Background technology
China builds dam since the seventies in karst area, and it is big to build Facing Hydraulic Project two in karst area
Problem, when applicable, efficient, the accurate investigation way of selection, to find out karst engineering geological condition;Second, selected according to condition
Economical rationality, the ground of technical feasibility and based process method.By the solubility of particularity-carbonate of Karst Geological Landscape is made
Into solution cavity, it is molten collapse body and complexity Buried Pipeline Network Systems, survey difficulty, funds and the cycle of work with not only increasing, more increase
The big difficulty and complexity of basement process, have using displacement, grouting to karst strata processing, play bored concrete pile, rotary churning pile, steel pipe
The methods of stake.
Strong karsts developing area stratum refers to there is major fault, the rock stratum of cavern development under normal circumstances, in strong corrosion section
Occur rock stratum of the no pressure without the large seepage phenomenon such as overfall in grouting construction.Curtain Grouting Construction is mainly deposited on the stratum
In following construction technology difficult point:(1) because grouting works amount is big, the grouting material of consumption is more, and construction is complicated, and construction lasts
Long, therefore, the cost of curtain is high.(2) injection rate is big during the Curtain Grouting Construction on strong karsts developing area stratum, and hole section fills number again
More, grouting lasts length, is constructed using bore hole-top-enclosed grouting method.The major defect of bore hole-top-enclosed grouting method is in perfusion underflow
When time is long, grout pipe is easily clogged in hole by cement.Particularly when irrigating deep hole, grout pipe is very long, and slurries glue in hole
Thick, careless slightly, grout pipe may be cast extremely by grout cures, cause hole event.(3) often met during strong karst curtain drilling construction
To full-filling type solution cavity, charges are yellow mud sand.When shallow-layer meets full-filling type solution cavity, the punching of big flow water can be used to advance and rushed
Wash, abrasive band most in hole is portalled outer, so as to reach the purpose of pore-forming.In deep layer, because the ratio of sand is great, using big
When flow water is rinsed, the water flow pressure of pump output can only portal minimal amount of abrasive band outside, and substantial amounts of sand is remained in hole,
So collapse can not pore-forming for the sand in trip-out metapore.And when carrying out deep layer full-filling solution cavity section drilling, because water pressure of cooling water is small,
When down creeping into, the silt particle in hole can enter in drilling rod rig, block drilling rod, cause cooling water not circulate, burn
The phenomenon of brill.(4) geological condition of karst area is changeable, and solution cavity, corrosion fissure are also frequently encountered during grouting construction,
Occur when being mainly shown as drilling in work progress occurring when drilling depth quickening, collapse hole, leak, water burst and grouting in brill, drilling
Injection rate is big and repeatedly multiple fill still is unable to reach the anomalies such as ending standard.
Application for a patent for invention Publication No. CN 103485345 discloses a kind of coating orifice closing high pressure grout curtain
Construction method, it comprises the following steps:(1) non-grout compartment construction;(2) grout compartment pore-creating;(3) grout compartment length division;(4) it is in the milk
Pressure determines;(5) grouting method determines.For the present invention using sleeve pipe with proceeding to non-grout compartment, slurry strengthened wall pore-creating can be greatly
Penetration rate and one-tenth porosity are improved, the pore-forming difficult problem for solving deep covering layer stratum;In deep covering layer using high
Grouting pressure, grouting injection rate substantially increase, dilation angle increase, and grouting effect is good;Orifice closing curtain is used in coating
Curtain grouting construction engineering method, grouting quality is guaranteed, and has substantially solved thing in " holding tube " hole often occurred in filling process
Therefore improve efficiency of construction.The patent only illustrates the pore-forming of coating high pressure grout curtain, grouting method, without reference to locating
The karst treatment that drilling runs into is managed, also the no and specific grouting treatment method for different types of karst.
The content of the invention
In view of the shortcomings of the prior art, the present invention provides a kind of strong karsts developing area stratum Curtain Grouting Construction method, it includes
Following steps:
(1) pore-forming
When filling-type Karst cave or corrosion fissure are run into filling process, by combine high pressure water washing replace pore-forming or
Drilled using grouting pump injection cooling water, 1.5g/cm is backfilled after going out3Cement mortar;
(2) division grouting segment length
The a length of 5m of grout compartment, during rock crushing hole wall shakiness, grouting segment length foreshortens to 2~3m, concrete structure and basement rock
The grout compartment segment length of contact position is 2m;
(3) controlled grouting pressure
Using aperture overfall pressure as standard, Stress control is in 3.0~5.0MPa;
(4) grouting method is determined
" orifice closing, from top to bottom stages cycle " grouting method is taken, it comprises the following steps:
1) grouting uses high-pressure grouting pump, is supported the use with grouting automatic recording instrument;
2) cement mortar converts step by step than level by dilute to dense, and water is 3 with grey mass ratio:1、2:1、1:1、0.8:1 and 0.5:1
Five than level, the water being in the milk and gray scale are 3:1.
Further, described in step (1) joint high pressure water washing displacement hole creating technology the step of be:Adjacent holes is equal
The same elevation of solution cavity section is got into, holes carries out high pressure water washing processing simultaneously, gangs up holes, the sand content in water to be returned
Terminate when less, without mud;The drilling rod in a hole is taken out, the aperture in another hole is closed, it is simultaneously right with two grouting pumps
There is in the hole of drilling rod a progress high pressure water washing, the Stress control of the water under high pressure is in 3.0MPa, the hole of silt particle never drilling rod
Inside go out.
Further, step (4) the determination grouting method, filling-type Karst cave or corrosion fissure grouting method are as follows:
(1) it is 3 by water and gray scale:1 cement mortar opens filling, and the value shown on the pressure gauge according to grouting pipe-line control valve is entered
Row control, flow is more than 30L/min when slurries convert the ratio level reached big slurry filling or injection drying loss amount exceedes
500kg/m, irrigated using cement and flyash mixed serum, and handled by following measures:
1) the big duty pressure that shows declines 20% on the pressure gauge of grouting pipe-line control valve, irrigates l hours, if pressure or
Injection rate is unchanged, then reduces the 20% of current pressure, after irrigating l hours, if pressure or injection rate are unchanged, that is, and 8h to be coagulated;
Filled again after solidifying, the pressure or injection rate after multiple filling and treat it is solidifying before it is close, that is, use instead and wait that the cement before coagulating mixes with flyash
Slurry filling;Pressure or injection rate after multiple filling change with waiting compared with before coagulating, then using 3:1 water and the cement of gray scale
Slurry perfusion, by interval 0.5MPa classification boostings;Implement the pressure after multiple fill and be less than 1MPa, then sand perfusion is mixed using cement mortar, directly
Reach to grouting pressure and l.0MPa wait to coagulate afterwards, time 8h to be coagulated;
2) the big duty pressure shown on the pressure gauge of grouting pipe-line control valve declines 20%, irrigates l hours, pressure occurs
Rise or injection rate have the situation of reduction, continue to irrigate, until terminating, avoid waiting to coagulate.
Further, step (4) the determination grouting method, no filling or half packed type corrosion fissure grouting method are such as
Under:
(1) if grouting when do not return slurry and corrosion fissure it is big, using grout pouring;If not returning slurry and corrosion fissure hour,
Sand perfusion is mixed using cement mortar, until overfall and pressure >=1MPa, time to be coagulated are not less than 8h;
(2) if returning slurry and pressure >=1MPa, there is overfall, fully circulated beneficial in hole, open filling use water and gray scale for
3:1 cement mortar, slurries are carried out according to code requirement and are converted into the slurries bigger than level, when injection rate is more than 30L/min or list
Position injection drying loss amount is irrigated using cement and flyash mixed serum more than 500kg/m, irrigates 7.5~10t dry ash amounts first
Afterwards, the time to be coagulated is not less than 8h;
(3) filled again after solidifying, use water with gray scale for 3:1 cement mortar, the phase before pressure and injection rate occur and waiting to coagulate
Closely, that is, use instead treat it is solidifying before cement irrigated with flyash mixed serum, irrigated in the case where there is overfall dry ash amount 7.5~
After l0t, waterglass perfusion is filled by the following method and the time to be coagulated is not less than 8h:
1) grout injection and waterglass mixed serum;
2) separately irrigated using waterglass and cement mortar, first irrigate 200L waterglass, Reperfu- sion is than level 0.5:1 cement mortar
400L;
(4) in filling process, in the case of pressure rise, it is classified and boosts by 0.5MPa.
Further, the grouting method of step (4) the determination grouting method, no filling or half filling-type Karst cave is as follows:
(1) solution cavity is small, falls to bore below 0.5m, mixes sand using cement mortar, using aperture plus sand, mixes sand amount by cement amount
50%th, 70%, l00% perfusions, handled using following methods after overfall to appear:
1) after there is overfall, irrigated using cement and flyash mixed serum, dry ash amount fills water glass up to after 7.5~10t
Glass irrigates, and the time to be coagulated is not less than 8 hours;
2) filled again after solidifying, use water with gray scale for 3:1 cement mortar, occur pressure and injection rate with treat it is solidifying before it is close, i.e.,
Use the grout pouring for treating solidifying preceding water and gray scale instead;When there is overfall, irrigated with 7.5~10t of dry ash amount admixture waterglass, wait to coagulate
Not less than 8 hours;
(2) solution cavity is big, falls and bores more than 0.5m, expands aperture, backfills self-compacting concrete or flowing concrete, or use
Rubble exchanges backfill with concrete, after backfilling saturation, then is irrigated, and uses cement mortar or cement and flyash mixing slurry.
Further, the cement and flyash mixed serum, water:Concrete and coal ash=0.5:1~0.7:1;Flyash
Volume is the 20%~30% of cement weight;Cement mortar mixes sand, mix sand amount generally by the 10% of cement amount, 20%, 30%,
40%th, 50%, 70% or 100%.
Compared with prior art, the beneficial effects of the present invention are:
Construction method of the present invention, using the innovation skill such as " high pressure washing replacement technique ", " sand return technology " in construction
Art, solve the hole creating technology problem of Infra-karst development stratum grout curtain, engineering is smoothly implemented;According to different ground
Matter condition, the viscosity of slurries, shearing force and modeling are adjusted by filling various admixtures and chemical treatments in cement mortar
Variable element, it is subject to certain perfusion measure and means, so as to control the injection rate of slurries and diffusance, can not only reaches optimal
Grouting effect, it can also reduce the unnecessary loss of slurries.
Embodiment
In order to make the purpose , technical scheme and advantage of the present invention be clearer, with reference to embodiments, to the present invention
It is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, it is not used to
Limit the present invention.
The Specific construction technological process of pass reservoir is as follows
1st, overall construction technology process
Strong karsts developing area stratum grout curtain uses orifice closing, is circulated in hole, packer grouting from top to bottom, per work order
The overall construction technology process of grouting in member is constructed according to the sequence of first downstream row → upstream row → intermediate row, with adjacent elder generation in row
Sequence hole can construct postorder hole after having constructed.Operational procedure:Clear up the installation of job site → measurement discharge hole position → construction platform and
→ rig alignment leveling anchors → is checked and accepted (domatic) to lift hole drilling → installation and lift deformation observing device (and test) → guide
Construct → III sequence hole construction → inspection hole construction in the sequence hole of hole → I → II sequence hole of constructing.
2nd, single hole construction technology process
Rig centering hole position → leveling fixation rig → first paragraph pore-creating → gaging hole depth, hole deviation → lower disabler → hole flushing →
Press water → grouting → lower orifice tube, 72h coagulate → second segment pore-creating → gaging hole depth, hole deviation → hole flushing → pressure water → grouting →... the
Water → whole hole section grouting → mechanical sealing of hole → artificial sealing of hole is pressed in five sections of pore-creating → odd number section deviational survey →... complete opening is checked and accepted →.
3rd, Mortar mix proportion
3.1st, the water of cement mortar and gray scale use 3:1、2:1、1:1、0.8:1、0.5:1 five, than level, are opened filling and use 3:1
The grout pouring of water and gray scale;
3.2nd, supplementary cementitious material, additive etc. need to be added being in the milk in slurries, grouting slurries are tests determined, using with
It is as follows to close weight ratio:
Water:Concrete and coal ash=0.5:1~0.7:1;
Doping quantity of fly ash is the 20%~30% of cement weight;
Bentonite volume is the 1% of cement weight, and plasticiser volume is the 1.0~1.2% of cement weight;
Cement paste is prepared according to water burst traffic conditions in crack size and hole.
4th, grouting segment length and pressure
Grouting segment length is generally 5m, and during rock crushing hole wall shakiness, grouting segment length foreshortens to 2~3m, concrete structure with
The grout compartment segment length of basement rock contact position is 2m.
Using aperture overfall pressure as standard, Stress control is in 3.0~5.0MPa.
5th, ending standard
5.1st, under design pressure, when grouting injection rate is not more than 1.0L/min, Continuous Perfusion 60min.
5.2nd, grout curtain end hole section permeability rate is more than the permeability rate standard of design requirement or unit injection rate is more than
During 100kg/m, drilling should continue to deepen, and deepen segment length 5m every time, at most deepen 3 sections, count 15m.
6th, the grout construction method of abnormal type of karst or karst exception hole section
Mainly there is following type of karst or karst exception hole section in strong karsts developing area stratum grout curtain:(1), packed type
Solution cavity or corrosion fissure;(2), without filling or half packed type corrosion fissure;(3), without filling or half filling-type Karst cave;(4), collapse hole
Or water burst.
6.1st, the filling-type Karst cave or corrosion fissure grouting method are as follows:
(1) open filling and use 3:1 water and the grout pouring of gray scale, shown according to being in the milk on the pressure gauge of pipe-line control valve
Value be controlled, flow is more than 30L/min during the ratio level that reaches of slurries conversion big slurry filling or injection drying loss amount surpasses
500kg/m is crossed, is irrigated using the mixed serum of cement and flyash, and handled by following measures:
1) the big duty pressure that shows declines 20% on the pressure gauge of grouting pipe-line control valve, irrigates l hours, if pressure or
Injection rate is unchanged, then reduces the 20% of current pressure, after irrigating l hours, if pressure or injection rate are unchanged, that is, and 8h to be coagulated;
Filled again after solidifying, the pressure or injection rate after multiple filling and treat it is solidifying before it is close, that is, use instead and wait that the cement before coagulating mixes with flyash
Slurry filling;Pressure or injection rate after multiple filling change with waiting compared with before coagulating, then using 3:1 water and the cement of gray scale
Slurry perfusion, by interval 0.5MPa classification boostings;Implement the pressure after multiple fill and be less than 1MPa, then sand perfusion is mixed using cement mortar, directly
Reach to grouting pressure and l.0MPa wait to coagulate afterwards, time 8h to be coagulated;
2) the big duty pressure shown on the pressure gauge of grouting pipe-line control valve declines 20%, irrigates l hours, pressure occurs
Rise or injection rate change, and continue to irrigate, until terminating, avoid waiting to coagulate.
6.2nd, it is described as follows without filling or half packed type corrosion fissure grouting method:
(1) if grouting when do not return slurry and corrosion fissure it is big, using grout pouring;If not returning slurry and corrosion fissure hour,
Sand perfusion is mixed using cement mortar, until overfall and pressure >=1MPa, time to be coagulated are not less than 8h;
(2) if returning slurry and pressure >=1MPa, there is overfall, fully circulated beneficial in hole, be 3 by water and gray scale:1 water
Mud opens filling, and carrying out slurries according to code requirement is converted into the slurries bigger than level, when injection rate is more than 30L/min or unit note
Enter drying loss amount more than 500kg/m, irrigated using cement and flyash mixed serum, after irrigating 7.5~10t dry ash amounts first, treated
The solidifying time is not less than 8h;
(3) filled again after solidifying, use water with gray scale for 3:1 cement mortar, the phase before pressure and injection rate occur and waiting to coagulate
Closely, that is, use instead treat it is solidifying before cement irrigated with flyash mixed serum, irrigated in the case where there is overfall dry ash amount 7.5~
After l0t, waterglass perfusion is filled by the following method and the time to be coagulated is not less than 8h:
1) grout injection and waterglass mixed serum;
2) separately irrigated using waterglass and cement mortar, first irrigate 200L waterglass, Reperfu- sion is than level 0.5:1 cement mortar
400L;
(4) in filling process, in the case of having pressure rise, it is classified and boosts by 0.5MPa.
6.3rd, the grouting method without filling or half filling-type Karst cave is as follows:
(1) solution cavity is small, falls to bore below 0.5m, mixes sand using cement mortar, using aperture plus sand, mixes sand amount by cement amount
50%th, 70%, l00% perfusions, handled using following methods after overfall to appear:
1) after there is overfall, irrigated using cement and flyash mixed serum, dry ash amount fills water glass up to after 7.5~10t
Glass irrigates, and the time to be coagulated is not less than 8 hours;
2) filled again after solidifying, use water with gray scale for 3:1 cement mortar, occur pressure and injection rate with treat it is solidifying before it is close, i.e.,
Use the grout pouring for treating solidifying preceding water and gray scale instead;When there is overfall, irrigated with 7.5~10t of dry ash amount admixture waterglass, wait to coagulate
Not less than 8 hours;
(2) solution cavity is big, falls and bores more than 0.5m, expands aperture, backfills self-compacting concrete or flowing concrete, or use
Rubble exchanges backfill with concrete, after backfilling saturation, then is irrigated, and uses cement mortar or cement and flyash mixing slurry.
6.4th, collapse hole, the construction method of water burst hole section are met
(1) collapse hole
Collapse hole section should shorten segment length's perfusion if soft stratum (such as clay), broken rock according to actual conditions.
Collapse hole section should determine segment length, usually 2m, is rushed using clear water if layer of sand according to collapse hole situation and sand layer thickness
Wash, irrigated after returning water cleaning using neat slurry, avoid being fed into cement mortar.
(2) water burst hole section
1) there is the hole section of water burst, needing to survey note water burst pressure and flow before grouting, shortening segment length, increasing grouting by taking
Slurry tail pipe tripping in hole section perfusion is penetrated in pressure, the perfusion of pure pressure type, pvc pipe replacement, admixture accelerator, is extended lasting grouting time and is treated
The control measure such as time are coagulated to ensure the construction quality effect of such grout hole.
2) in filling process, a concentration of slurry is determined every 10~15min.When finding that overfall thickens, should strengthen starching
The frequency of liquid Concentration Testing, and form record.When overfall thickens, grouting should use the new slurry that identical water is with gray scale instead and be filled
Note, if DeGrain, continue perfusion 30min, that is, stop grouting.
3) grouting pressure is improved;Improve ending standard, it is necessary to screen slurry is carried out more than 4 hours, to check water burst;Water burst does not stop
When only, using the means of supplementing out economy of the slurry as screen slurry are closed, close to starch and wait to coagulate 24~48 hours.
6.5th, the continuity of grouting is kept in work progress, avoids arbitrarily interrupting, once interrupting, to recover to be in the milk in time,
Pass Base of Dam of Reservoir belongs to typical karst landform, is excavated by adit, seepage proof curtain guide hole drilling and electromagnetism
The means such as ripple CT detections are verified seepage prevention of dam founda line position stratum karst and extremely developed, and wherein right bank and riverbed line rate of karstification are high respectively
Up to 20.90% and 31.32%, and based on being filled with silty clay.Wherein:The ∈ 3m stratum of river-bed section are developed the most, mainly
Distribution elevation is 470~380m, and distributed depth is up to more than 100 meters, and with less than based on 3m height.Right bank develops multiple solution cavities or molten
Hole group, maximum cavity volume are more than 40,000 m3.Pass reservoir arranges seepage proof curtain, antiseepage in three layers of grouting adit of left and right banks
The curtain long 1383m of body, quantities is 150,000 m, maximum grouting pressure 3.5MPa, maximum hole depth 201.37m.Xiushan Mountain pass reservoir engineering
Using above-mentioned construction method, engineering is possessed water storage condition on schedule, calculate and analyze by financial cost, reduce engineering cost
10000000 yuan, shorten 8 months completions time of project, remarkable in economical benefits.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all essences in the present invention
All any modification, equivalent and improvement made within refreshing and principle etc., should be included in the scope of the protection.