine defrosting be continued cycling through, until jelly can be pulled up
Until tying pipe.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110735439A (en) * | 2019-10-28 | 2020-01-31 | 中煤科工集团重庆研究院有限公司 | vertical hole tree-shaped freezing wall freezing method |
| CN112030938A (en) * | 2020-09-03 | 2020-12-04 | 海南大学 | Artificial stratum freezing system and method adopting combined refrigeration of liquid nitrogen and saline water |
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| CN105926636A (en) * | 2016-05-13 | 2016-09-07 | 中国矿业大学 | Freezing bottom-sealing construction method for deep foundation pit |
| WO2018113488A1 (en) * | 2016-12-20 | 2018-06-28 | 中国十七冶集团有限公司 | Pipe jacking and freezing system and construction method thereof |
| CN108797601A (en) * | 2018-06-13 | 2018-11-13 | 王海霖 | A kind of construction method of piled anchor and liquid nitrogen frozen soil wall composite support system |
| CN210049225U (en) * | 2019-05-14 | 2020-02-11 | 海南大学 | Foundation pit bottom freezing and reinforcing structure |
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| CN204418200U (en) * | 2015-01-30 | 2015-06-24 | 海南大学 | One freezes cement mixing method |
| CN205260038U (en) * | 2016-01-05 | 2016-05-25 | 海南大学 | Wall reinforced structure is freezed to shield tunnel end box |
| CN105926636A (en) * | 2016-05-13 | 2016-09-07 | 中国矿业大学 | Freezing bottom-sealing construction method for deep foundation pit |
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| CN112030938A (en) * | 2020-09-03 | 2020-12-04 | 海南大学 | Artificial stratum freezing system and method adopting combined refrigeration of liquid nitrogen and saline water |
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