CN115450198B - Device for solidifying loess foundation through microorganism pressurization grouting and method for solidifying loess foundation - Google Patents
Device for solidifying loess foundation through microorganism pressurization grouting and method for solidifying loess foundation Download PDFInfo
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- CN115450198B CN115450198B CN202211349818.5A CN202211349818A CN115450198B CN 115450198 B CN115450198 B CN 115450198B CN 202211349818 A CN202211349818 A CN 202211349818A CN 115450198 B CN115450198 B CN 115450198B
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- 238000000034 method Methods 0.000 title claims abstract description 36
- 244000005700 microbiome Species 0.000 title claims description 20
- 239000002002 slurry Substances 0.000 claims abstract description 82
- 239000002689 soil Substances 0.000 claims abstract description 55
- 238000003860 storage Methods 0.000 claims abstract description 26
- 230000002787 reinforcement Effects 0.000 claims abstract description 23
- 238000005056 compaction Methods 0.000 claims abstract description 18
- 239000000463 material Substances 0.000 claims abstract description 18
- 241000234314 Zingiber Species 0.000 claims abstract description 16
- 235000006886 Zingiber officinale Nutrition 0.000 claims abstract description 16
- 235000008397 ginger Nutrition 0.000 claims abstract description 16
- 239000004575 stone Substances 0.000 claims abstract description 16
- 238000005516 engineering process Methods 0.000 claims abstract description 14
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 11
- 239000007788 liquid Substances 0.000 claims description 31
- 238000010276 construction Methods 0.000 claims description 27
- 239000000843 powder Substances 0.000 claims description 14
- 238000012360 testing method Methods 0.000 claims description 12
- 230000001580 bacterial effect Effects 0.000 claims description 10
- 230000000813 microbial effect Effects 0.000 claims description 10
- 239000000945 filler Substances 0.000 claims description 7
- 230000008569 process Effects 0.000 claims description 7
- 238000007569 slipcasting Methods 0.000 claims description 7
- 238000013461 design Methods 0.000 claims description 6
- 230000008595 infiltration Effects 0.000 claims description 6
- 238000001764 infiltration Methods 0.000 claims description 6
- 238000001514 detection method Methods 0.000 claims description 5
- 238000004140 cleaning Methods 0.000 claims description 3
- 230000008030 elimination Effects 0.000 claims description 3
- 238000003379 elimination reaction Methods 0.000 claims description 3
- 238000007711 solidification Methods 0.000 claims description 3
- 230000008023 solidification Effects 0.000 claims description 3
- 230000000694 effects Effects 0.000 description 13
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 6
- 229910000019 calcium carbonate Inorganic materials 0.000 description 3
- 238000007689 inspection Methods 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 230000003068 static effect Effects 0.000 description 3
- 201000010099 disease Diseases 0.000 description 2
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000033558 biomineral tissue development Effects 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000007596 consolidation process Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 230000008676 import Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 238000012966 insertion method Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
Classifications
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- 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
- E02D3/12—Consolidating by placing solidifying or pore-filling substances in the soil
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D15/00—Handling building or like materials for hydraulic engineering or foundations
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- Engineering & Computer Science (AREA)
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- Life Sciences & Earth Sciences (AREA)
- General Engineering & Computer Science (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- Agronomy & Crop Science (AREA)
- Environmental & Geological Engineering (AREA)
- Soil Sciences (AREA)
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
Abstract
The device comprises a slurry barrel, a grouting machine, a pressure gauge grouting valve and a slurry storage device which are sequentially connected through pipelines, wherein a slurry inlet is formed in the middle of the top surface of the slurry storage device, a slurry outlet is formed in the bottom surface of the slurry storage device, and a plurality of grouting openings are formed in the periphery of the slurry outlet in the bottom surface; the method for solidifying the loess foundation is used for carrying out reinforcement treatment on foundation soil with different collapse grades corresponding to different grouting methods; after grouting and reinforcing the foundation soil with strong collapsibility or medium collapsibility, backfilling the grouting holes by adopting a material ginger stone+ micp technology to form a novel green compaction material ginger stone pile body, curing for 1-2 weeks after the foundation treatment is finished, reducing or eliminating the foundation soil collapsibility in the treatment range after the foundation treatment, and improving the bearing performance of the foundation.
Description
Technical Field
The invention belongs to the technical field of environmental geotechnical engineering, and particularly relates to a device for solidifying a loess foundation by microorganism pressurized grouting and a method for solidifying the loess foundation.
Background
The cause of collapsible loess is mainly derived from its structure, salt solubility, under-pressure tightness, etc. Collapsible loess has higher intensity and lower compressibility under the state of natural lower moisture content, but when the soil body is soaked by water, the structural of soil body is destroyed, intensity is rapidly reduced, compressibility becomes great, and larger additional settlement can be generated under the same foundation load. Aiming at the disasters, the grouting technology is widely applied to soil reinforcement as one of key technologies in various foundation treatment and soil reinforcement. The mechanism is that slurry has compaction effect on soil body and forms a complex staggered 'net' slurry pulse structure to act on the soil body by skeleton effect, thus improving the integrity and bearing capacity of the soil body, and the microbial slurry is very friendly to environment and has very obvious protection effect on construction sites and surrounding environment. How to quickly reduce or eliminate the problem of collapsibility of the loess foundation and to improve the bearing performance of the loess foundation itself become a concern. Based on this, repeated grouting reinforcement is carried out on the loess foundation through the MICP pressurizing technology, so that the purposes of improving the loess strength and reducing or eliminating the loess collapsibility are achieved. In the existing MICP field reinforcement experiments, many researches are limited to grouting reinforcement of shallow foundations, namely, a grouting pipe insertion method is adopted, bacterial liquid and cementing liquid are respectively injected into soil, and after a period of time, the purpose of soil reinforcement is achieved. However, the effect of the technology after treatment shows obvious space difference, the calcium carbonate content and the mechanical strength of the soil body are obviously increased at the position close to the grouting opening, and the treatment effect is obviously weakened at the position far away from the grouting opening, so that the technology does not conform to the characteristics that the shallow foundation needs to be reinforced in a large range and the deep foundation needs to be locally reinforced in actual engineering diseases.
Patent application CN109959773B discloses a test device and a test method for grouting reinforced silt by using a demouldable microorganism, wherein the device consists of a GDS pressure controller, a slurry storage device, a reaction device and a filtrate collecting bottle 4. The pressure is provided by the GDS pressure controller, the grouting speed is precisely controlled, and the slurry is slowly and uniformly injected into the soil sample. The invention utilizes the microorganism mineralization technology to solidify the silt, adopts a method of injecting the bacterial liquid and the cementing liquid step by step, and well avoids the blockage of a grouting opening caused by direct mixing of the cementing liquid and the bacterial liquid. But respectively injecting bacterial liquid and cementing liquid into soil, the treated effect shows obvious space difference, the calcium carbonate content and mechanical strength of the soil are obviously increased at the position close to the grouting opening, and the treated effect is obviously weakened at the position far away from the grouting opening, so that the method does not conform to the characteristics of large reinforcing range of a shallow foundation and local reinforcing of a deep foundation in actual engineering diseases.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide a device for solidifying a loess foundation by microorganism pressurized grouting and a method for solidifying the loess foundation, which rely on MICP (microorganism-induced calcium carbonate precipitation) technology, and can be used for solidifying soil body by grouting to a certain depth by utilizing a slurry storage device under proper pressure for slightly collapsible loess foundation; for the loess foundation with medium collapsibility or strong collapsibility, a grouting pipe method can be adopted, a grouting pipe in the device is inserted into the soil body with holes, a pressurizing grouting machine is utilized to inject microorganism solution into the soil body, compaction and reinforcement are carried out on the soil body, so that slurry can be well and uniformly distributed in a soil sample, and the uniformity and the integrity of soil sample solidification are ensured; and the microorganism itself exists in natural environment, and the use of slurry in the construction process can not produce substances harmful to the environment, thus the effect of green construction can be achieved.
In order to achieve the above purpose, the present invention provides the following technical solutions:
The utility model provides a device of microorganism pressurization slip casting solidification loess foundation, includes thick liquid bucket 1, slip casting machine 2, manometer 3, slip casting valve 4 and thick liquid reservoir 5 that connect gradually through the pipeline, open in the middle of the thick liquid reservoir 5 top surface has thick liquid import 6, and the bottom surface is offered thick liquid export 7 relatively, still is offered a plurality of slip casting mouths 8 around the bottom surface thick liquid export 7.
The slurry barrel 1 comprises an A slurry barrel and a B slurry barrel which are arranged in parallel, respectively contain proportioned bacterial liquid and cementing liquid, and then pipelines are respectively connected in parallel to the grouting machine 2 for liquid mixing.
The slurry reservoir 5 has a cylindrical shape.
Grouting pipes 9 can be movably inserted into the slurry inlet 6 and the slurry outlet 7.
And a plurality of slurry dispersing ports 10 are also arranged around the pipe body at the lower end of the grouting pipe 9.
The length of the grouting pipe 9 is larger than the depth of the foundation to be reinforced.
A method for solidifying loess foundation by microorganism pressurized grouting specifically comprises the following steps:
firstly, performing surface leveling operation on the shallow surface of a loess area, and cleaning a site;
Step two, dividing loess foundation collapse grades according to the loess collapse amount: solving a collapse coefficient according to the pressure specified by engineering; the collapsible grade of collapsible loess is classified according to the size of a collapsible coefficient: strong collapsibility, moderate collapsibility and slight collapsibility;
And step three, when the collapse level of the loess field does not meet the construction requirement of the building foundation engineering, reinforcing the foundation according to the collapse level of the loess foundation measured in the step two: if the grouting is slightly collapsible, adopting a grouting reinforcement scheme, namely grouting treatment by using a slurry storage 5; if the collapse level is strong collapse or medium collapse, grouting is performed by pressurizing through a grouting pipe 9 in a grouting reinforcement mode; when a large-scale strong collapsible loess foundation needs to be treated, the slurry storage 5 and the grouting pipe 9 can be combined for on-site arrangement grouting;
Step four, a slurry barrel 1, a grouting machine 2, a pressure gauge 3, a grouting valve 4 and a slurry storage 5 which are sequentially connected through pipelines, wherein the slurry storage 5 is arranged on a loess foundation to be reinforced;
Step five, placing the proportioned bacterial liquid and cementing liquid in a slurry barrel A and a slurry barrel B respectively;
step six, opening a grouting valve 4, starting a grouting machine 2, and injecting the slurry into soil under the pressure of 0.1-0.5 MP;
Step seven, after grouting is completed aiming at the foundation problems with different collapse grades, backfilling the grouting holes with ginger stone powder and micp technology to form a compaction material Jiang Danfen pile body and tamping and compacting;
Step eight, backfilling the grouting holes, tamping the loess foundation, detecting and protecting the loess foundation, and curing for 1-2 weeks;
and step nine, finishing the reinforcement and collapsibility elimination of the loess foundation.
And the diameter of the seventh grouting hole is 70-110 mm.
Before the seventh tamping construction, a tamping test is performed to determine reasonable tamping quantity and tamping times, and the indexes to be achieved by the detection method are determined according to the tamping quality standard: the average compaction coefficient of soil among piles is not less than 0.92; the infiltration hole bottom must be tamped before filling; filling materials are backfilled and tamped in layers; the filler amount must not be less than the design value; the compaction coefficient of the pile body is not less than 0.96; the backfill grouting of the material ginger stone powder adopts continuous construction, and grouting is carried out after each pile hole is backfilled and tamped in a one-step layered manner, so that construction is not carried out at intervals or every other day so as not to reduce the bearing capacity of the pile.
The seventh step is to fill ginger stone powder into the infiltration holes and to tamp and compact the ginger stone powder in the following sequence: the process is carried out by 1-2 holes from outside to inside, and the thickness of the layered filler is not more than 35cm.
Compared with the prior art, the invention has the following beneficial effects:
1. The foundation adopts a microorganism pressurizing grouting consolidation process, and the foundation soil with different collapse grades corresponds to different grouting methods to be reinforced; after grouting and reinforcing the foundation soil with strong collapsibility or medium collapsibility, backfilling the grouting holes by adopting a material ginger stone powder+ micp technology to form a novel green compaction material ginger stone powder pile body, curing for 1-2 weeks after the foundation treatment is finished, reducing or eliminating the foundation soil collapsibility in a treatment range after the foundation treatment, and well uniformly distributing slurry in a soil sample to ensure the uniformity and the integrity of soil sample curing, so that the bearing performance of the foundation is improved.
2. The microbial solution is very friendly to the environment in the reinforcing process, and can be used for reinforcing the loess foundation in engineering under the premise of not damaging the environment, so that the purposes of reducing or eliminating collapsibility of loess with different collapsibility grades and improving the bearing performance of the loess foundation are realized under the premise of protecting construction and surrounding environment.
Drawings
Fig. 1 is a flowchart of a method for solidifying loess foundation by microorganism pressurized grouting according to the present invention.
Fig. 2 is a schematic structural view of the loess foundation reinforcing construction apparatus according to the present invention, wherein fig. 2 (a) is a perspective view thereof and fig. 2 (b) is a bottom view thereof.
Fig. 3 is a side view showing the arrangement of the apparatus of the present invention, in which (a) is a side view showing the construction arrangement of a shallow loess foundation under slurry storage tank and (b) is a side view showing the construction arrangement of a deep loess foundation under grouting pipe.
In the figure: 1. a slurry barrel; 2. a grouting machine; 3. a pressure gauge; 4. a grouting valve; 5. a slurry reservoir; 6. a slurry inlet; 7. a slurry outlet; 8. a grouting port; 9. grouting pipe; 10. slurry dispersion port.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings.
Referring to fig. 2 to 3, a device for solidifying loess foundation by microorganism pressurized grouting comprises a slurry barrel 1, a grouting machine 2, a pressure gauge 3, a grouting valve 4 and a slurry storage 5 which are sequentially connected through pipelines, wherein a slurry inlet 6 is formed in the middle of the top surface of the slurry storage 5, a slurry outlet 7 is formed in the bottom surface of the slurry storage 5, and a plurality of grouting openings 8 are formed around the slurry outlet 7 in the bottom surface.
The slurry barrels 1 are arranged in parallel, respectively contain the proportioned bacterial liquid and cementing liquid, and then the pipelines are respectively connected in parallel to the grouting machine 2 for liquid mixing.
The slurry reservoir 5 has a cylindrical shape.
The grouting opening 8 is movably inserted with a grouting pipe 9.
And a plurality of slurry dispersing ports 10 are also arranged around the pipe body at the lower end of the grouting pipe 9.
The length of the grouting pipe 9 is larger than the depth of the foundation to be reinforced.
Referring to fig. 1, a method for solidifying loess foundation by microorganism pressurized grouting specifically comprises the following steps:
Firstly, performing surface leveling operation on the shallow surface of a loess area, and cleaning a site; removing impurities and large soil;
Step two, dividing loess foundation collapse grades according to the loess collapse amount: determining the collapse coefficient according to the pressure specified by engineering (generally about 2X 10 5 Pa, and 20 tons/square meter); the collapsible grade of collapsible loess is classified according to the size of a collapsible coefficient: strong collapsibility, moderate collapsibility and slight collapsibility;
And step three, when the collapse level of the loess field does not meet the construction requirement of the building foundation engineering, reinforcing the foundation according to the collapse level of the loess foundation measured in the step two: if the grouting is slightly collapsible, adopting a grouting reinforcement scheme, namely grouting treatment by using a slurry storage 5; if the loess foundation collapse level is strong collapsible or medium collapsible, adopting a grouting reinforcement mode to perform pressurized grouting through the grouting pipe 9; when a large-scale strong collapsible loess foundation needs to be treated, the slurry storage 5 and the grouting pipe 9 can be combined for on-site arrangement grouting;
Step four, a slurry barrel 1, a grouting machine 2, a pressure gauge 3, a grouting valve 4 and a slurry storage 5 which are sequentially connected through pipelines, wherein the slurry storage 5 is arranged on a loess foundation to be reinforced;
Step five, placing the proportioned bacterial liquid and cementing liquid in a slurry barrel A and a slurry barrel B respectively;
step six, opening a grouting valve 4, starting a grouting machine 2, and injecting the slurry into soil under the pressure of 0.1-0.5 MP;
Step seven, after grouting is completed aiming at the foundation problems with different collapse grades, backfilling the grouting holes with ginger stone powder and micp technology to form a compaction material Jiang Danfen pile body and tamping and compacting;
Step eight, backfilling the grouting holes, tamping the loess foundation, detecting and protecting the loess foundation, and curing for 1-2 weeks;
and step nine, finishing the reinforcement and collapsibility elimination of the loess foundation.
In the third step, when the depth of the yellow soil foundation is not more than 5m, the grouting pipes 9 are not needed to be inserted into the slurry inlet 6 and the slurry outlet 7, when the depth of the yellow soil foundation is more than 5m, the grouting pipes 9 are inserted into the slurry inlet 6 and the slurry outlet 7, and when the large-scale yellow soil foundation needs to be treated, namely, the deep and shallow foundation soil needs to be reinforced, the slurry storage 5 and grouting pipe 9 combined device can be adopted for field arrangement grouting.
Before the seventh tamping construction, a tamping test is performed to determine reasonable tamping quantity and tamping times, and the indexes to be achieved by the detection method are determined according to the tamping quality standard: the average compaction coefficient of soil among piles is not less than 0.92; the infiltration hole bottom must be tamped before filling; filling materials are backfilled and tamped in layers; the filler amount must not be less than the design value; the compaction coefficient of the pile body is not less than 0.96; continuous construction is adopted for backfill grouting, grouting is carried out after each pile hole is backfilled and tamped in a layered mode, and construction is not carried out at intervals or every other day so as to avoid reduction of the bearing capacity of the pile.
The seventh step is to fill ginger stone powder into the infiltration holes and to tamp and compact the ginger stone powder in the following sequence: the process is carried out by 1-2 holes from outside to inside, the compaction is carried out by layering, and the thickness of the filling material is not more than 35cm.
And (5) curing for 1-2 weeks after the foundation treatment is finished.
Examples:
In the shallow foundation range, as shown in fig. 3 (a), the microorganism solution in the slurry storage 5 infiltrates into the loess foundation through the round hole on the lower surface of the slurry storage by means of proper pressure, so that grouting reinforcement soil with a certain depth can be achieved; when the depth of the treated foundation exceeds 5m underground, a grouting pipe method is adopted, as shown in fig. 3 (b), a grouting pipe 9 in the device is inserted into the soil body with holes, and a pressurizing grouting machine 2 is used for injecting microorganism solution into the soil body to perform compaction reinforcement on the soil body; when the loess foundation in a large range is required to be treated, namely, the deep foundation soil and the shallow foundation soil are required to be reinforced, the slurry storage device and the grouting pipe combined device can be used for field arrangement grouting, as shown in fig. 3 (c), and the two grouting devices are combined to be used for reinforcing the soil in a larger range. And carrying out grouting information statistics and settlement detection in the whole process strictly according to informationized construction, and sequentially evaluating and adjusting rationality of the designed construction parameters.
And (3) after the hole forming grouting is completed in the construction process, backfilling construction is carried out. The backfill construction technology adopts a material Jiang Danfen + micp technology, and the material Jiang Danfen is calcium nodule in a yellow soil layer or a weathered red soil layer. And (3) the construction sequence of pore forming and pore backfilling tamping is carried out from outside to inside at intervals of 1-2 pores. And (5) backfilling, tamping and compacting in layers. The thickness of the filler must not be greater than 35cm.
Before tamping, a tamping test should be performed to determine reasonable tamping quantity and tamping times, and the index to be reached by the detection method should be determined according to the tamping quality standard. The average compaction coefficient of soil between piles is not less than 0.92. The hole bottom must be tamped before filling. The filler is backfilled and tamped in layers. The filler amount must not be less than the design value. The compaction coefficient of the pile body is not less than 0.96. The backfill grouting of the material ginger stone powder adopts continuous construction, and grouting is carried out after each pile hole is backfilled and tamped in a one-step layered manner, so that construction is not carried out at intervals or every other day so as not to reduce the bearing capacity of the pile.
The grouting effect is usually checked after the grouting is finished for 28 days, and the checking method is as follows:
And calculating the grouting amount by statistics.
And the change of the soil body mechanical indexes before and after reinforcement is tested by using static sounding to know the reinforcement effect.
And (3) carrying out a water pumping test on site, and measuring the permeability coefficient of the reinforced soil body.
And (5) measuring the bearing capacity and the deformation modulus of the reinforced soil body by adopting a field static load test.
And measuring the dynamic elastic modulus and the shear modulus of the reinforced soil body by adopting a drilling elastic wave test.
The mechanical property of the reinforced soil body is measured by adopting a dynamic sounding method such as a standard penetration test or light sounding, and the like, and the method can directly obtain the strength of the in-situ soil before and after grouting for comparison.
Indoor experiments were performed. And judging the reinforcement effect through a comparison test of physical and mechanical indexes of soil before and after indoor reinforcement.
Among the above methods, the dynamic sounding test and the static sounding test are the most convenient and practical. The evaluation of the grouting effect should pay attention to the comparison of the data before and after grouting to comprehensively evaluate the grouting effect. The inspection points are generally 2% -5% of the number of grouting holes, for example, the reject ratio of the inspection points is equal to or more than 20%, or the average value of the inspection points is less than 20% but does not reach the design requirement, and repeated grouting is carried out on the reject grouting areas after the design principle is confirmed to be correct.
Claims (10)
1. A method for solidifying loess foundation by microorganism pressurized grouting is characterized in that: the method specifically comprises the following steps:
firstly, performing surface leveling operation on the shallow surface of a loess area, and cleaning a site;
Step two, dividing loess foundation collapse grades according to the loess collapse amount: solving a collapse coefficient according to the pressure specified by engineering; the collapsible grade of collapsible loess is classified according to the size of a collapsible coefficient: strong collapsibility, moderate collapsibility and slight collapsibility;
And step three, when the collapse level of the loess field does not meet the construction requirement of the building foundation engineering, reinforcing the foundation according to the collapse level of the loess foundation measured in the step two: if the grouting material is slightly collapsible, adopting a grouting reinforcement scheme, namely grouting by using a slurry storage (5); if the loess foundation collapse level is strong collapsible or medium collapsible, adopting a grouting reinforcement mode to perform pressurized grouting through a grouting pipe (9); when a large-scale strong collapsible loess foundation is required to be treated, the slurry storage (5) and the grouting pipe (9) can be combined for on-site arrangement grouting;
step four, a slurry barrel (1), a grouting machine (2), a pressure gauge (3), a grouting valve (4) and a slurry storage device (5) which are sequentially connected through pipelines, wherein the slurry storage device (5) is arranged on a loess foundation to be reinforced;
Step five, placing the proportioned bacterial liquid and cementing liquid in a slurry barrel A and a slurry barrel B respectively;
Step six, opening a grouting valve (4), starting a grouting machine (2) to enable slurry to be injected into soil under the pressure of 0.1-0.5 MP;
Step seven, after grouting is completed aiming at the foundation problems with different collapse grades, backfilling the grouting holes with ginger stone powder and micp technology to form a compaction material Jiang Danfen pile body and tamping and compacting;
Step eight, backfilling the grouting holes, tamping the loess foundation, detecting and protecting the loess foundation, and curing for 1-2 weeks;
and step nine, finishing the reinforcement and collapsibility elimination of the loess foundation.
2. The method for solidifying loess foundation by microbial pressurized grouting as claimed in claim 1, wherein: and the diameter of the seventh grouting hole is 70-110 mm.
3. The method for solidifying loess foundation by microbial pressurized grouting as claimed in claim 1, wherein: before the seventh tamping construction, a tamping test is performed to determine reasonable tamping quantity and tamping times, and the indexes to be achieved by the detection method are determined according to the tamping quality standard: the average compaction coefficient of soil among piles is not less than 0.92; the infiltration hole bottom must be tamped before filling; filling materials are backfilled and tamped in layers; the filler amount must not be less than the design value; the compaction coefficient of the pile body is not less than 0.96; the backfill grouting of the material ginger stone powder adopts continuous construction, and grouting is carried out after each pile hole is backfilled and tamped in a one-step layered manner, so that construction is not carried out at intervals or every other day so as not to reduce the bearing capacity of the pile.
4. The method for solidifying loess foundation by microbial pressurized grouting as claimed in claim 1, wherein: the seventh step is to fill ginger stone powder into the infiltration holes and to tamp and compact the ginger stone powder in the following sequence: the process is carried out by 1-2 holes from outside to inside, the compaction is carried out by layering, and the thickness of the filling material is not more than 35cm.
5. A method for solidifying loess foundation by microorganism pressure grouting as set forth in any one of claims 1 to 4, wherein: a device for above-mentioned microorganism pressurization slip casting solidification loess foundation includes, through thick liquid bucket (1), slip casting machine (2), manometer (3), slip casting valve (4) and thick liquid storer (5) that the pipeline connects gradually, its characterized in that: the middle of the top surface of the slurry storage device (5) is provided with a slurry inlet (6), the bottom surface is provided with a slurry outlet (7) relatively, and a plurality of grouting openings (8) are also formed around the slurry outlet (7) on the bottom surface.
6. The method for solidifying loess foundation by microbial pressure grouting as set forth in claim 5, wherein: the slurry barrel (1) comprises an A slurry barrel and a B slurry barrel which are arranged in parallel, respectively contain the proportioned bacterial liquid and cementing liquid, and then the pipelines are respectively connected in parallel to the grouting machine (2) for liquid mixing.
7. The method for solidifying loess foundation by microbial pressure grouting as set forth in claim 5, wherein: the slurry reservoir (5) is cylindrical.
8. The method for solidifying loess foundation by microbial pressure grouting as set forth in claim 5, wherein: grouting pipes (9) can be movably inserted into the slurry inlet (6) and the slurry outlet (7).
9. The method for solidifying loess foundation by microbial pressurized grouting as claimed in claim 8, wherein: the periphery of the pipe body at the lower end of the grouting pipe (9) is also provided with a plurality of slurry dispersing ports (10).
10. The method for solidifying loess foundation by microbial pressurized grouting as claimed in claim 8, wherein: the length of the grouting pipe (9) is larger than the depth of the foundation to be reinforced.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211349818.5A CN115450198B (en) | 2022-10-31 | 2022-10-31 | Device for solidifying loess foundation through microorganism pressurization grouting and method for solidifying loess foundation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211349818.5A CN115450198B (en) | 2022-10-31 | 2022-10-31 | Device for solidifying loess foundation through microorganism pressurization grouting and method for solidifying loess foundation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115450198A CN115450198A (en) | 2022-12-09 |
| CN115450198B true CN115450198B (en) | 2024-05-14 |
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR200238954Y1 (en) * | 2001-04-14 | 2001-10-11 | 원 회 양 | A block wrapping a ground surface for improvement of softground by grouting method. |
| KR20160014483A (en) * | 2014-07-29 | 2016-02-11 | 주식회사 지앤지테크놀러지 | Eco-friendly underground well grouting material and underground well grouting method using thereof |
| CN106285723A (en) * | 2016-08-30 | 2017-01-04 | 东南大学 | Microorganism grouting device and method after a kind of shield tunnel liner wall |
| CN107064472A (en) * | 2017-03-29 | 2017-08-18 | 河海大学 | The experimental rig and test method of a kind of microorganism grouting and reinforcing cylinder sand sample |
| CN112160313A (en) * | 2020-09-29 | 2021-01-01 | 西安工业大学 | Undisturbed Q4Loess or remolded Q4Loess reinforcing method |
| CN112813953A (en) * | 2020-12-29 | 2021-05-18 | 南京工业大学 | Device for reinforcing foundation by microorganism ultrasonic grouting and construction method thereof |
| CN215105065U (en) * | 2020-12-14 | 2021-12-10 | 天津大学 | Microbial improvement river course shore protection device |
| CN215728146U (en) * | 2021-09-14 | 2022-02-01 | 西安建筑科技大学 | Test device for microorganism pressurization grouting solidification loess |
-
2022
- 2022-10-31 CN CN202211349818.5A patent/CN115450198B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR200238954Y1 (en) * | 2001-04-14 | 2001-10-11 | 원 회 양 | A block wrapping a ground surface for improvement of softground by grouting method. |
| KR20160014483A (en) * | 2014-07-29 | 2016-02-11 | 주식회사 지앤지테크놀러지 | Eco-friendly underground well grouting material and underground well grouting method using thereof |
| CN106285723A (en) * | 2016-08-30 | 2017-01-04 | 东南大学 | Microorganism grouting device and method after a kind of shield tunnel liner wall |
| CN107064472A (en) * | 2017-03-29 | 2017-08-18 | 河海大学 | The experimental rig and test method of a kind of microorganism grouting and reinforcing cylinder sand sample |
| CN112160313A (en) * | 2020-09-29 | 2021-01-01 | 西安工业大学 | Undisturbed Q4Loess or remolded Q4Loess reinforcing method |
| CN215105065U (en) * | 2020-12-14 | 2021-12-10 | 天津大学 | Microbial improvement river course shore protection device |
| CN112813953A (en) * | 2020-12-29 | 2021-05-18 | 南京工业大学 | Device for reinforcing foundation by microorganism ultrasonic grouting and construction method thereof |
| CN215728146U (en) * | 2021-09-14 | 2022-02-01 | 西安建筑科技大学 | Test device for microorganism pressurization grouting solidification loess |
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