CN111036660A - In-situ curing method for heavy metal polluted sandy gravel soil layer - Google Patents
In-situ curing method for heavy metal polluted sandy gravel soil layer Download PDFInfo
- Publication number
- CN111036660A CN111036660A CN201911421565.6A CN201911421565A CN111036660A CN 111036660 A CN111036660 A CN 111036660A CN 201911421565 A CN201911421565 A CN 201911421565A CN 111036660 A CN111036660 A CN 111036660A
- Authority
- CN
- China
- Prior art keywords
- grouting
- situ
- curing agent
- double
- slurry
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000001723 curing Methods 0.000 title claims abstract description 64
- 238000011065 in-situ storage Methods 0.000 title claims abstract description 53
- 239000002689 soil Substances 0.000 title claims abstract description 29
- 229910001385 heavy metal Inorganic materials 0.000 title claims abstract description 20
- 238000005553 drilling Methods 0.000 claims abstract description 52
- 239000002002 slurry Substances 0.000 claims abstract description 40
- 238000000034 method Methods 0.000 claims abstract description 24
- 238000007711 solidification Methods 0.000 claims abstract description 22
- 230000008023 solidification Effects 0.000 claims abstract description 22
- 239000002131 composite material Substances 0.000 claims abstract description 18
- 239000003795 chemical substances by application Substances 0.000 claims description 36
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 28
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 claims description 15
- ZCCIPPOKBCJFDN-UHFFFAOYSA-N calcium nitrate Chemical compound [Ca+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ZCCIPPOKBCJFDN-UHFFFAOYSA-N 0.000 claims description 14
- 239000011575 calcium Substances 0.000 claims description 13
- 229910052742 iron Inorganic materials 0.000 claims description 12
- 239000007788 liquid Substances 0.000 claims description 12
- 239000004576 sand Substances 0.000 claims description 12
- 239000000440 bentonite Substances 0.000 claims description 11
- 229910000278 bentonite Inorganic materials 0.000 claims description 11
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 claims description 11
- 239000004570 mortar (masonry) Substances 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- 230000015572 biosynthetic process Effects 0.000 claims description 10
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 9
- 229910052791 calcium Inorganic materials 0.000 claims description 9
- 239000004568 cement Substances 0.000 claims description 9
- 239000004115 Sodium Silicate Substances 0.000 claims description 8
- 229910052911 sodium silicate Inorganic materials 0.000 claims description 8
- 239000002245 particle Substances 0.000 claims description 7
- 235000019353 potassium silicate Nutrition 0.000 claims description 7
- 150000001875 compounds Chemical class 0.000 claims description 6
- 230000002787 reinforcement Effects 0.000 claims description 5
- 239000011790 ferrous sulphate Substances 0.000 claims description 4
- 238000011049 filling Methods 0.000 claims description 4
- 229910000359 iron(II) sulfate Inorganic materials 0.000 claims description 4
- 235000003891 ferrous sulphate Nutrition 0.000 claims description 3
- 239000012530 fluid Substances 0.000 claims description 3
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical group [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 16
- 238000010276 construction Methods 0.000 abstract description 11
- 239000006185 dispersion Substances 0.000 abstract description 7
- 238000002347 injection Methods 0.000 abstract description 5
- 239000007924 injection Substances 0.000 abstract description 5
- 238000005067 remediation Methods 0.000 abstract description 4
- 238000004458 analytical method Methods 0.000 abstract description 3
- 238000009826 distribution Methods 0.000 abstract description 3
- 239000000463 material Substances 0.000 description 14
- 230000006872 improvement Effects 0.000 description 11
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 9
- 239000002956 ash Substances 0.000 description 9
- 238000005755 formation reaction Methods 0.000 description 8
- 230000008569 process Effects 0.000 description 7
- 238000005520 cutting process Methods 0.000 description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 229910052785 arsenic Inorganic materials 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 239000003344 environmental pollutant Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 231100000719 pollutant Toxicity 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 230000008439 repair process Effects 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 2
- 239000011398 Portland cement Substances 0.000 description 2
- 235000011941 Tilia x europaea Nutrition 0.000 description 2
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 239000003814 drug Substances 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000004571 lime Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 239000011435 rock Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 1
- 229910020489 SiO3 Inorganic materials 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000000740 bleeding effect Effects 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- VSGNNIFQASZAOI-UHFFFAOYSA-L calcium acetate Chemical compound [Ca+2].CC([O-])=O.CC([O-])=O VSGNNIFQASZAOI-UHFFFAOYSA-L 0.000 description 1
- 239000001639 calcium acetate Substances 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- FUFJGUQYACFECW-UHFFFAOYSA-L calcium hydrogenphosphate Chemical compound [Ca+2].OP([O-])([O-])=O FUFJGUQYACFECW-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 230000009918 complex formation Effects 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 235000019700 dicalcium phosphate Nutrition 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 229960002089 ferrous chloride Drugs 0.000 description 1
- 239000010881 fly ash Substances 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 239000003349 gelling agent Substances 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- XLYOFNOQVPJJNP-ZSJDYOACSA-N heavy water Substances [2H]O[2H] XLYOFNOQVPJJNP-ZSJDYOACSA-N 0.000 description 1
- 229910052588 hydroxylapatite Inorganic materials 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- FBAFATDZDUQKNH-UHFFFAOYSA-M iron chloride Chemical compound [Cl-].[Fe] FBAFATDZDUQKNH-UHFFFAOYSA-M 0.000 description 1
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- XYJRXVWERLGGKC-UHFFFAOYSA-D pentacalcium;hydroxide;triphosphate Chemical compound [OH-].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O XYJRXVWERLGGKC-UHFFFAOYSA-D 0.000 description 1
- 239000002957 persistent organic pollutant Substances 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000005060 rubber Substances 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 229910021487 silica fume Inorganic materials 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000004083 survival effect Effects 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 238000012384 transportation and delivery Methods 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C1/00—Reclamation of contaminated soil
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C2101/00—In situ
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Soil Sciences (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
Abstract
The invention discloses an in-situ curing method for a heavy metal polluted sandy gravel soil layer, which comprises the following steps: selecting a pile machine drilling tool or a conical double-head spiral drilling tool according to the condition of the in-situ solidified pebble bed; grouting the composite slurry through grouting equipment; and (5) taking out and checking after grouting is finished. The method mainly acts on in-situ remediation of the polluted site, learns the distribution and pollution condition of the pebble bed through stratum analysis, and improves drilling equipment and grouting equipment so as to solve the technical problem of difficult drilling in the pebble bed by common in-situ injection; by detecting and analyzing the pollution indexes and the pollution condition of the pebble bed and selecting the slurry with anti-dispersion property to achieve a better solidification and cementation state, the technical problems that the solidification effect is poor and the cementation effect is difficult to form when the slurry is injected into the pebble bed in situ are solved; the in-situ curing method has important theoretical and practical significance for accumulating experience of in-situ curing construction of similar engineering.
Description
Technical Field
The invention relates to the technical field of pollution treatment, in particular to an in-situ curing method for a heavy metal polluted sandy gravel soil layer.
Background
With the deep development of urbanization and industrialization, soil, which is one of the necessary natural resources for human survival and development, faces an increasingly serious environmental safety problem. Heavy metal in the heavy metal contaminated soil mainly pollutes Cd, Zn, Pb, As and Hg, the heavy metal remained in the soil is difficult to eliminate because the heavy metal cannot be degraded by microorganisms, and can enter human bodies through underground water or food chains and the like, so that the human health is seriously influenced.
The in-situ solidification technology is a heavy metal polluted soil treatment technology which directly adds one or more exogenous substances into soil in a polluted area, changes the physicochemical property of the polluted soil through a series of reactions such as adsorption, precipitation, solidification and the like, reduces the mobility and bioavailability of heavy metals in the soil, and does not need to dig out or transport the polluted soil. The in-situ curing technology is increasingly applied to the heavy metal contaminated soil remediation engineering due to short period, quick response and stable effect.
In-situ solidification contaminated sites, repair of pebble beds is often involved in-situ solidification areas due to complex formations, whereas conventional in-situ solidification methods have difficulties in construction and formation of solidified bodies in the pebble beds. The sandy gravel stratum is a typical mechanically unstable stratum, has loose structure, no cementation and different sizes of gravel grain diameters, and has the characteristics of large internal friction angle of soil, poor plastic fluidity, large permeability coefficient and poor stability. The presence of the sandy gravel layer adds difficulty to the site where in situ disposal is required.
The in-situ curing operation mainly comprises the following procedures: selection, configuration (slurry or paste, dry material), delivery, mixing and stirring of the curing agent and the target pollution medium. In the in-situ curing, ordinary cement is usually selected as curing slurry; the reason is as follows: because of good grouting property, the grouting quantity and the grouting reinforcement range can be larger during grouting; the strength of the stone body is high, and the bearing capacity of the stratum can be effectively improved. However, the single-liquid cement slurry has poor dispersion resistance, is easy to be diluted by underground water, influences the strength and the water plugging performance, and is not suitable for being used under the conditions of rich water, high flow rate and high requirement on water plugging because of large shrinkage rate. In addition, it may be difficult to achieve leaching standards for certain heavy metal target contaminants by injection of cement alone. Therefore, in water-rich round gravel and pebble strata, the grouting slurry is required to have good bleeding performance and anti-dispersion performance, the composite slurry has the characteristics of high strength, high impermeability and wind dispersion resistance, a good cementing body is easily formed in the strata, the gelling time is controllable, and the operability is strong. In water-rich pebble and pebble formations, in order to ensure that the slurry is not diluted and washed away by underground running water, the slurry with relatively high viscosity is optimally used.
The curing agent has a great influence on the curing effect, and the curing agent materials are generally divided into cementing materials and adsorbing materials. Cementitious materials are the most common curing agents, primarily because of their low cost and availability. The cementing materials mainly comprise portland cement, fly ash, blast furnace slag, silica fume, cement kiln dust, various forms of lime, lime kiln dust and the like, wherein the portland cement is the most widely used curing agent so far. In addition, the additive with adsorption performance can improve the treatment effect of the solidification technology on heavy metals and semi-volatile organic pollutants, and comprises bentonite, activated carbon, phosphate, rubber particles, a gelling agent and the like.
The curing effect is obviously influenced by various parameters of the repairing equipment, and the curing effect mainly comprises effective action depth, stirring speed, medicament diffusion efficiency, treatment speed, stirring time and the like. Therefore, aiming at repairing the sandy gravel layer or the sandy gravel layer soil, it is necessary to improve the drilling machine and select proper grouting equipment and compound slurry.
Therefore, the method improves a drilling tool and a grouting device and provides a slurry proportion with good dispersibility based on the requirement of in-situ solidification of the pebble bed so as to solve the above difficulties.
Disclosure of Invention
Aiming at the problems of difficult drilling, difficult solidification and the like existing in the pebble stratum by the conventional common in-situ injection, the invention provides an in-situ solidification method for a heavy metal polluted sandy pebble soil layer.
The invention discloses an in-situ curing method for a heavy metal polluted sandy gravel soil layer, which comprises the following steps:
selecting a pile machine drilling tool or a conical double-head spiral drilling tool according to the condition of the in-situ solidified pebble bed; when the pebble layer is a stratum with sand, gravel soil and sand pebbles and the particle size of 2-15cm, selecting a pile machine drilling tool; when the pebble layer is a stratum with the particle size of sand and pebbles larger than 15cm, selecting a conical double-head spiral drilling tool;
grouting the composite slurry through grouting equipment; the grouting equipment comprises one or more of a double-liquid grouting pump and a double-cylinder mortar pump, the composite type slurry comprises water and ash, and the ash comprises bentonite, water glass and a curing agent;
and (5) taking out and checking after grouting is finished.
As a further improvement of the invention, the conical double-head spiral drilling tool comprises a bevel blade, a drill bit and a drill rod;
the oblique angle blade is installed on the lateral wall of drilling rod, the drill bit is installed the drilling rod tip, the drill bit is for adding the toper double-end auger bit that is equipped with closely knit nuclear.
As a further improvement of the invention, 1 double-liquid grouting pump and 2 double-cylinder mortar pumps are selected as grouting equipment, the grouting initial pressure of the grouting equipment is 0.5MPa, and the grouting termination pressure is 1.2 MPa.
As a further improvement of the invention, the double-liquid grouting pump is an KBY-50/70 type grouting pump, and the double-cylinder mortar pump is a HUB3.5A type double-cylinder mortar pump.
As a further improvement of the invention, the water-cement mass ratio of the composite slurry is 0.7:1, the bentonite accounts for 5% of the mass of the ash, and the water glass accounts for 5% of the mass of the ash.
As a further improvement of the present invention, the curing agent includes one or more of a calcium-based curing agent and an iron-based curing agent.
As a further improvement of the invention, the calcium-based curing agent is a compound curing agent of calcium nitrate and sodium silicate, the addition amount of the calcium nitrate is 0.5% of the mass of the ash material, and the addition amount of the sodium silicate is 1.5% of the mass of the ash material.
In a further improvement of the present invention, the iron-based curing agent is ferrous sulfate, and the addition amount of the iron-based curing agent is 1% of the mass of the ash material in terms of iron.
As a further improvement of the invention, in the grouting process, the grouting amount per unit volume needs to be calculated, and the calculation formula is as follows:
Q＝KαβV
wherein Q is the grouting amount per unit volume, K is the loss coefficient, α is the formation porosity, β is the formation filling coefficient, and V is the volume of the reinforcement.
As a further improvement of the invention, the core acceptance is as follows:
and (5) after grouting is finished, coring is started for 7d-15d, and coring is performed in a double-pipe single-hole mode by adopting a geological hectometer drilling machine.
Compared with the prior art, the invention has the beneficial effects that:
the method mainly acts on in-situ remediation of the polluted site, learns the distribution and pollution condition of the pebble bed through stratum analysis, and improves drilling equipment and grouting equipment so as to solve the technical problem of difficult drilling in the pebble bed by common in-situ injection; by detecting and analyzing the pollution indexes and the pollution condition of the pebble bed and selecting the slurry with anti-dispersion property to achieve a better solidification and cementation state, the technical problems that the solidification effect is poor and the cementation effect is difficult to form when the slurry is injected into the pebble bed in situ are solved; the in-situ curing method has important theoretical and practical significance for accumulating experience of in-situ curing construction of similar engineering.
Drawings
FIG. 1 is a flow chart of an in situ solidification method for heavy metal contaminated sandy gravel soil according to one embodiment of the present invention;
FIG. 2 is a schematic structural view of an improved pile driver drilling tool disclosed in an embodiment of the present invention;
FIG. 3 is a schematic diagram of the construction of the drill bit of FIG. 2;
FIG. 4 is a hydrogeological map of a plot as disclosed in one embodiment of the present invention;
FIG. 5 is a diagram illustrating in-situ solidification site placement and coring arrangement for a repair area according to an embodiment of the present invention;
fig. 6 is a diagram illustrating coring of a pebble bed according to an embodiment of the present invention.
In the figure:
21. a bevel blade; 22. a drill bit; 23. a drill stem; 24. fixing the bearing;
31. a pressure head; 32. a funnel-shaped crushing zone; 33. the core is compacted.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
The invention provides an in-situ curing method for a heavy metal polluted sandy gravel soil layer, which comprises the following steps: selecting a pile machine drilling tool or a conical double-head spiral drilling tool according to the condition of the in-situ solidified pebble bed; grouting the composite slurry through grouting equipment; and (5) taking out and checking after grouting is finished. The method mainly acts on in-situ remediation of the polluted site, learns the distribution and pollution condition of the pebble bed through stratum analysis, and improves drilling equipment and grouting equipment so as to solve the technical problem of difficult drilling in the pebble bed by common in-situ injection; by detecting and analyzing the pollution indexes and the pollution condition of the pebble bed and selecting the slurry with anti-dispersion property to achieve a better solidification and cementation state, the technical problems that the solidification effect is poor and the cementation effect is difficult to form when the slurry is injected into the pebble bed in situ are solved; the in-situ curing method has important theoretical and practical significance for accumulating experience of in-situ curing construction of similar engineering.
The invention is described in further detail below with reference to the attached drawing figures:
as shown in fig. 1, the present invention provides an in-situ solidification method for heavy metal contaminated sandy gravel soil layer, comprising:
step 1, selecting a pile machine drilling tool or a conical double-head spiral drilling tool according to the condition of an in-situ solidified pebble bed; the method specifically comprises the following steps:
when the pebble layer is a stratum with the grain size of 2-15cm and is sandy soil, gravel soil and sand pebbles, selecting an improved pile machine drilling tool shown in figure 2; as shown in fig. 2 and 3, aiming at the characteristic that the traditional drilling machine can only work in a soft soil or sandy soil geological structure, the drilling machine of the invention adds a conical double-head spiral drill bit 22 with a compact core 33 at the front end of a drill rod of the traditional drilling machine, and increases the crushing function of hard lithologic structures such as large pebbles; the improvement of the stirring blade is that the conventional horizontal blade structure is changed into an oblique angle blade 21 through angle adjustment, and the effect of re-cutting and upward material conveying is improved for the drill cuttings crushed by the conical auger at the front end. Wherein, the drilling rod 23 is the central axis of the whole structure, the top of the lower end thereof is the auger bit 22, the blade 21 at the middle upper part is the cutting and the transmission of the drill cuttings which are powerfully crushed by the auger bit 22, and the fixed bearing 24 is the fastening structure which connects the blade 21, the drill bit 22 and the drilling rod 23. The improved drilling tool is suitable for hard strata such as pebble strata, strongly weathered rock strata and the like. The method is characterized in that the power of a power head of the pile machine is increased, a drill bit and blades of the pile machine are improved, the improved drill bit is used for drilling and cutting a pebble layer in situ, and slurry is injected into the pebble layer at the end part of the drill bit to form a cement-soil solidified body, the strength of the solidified body is stably improved along with the continuous ash caking reaction, and the strength of the solidified body in the pebble layer can be improved to be more than 0.5-1 MPa.
When the pebble layer is a stratum with the particle size of sand and pebbles larger than 15cm, selecting a conical double-ended spiral drilling tool as shown in fig. 3, wherein fig. 3 is a schematic diagram of a compact core 33 of a pressure head 31 in the conical double-ended spiral drilling tool acting on a funnel-shaped crushing area 32; and (3) drilling broken pebbles, fishing rock debris by using a single-chassis or double-chassis spiral digging drilling bucket, basically fishing out the bottoms of the holes, drilling by using a spiral drill bit, and circulating the steps. The cone-type spiral drill bit is selected to have a higher drilling speed than the flat-bottom spiral drill bit because of the strong drilling stability of the cone-type spiral drill bit.
The two drilling tools have the advantages of high construction speed, simple construction process and high grouting speed; the construction capability is strong, and the maximum effective construction depth can reach 55 m. In addition, the method has the advantages of environmental protection and energy conservation, has no pollution in the construction process and low noise, and is a green construction method.
Step 2, grouting the composite slurry through grouting equipment; specifically, the method comprises the following steps:
the grouting equipment comprises one or more of a double-liquid grouting pump and a double-cylinder mortar pump, and preferably 1 double-liquid grouting pump and 2 double-cylinder mortar pumps, wherein the double-liquid grouting pump is an KBY-50/70 type grouting pump, and the double-cylinder mortar pump is a HUB3.5A type double-cylinder mortar pump. The initial pressure of the grouting is generally 0.5MPa, and the final pressure is1.2MPa, the grouting amount is kept at 0.40m3And/m. The composite grouting material grouting test shows that the field grouting pressure can reach the designed grouting pressure, and the grouting amount is controllable.
The composite slurry comprises water, ash bentonite, water glass and a curing agent; the compound slurry ratio is shown in table 1.
TABLE 1
The preparation method of the composite slurry comprises the following steps:
1) the preparation of the composite slurry needs to calculate the dosage of the bentonite according to the mixing proportion, and then a special swelling tank is adopted to swell the bentonite for 24 hours;
2) when the composite slurry is stirred, firstly, the swelled bentonite slurry is put into a grouting barrel, then, cement is added according to the proportion, the mixed liquid of the cement and the bentonite is forcibly stirred for 3min, then, water glass is added, and then, the slurry can be grouted after being forcibly stirred for 3-5 min.
3) In the grouting implementation process, the control of the grouting amount of the round gravel and the pebble layer is taken as the main part, and the grouting pressure is controlled within 1.2 MPa; the control of grouting pressure is mainly used in the silt and sand layers, and grouting can be stopped when the grouting pressure reaches the design requirement; when the grouting pressure does not meet the design requirement and the grouting amount meets the design requirement, the grouting can be stopped.
The composite slurry can be selected from corresponding curing agents according to requirements, and the main materials include the following types:
1) calcium-based curing agent: calcium hydroxide (Ca (OH)2Calcium acetate (Ca (CH)3COO)2·H2O), calcium hydrogen phosphate (CaHPO)4·2H2O), hydroxyapatite (Ca)5(PO4)3OH), anhydrous calcium chloride (CaCl)2) Calcium nitrate (Ca (NO)3)2)·4H2O。
2) Silicon-based compound material: sodium silicate (Na)2SiO3)·9H2O。
3) Iron-based curing agent: and alsoRaw iron powder (Fe), iron oxide (Fe)2O3Ferrous sulfate (FeSO)4)·7H2O), ferrous chloride (FeCl)2)·4H2O, iron (Fe) sulfate2(SO4) Iron chloride (FeCl)3)·6H2O。
Because the liquid curing agent has good permeability and is convenient for grouting, the liquid curing agent is used for curing the pebble layer. The liquid curing agent is a medicament with a better effect in a calcium-based curing agent and an iron-based curing agent respectively, the calcium-based solid curing agent is a compound curing agent of calcium nitrate and sodium silicate, and the addition amounts of the calcium-based solid curing agent and the sodium silicate are 0.5 percent and 1.5 percent respectively; ferrous sulfate is selected as the iron-based solid curing agent, and the addition amount is about 1 percent in terms of iron.
Therefore, the composite slurry has good grouting reinforcement effect and can form a better cementing body.
In the grouting process, the grouting amount of unit volume needs to be calculated, and the calculation formula is as follows:
Q＝KαβV
wherein Q is the grouting amount per unit volume, K is the loss coefficient and is generally 1.35, α is the formation porosity, β is the formation filling coefficient, V is the volume of the reinforcement body, and the grouting amount of the sand gravel layer is designed as shown in Table 2.
TABLE 2
| Formation classification | Diameter of the slip | Grouting amount/(m)3/m) | Filling rate | Remarks for note |
| Coarse sand layer | 1.5 | 0.3 | 0.2 | α＝0.35，β＝0.6 |
| Sand and gravel layer | 1.5 | 0.5 | 0.25 | α＝0.35，β＝0.8 |
And 3, performing core taking and acceptance inspection after grouting is completed.
And (5) after grouting is finished, coring is started for 7d-15d, and coring is performed in a double-pipe single-hole mode by adopting a geological hectometer drilling machine. In the coring process, the drilling speed of coring is slower because the strength of the cementing body is higher. The core sample taken out contains more cement gel, the slurry has better dispersion resistance, the slurry can be well cemented with the stratum, the strength is higher, and the coring effect can reach a more ideal state.
Example 1:
the invention provides an in-situ curing method for a heavy metal polluted sandy gravel soil layer, which comprises the following steps:
step 1, planning project implementation process according to the graph 1, wherein a case is located in a certain plot in Zhejiang lake city, the contamination depth of the plot is 6m, 2m-6m mainly comprises a pebble layer, the content of pebbles reaches 30% -65%, and the hydrogeological condition of the plot is shown in the graph 4; the particle size of the pebbles is 2-15cm, the conventional in-situ solidification method is difficult to implement, and therefore, a drilling tool after the drill bit 1 and the blades 2 are improved is selected for implementation.
And 2, carrying out grouting preparation by matching the drilling tool with a double-fluid grouting pump (KBY-50/70 type grouting pump (1), and a double-cylinder mortar pump (HUB3.5A type double-cylinder mortar pump 2).
And 3, selecting the composite slurry from the slurry according to the site pollution condition and the repair requirement, wherein the site target pollutants are nickel and arsenic.According to the slurry material proportion and the grouting parameters in the table 1, the admixture and the mixing amount comprise 5 percent of bentonite and 5 percent of water glass, and the calcium-based solid curing agent is a compound curing agent of calcium nitrate and sodium silicate, and the adding amounts are 0.4 percent and 1.6 percent respectively. The formation grouting amount is designed as shown in table 2, and the grouting amount of the sand-gravel layer is kept at 0.5m3/m。
And 4, starting grouting after the drilling tool, the grouting equipment and the slurry are selected. The grouting hole site arrangement is shown in FIG. 5; in order to verify the solidification effect, coring and sampling are respectively carried out on the solidified pebble layer after grouting for 0d, 7d, 10d and 15d, and the pebble layer coring sample is shown in fig. 6.
And 5, testing the core sample, wherein the test result is shown in a case parameter table in a table 3. Wherein, the arsenic pollutant is leached to reach the standard in the detection of the solidified 7d core sample, and the nickel pollutant is leached to reach the standard in the detection of the solidified 10d core sample.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. An in-situ solidification method for heavy metal contaminated sandy gravel soil layers, which is characterized by comprising the following steps:
selecting a pile machine drilling tool or a conical double-head spiral drilling tool according to the condition of the in-situ solidified pebble bed; when the pebble layer is a stratum with sand, gravel soil and sand pebbles and the particle size of 2-15cm, selecting a pile machine drilling tool; when the pebble layer is a stratum with the particle size of sand and pebbles larger than 15cm, selecting a conical double-head spiral drilling tool;
grouting the composite slurry through grouting equipment; the grouting equipment comprises one or more of a double-liquid grouting pump and a double-cylinder mortar pump, the composite type slurry comprises water and ash, and the ash comprises bentonite, water glass and a curing agent;
and (5) taking out and checking after grouting is finished.
2. The in situ curing method of claim 1, wherein the tapered double-ended auger comprises angled blades, a drill bit, and a drill stem;
the oblique angle blade is installed on the lateral wall of drilling rod, the drill bit is installed the drilling rod tip, the drill bit is for adding the toper double-end auger bit that is equipped with closely knit nuclear.
3. The in-situ curing method of claim 1, wherein 1 two-fluid grouting pump and 2 two-cylinder grouting pumps are selected as the grouting equipment, the grouting starting pressure of the grouting equipment is 0.5MPa, and the grouting ending pressure is 1.2 MPa.
4. The in situ cure method of claim 1, wherein the two-fluid grouting pump is a KBY-50/70 type grouting pump and the two-cylinder grouting pump is a HUB3.5A type two-cylinder grouting pump.
5. The in-situ curing method of claim 1, wherein the composite slurry has a water-cement mass ratio of 0.7:1, the bentonite accounts for 5% of the mass of the ash, and the water glass accounts for 5% of the mass of the ash.
6. The in situ curing method of claim 1 or 5, wherein the curing agent comprises one or more of a calcium-based curing agent and an iron-based curing agent.
7. The in-situ curing method of claim 6, wherein the calcium-based curing agent is a compound curing agent of calcium nitrate and sodium silicate, the addition amount of the calcium nitrate is 0.5% of the mass of the ash, and the addition amount of the sodium silicate is 1.5% of the mass of the ash.
8. The in-situ curing method according to claim 6, wherein the iron-based curing agent is ferrous sulfate, and the amount of the iron-based curing agent added is 1% by mass of the ash, calculated as iron.
9. The in-situ curing method of claim 1, wherein the grouting amount per unit volume is calculated during grouting by the formula:
Q＝KαβV
wherein Q is the grouting amount per unit volume, K is the loss coefficient, α is the formation porosity, β is the formation filling coefficient, and V is the volume of the reinforcement.
10. The in situ solidification method of claim 1, wherein the core acceptance is:
and (5) after grouting is finished, coring is started for 7d-15d, and coring is performed in a double-pipe single-hole mode by adopting a geological hectometer drilling machine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911421565.6A CN111036660A (en) | 2019-12-31 | 2019-12-31 | In-situ curing method for heavy metal polluted sandy gravel soil layer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911421565.6A CN111036660A (en) | 2019-12-31 | 2019-12-31 | In-situ curing method for heavy metal polluted sandy gravel soil layer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111036660A true CN111036660A (en) | 2020-04-21 |
Family
ID=70243344
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911421565.6A Pending CN111036660A (en) | 2019-12-31 | 2019-12-31 | In-situ curing method for heavy metal polluted sandy gravel soil layer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111036660A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101818647A (en) * | 2010-04-02 | 2010-09-01 | 中铁二局股份有限公司 | Advance support fast construction method in shallow tunnelling loose pebble bed |
| KR20110058472A (en) * | 2009-11-26 | 2011-06-01 | 한국지질자원연구원 | Tailings stabilization method by solidification layer formation |
| CN103266614A (en) * | 2013-05-15 | 2013-08-28 | 北京市政建设集团有限责任公司 | Sublevel retreating type two-fluid composite grouting construction method for deep foundation pit of sandy gravel stratum |
| CN105598154A (en) * | 2015-12-30 | 2016-05-25 | 北京高能时代环境技术股份有限公司 | Method for repairing soil polluted by arsenic |
| CN205840781U (en) * | 2016-08-08 | 2016-12-28 | 浙江绩丰岩土技术股份有限公司 | A kind of super three axes agitating pile of pebble layer |
-
2019
- 2019-12-31 CN CN201911421565.6A patent/CN111036660A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20110058472A (en) * | 2009-11-26 | 2011-06-01 | 한국지질자원연구원 | Tailings stabilization method by solidification layer formation |
| CN101818647A (en) * | 2010-04-02 | 2010-09-01 | 中铁二局股份有限公司 | Advance support fast construction method in shallow tunnelling loose pebble bed |
| CN103266614A (en) * | 2013-05-15 | 2013-08-28 | 北京市政建设集团有限责任公司 | Sublevel retreating type two-fluid composite grouting construction method for deep foundation pit of sandy gravel stratum |
| CN105598154A (en) * | 2015-12-30 | 2016-05-25 | 北京高能时代环境技术股份有限公司 | Method for repairing soil polluted by arsenic |
| CN205840781U (en) * | 2016-08-08 | 2016-12-28 | 浙江绩丰岩土技术股份有限公司 | A kind of super three axes agitating pile of pebble layer |
Non-Patent Citations (4)
| Title |
|---|
| 中国建筑学会建材分会混凝土外加剂应用技术专业委员会: "《聚羧酸系高性能减水剂及其应用技术新进展》", 31 May 2017, 北京理工大学出版社 * |
| 刘志强: "《竖井掘进机凿井技术》", 30 November 2018, 煤炭工业出版社 * |
| 焦胜军: "《高速铁路桥涵施工与维护》", 31 July 2017, 西南交通大学出版社 * |
| 王中华 等: "《油田化学品实用手册》", 31 July 2004, 中国石化出版社 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA3025709C (en) | In-situ injection of soil and groundwater - high pressure rotary jet grouting in-situ remediation system and method | |
| CN110512589B (en) | A kind of super soft foundation solidification method of super soft foundation with vacuum dewatering and drainage combined with magnesium oxide carbonization | |
| CN204898658U (en) | Be used for consolidating little biological glue knot sand pile of soft soil foundation | |
| CN106836186A (en) | A kind of construction technology of utilizing solidified earth from sludge | |
| CN100386484C (en) | a concrete pile | |
| CN108150179B (en) | Improvement method of shield tunneling pressure chamber dregs in high permeability complex strata | |
| CN104329020B (en) | A kind of reinforced long spire embedding rock construction equipment and technique thereof | |
| CN108316346B (en) | A green treatment method for abandoned underground shelters | |
| CN105484269B (en) | Foundation pit enclosure structure seepage prevention and treatment construction method under blasting condition | |
| CN108166994A (en) | A kind of construction method of grouting reinforced region applied to water-rich sand layer shield tunnel | |
| CN112206753A (en) | Hydrophilic polymer modified bentonite composite material and preparation method and application thereof | |
| Zhen et al. | Soil conditioning tests on sandy and cobbly soil for shield tunneling | |
| CN104018485A (en) | Bed course replacing and filling and carbonization reinforcing method of soft soil foundation | |
| CN107299633A (en) | A kind of utilization High-pressure Spiral Spray Technology improves the construction method of the bearing capacity of stake | |
| CN110512592B (en) | A kind of reinforcement treatment system for vacuum preloading and duct pile gas injection carbonization ultra-soft foundation | |
| CN104353666A (en) | In-situ stirring curing and repairing method for heavy metal polluted soil | |
| CN113174933A (en) | Microorganism-induced calcium carbonate precipitation gravel composite pile reinforcing structure and construction method | |
| CN104532817A (en) | Site mixing and blow-filling method of solidified dredged mud | |
| CN111036660A (en) | In-situ curing method for heavy metal polluted sandy gravel soil layer | |
| Ibragimov | Soil stabilization with cement grouts | |
| CN112195909A (en) | Method for reinforcing soft foundation of road and parking lot | |
| CN119244162A (en) | A 3D drill bit for cement mixing piles suitable for deep muddy soft soil layers near the river | |
| CN113062744B (en) | Method for improving water-rich sandy pebble stratum shield construction residue soil and shield construction method | |
| CN107975027A (en) | The construction method that shield launching is reinforced with reaching end soil body | |
| CN210087248U (en) | Double-pipe spiral drill bit for cast-in-situ cement soil composite foundation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200421 |