CN113931236A

CN113931236A - Construction process for shaping and seepage prevention of garbage mountain

Info

Publication number: CN113931236A
Application number: CN202111278848.7A
Authority: CN
Inventors: 王帅超; 乔新泉; 吴志勇; 赵保勇
Original assignee: China National Chemical Engineering No14 Construction Co ltd
Current assignee: China National Chemical Engineering No14 Construction Co ltd
Priority date: 2021-10-31
Filing date: 2021-10-31
Publication date: 2022-01-14

Abstract

An application of a construction process for mountain reshaping seepage prevention in garbage mountain seepage prevention and collapse prevention comprises the following steps: pouring the impervious wall and the concrete cover plate, and performing curtain grouting after the impervious wall and the concrete cover plate reach certain strength; performing curtain grouting after the consolidation grouting is finished and the inspection and acceptance are qualified; the curtain grouting process comprises the following steps: cleaning a covering layer → lofting hole → embedding a grouting pipe → pouring a concrete cover plate → grouting and drilling a curtain → washing hole wall → blocking hole opening → washing crack → pressurized water experiment → grouting → sealing hole → quality inspection; the auxiliary cast-in-place concrete cover plate is arranged, grouting conditions can be improved, the grouting effect is improved, the qualification rate of hole positions, hole depths and hole inclination of drilled holes reaches more than 99.5%, the production efficiency is improved, and the construction quality is effectively improved; the hole wall flushing and the crack flushing are carried out in a high-flow pressure water pulsation mode, double-row hole grouting is adopted, the construction efficiency is greatly improved, the actual construction period is shortened by 12 days, the labor cost is saved by 36 ten thousand yuan, and the direct economic benefit is obvious.

Description

Construction process for shaping and seepage prevention of garbage mountain

Technical Field

The invention belongs to the technical field of large garbage mountain closure and environmental protection, and particularly relates to a mountain reshaping seepage-proofing construction process and application thereof in seepage-proofing and collapse-proofing of a garbage mountain.

Background

At present, environmental protection receives people's more and more attention, and urban garbage pollution has become the restriction factor of city rapid development, especially the peripheral landfill of city, and a lot of all are overload operation, and some have reached design service life, if do not take the measure to handle, will bring a series of environmental pollution problems, for example: the infiltration of waste liquid, collapse of garbage mountain, landslide, etc., especially the pollution to underground water, which is difficult to be treated later.

Disclosure of Invention

In order to solve the problems, the invention provides a garbage mountain shaping and seepage-proofing construction process for sealing a garbage field and preventing waste liquid from leaking and application thereof.

In order to achieve the purpose, the invention provides the following technical scheme:

the invention provides a construction process for shaping and seepage prevention of a mountain.

The invention also provides application of the construction process for mountain reshaping seepage prevention in the seepage prevention and collapse prevention of the garbage mountain.

The construction process comprises the following steps:

(1) constructing a concrete cover plate, cleaning the upper surface of a mountain body, lofting hole positions, embedding a grouting pipe, and pouring the concrete cover plate;

(2) constructing a pilot hole, wherein the grouting hole comprises a first-order hole, a second-order hole and a third-order hole, the pilot hole is selected from the first-order hole, the pilot hole adopts a seamless steel pipe to protect the wall, and the depth of the steel pipe reaches a completely weathered rock stratum;

(3) drilling a curtain grouting hole, adopting a phi 135mm rotary drilling machine or a punching drilling machine to drill, and after indicating to embed a hole pipe according to the technical requirements of design drawings, drilling by using a small-caliber phi 90mm diamond bit down-the-hole drilling machine until a final hole is formed; core samples are drilled in the grouting pilot holes and the inspection holes, the core samples are not drilled in the common grouting holes, and the core obtaining rate is not less than 80%.

(4) Drilling hole flushing, wherein hole wall flushing and fracture flushing are carried out in a high-flow pressure water pulsation mode until backwater is clarified and lasts for 10min, the deposition thickness of the hole bottom is not more than 20cm, and the flushing water pressure is 80% of the grouting pressure; when the pressure of the flushing water is more than 1Mpa, 1Mpa is adopted;

(5) performing a pressurized water test, namely performing the pressurized water test on the curtain grouting pilot hole, the curtain grouting hole and the inspection hole; carrying out a water pressing test on the curtain grouting pilot hole and the inspection hole in a segmented manner from top to bottom, wherein the test adopts a single-point method or a five-point method, and the grouting hole is used for carrying out a simple water pressing test;

(6) curtain grouting, namely performing circulating grouting, adopting double-row hole grouting and performing sequential encryption according to the principle of sequential encryption, namely filling first-sequence holes, then filling second-sequence holes and finally filling third-sequence holes; wherein, the first-order hole grouting adopts the filling mode construction of top-down, closed orifice and hole internal circulation, the second-order and third-order hole grouting adopts the filling mode construction from bottom to top, and when the bottom to top filling mode is adopted, each grouting hole can be subjected to one-time crack flushing before grouting;

(7) and after grouting is finished, sealing the grouting holes after acceptance inspection is qualified, and performing quality inspection 28 days after grouting is finished, wherein the number of inspection holes is 10 percent of the total number.

Furthermore, the height of the mountain body is 8-30 meters, and the mountain body is loose in covering and cannot be used for excavating the construction geology.

Furthermore, the thickness of the concrete cover plate in the step (1) is more than or equal to 500mm, the width of the concrete cover plate is more than or equal to 4.0m, and the concrete cover plate is formed by pouring concrete with a C25 standard.

Further, the outer diameter of the steel pipe in the step (2) is 133mm, and the wall thickness is 4 mm; the spacing of the pilot holes is more than or equal to 15m or is arranged according to 10% of the number of the holes.

Further, the aperture of the grouting hole in the step (3) is 90mm, and the pitch is 1.5 m.

Further, in the step (6), the curtain grouting is performed in sections, wherein the length of the first section is 2-3 meters, the length of the hole cutting pipe, the length of the second section, the length of the third section and the length of the fourth section are 5 meters, and each section is 2 meters later until the water permeability q of the final hole section of two continuous sections of grouting holes is less than or equal to 1 Lu; when the circulating grouting is used, the distance between the grout injection pipe and the bottom of the hole is not more than 50 cm.

Further, in the step (5), the depth of the inspection hole is 2m less than that of the grouting hole.

Further, in the step (6), the grout is a mixture of cement and water or a mixture of cement, water and sand; the fineness of the cement requires that the allowance of the cement passing through an 80-micron square-hole sieve is not more than 5 percent; sieving the grouted slurry before use, wherein the time from preparation to use of the slurry is less than 4h, and the temperature of the slurry is 5-40 ℃; the flow speed of the slurry during grouting is 1.4-2.0 m/s.

Further, when the grout of the grouting is a mixture of cement and water, the water-cement ratio is six ratio levels of 5:1, 3:1, 2:1, 1:1, 0.8:1, 0.6:1 or 0.5: 1; when the grout is a mixture of cement, water and sand, the ratio of water: cement: sand is 1: 1:1 or 1: 1: 0.6.

further, in step (7), the grouting end criterion is: grouting from top to bottom in a segmented mode, under the design pressure, when the injection rate is not more than 1L/min, continuously grouting for 60min, and then grouting is finished; and (3) when the bottom-up grouting is adopted, under the design pressure, when the injection rate is not more than 1L/min, the grouting is continued for 30min, and the grouting can be finished.

The deviation of the hole position of the opening and the design position is not more than 100mm, and the deviation of the hole bottom is not more than 300 mm; and (4) during drilling, carrying out full-hole inclination measurement, correcting in time, and re-drilling when the deviation exceeds a specified value. Other grout holes and inspection holes should have a hole bottom deviation less than 1/40 holes deep. The final hole depth of the drilled hole should be in accordance with design specifications. Records should be made for the actual depth, hole position and hole inclination of each drilling hole.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the mountain reshaping seepage-proofing construction process is applied to garbage sealing to prevent waste liquid from leaking, solves the problems of soft soil, incompact soil and high excavation risk of garbage mountains in the garbage mountain sealing in the prior art, and achieves the aim of effectively preventing waste liquid from seeping.

The auxiliary cast-in-place concrete cover plate is arranged, grouting conditions can be improved, grouting effect is improved, the qualification rate of hole positions, hole depths and hole inclination of drilled holes reaches more than 99.5%, production efficiency is improved, and construction quality can be effectively improved.

The curtain grouting holes are subjected to hole wall flushing and crack flushing in a high-flow pressure water pulsation mode, double-row hole grouting is adopted, the construction efficiency is greatly improved, the construction period is actually shortened by 12 days, labor cost is saved by 36 ten thousand yuan, and direct economic benefits are obvious.

The invention has the advantages of advanced technical process, safe and reliable operation environment, high construction efficiency, strict process quality control and compact connection among all working procedures, creates good achievement for environmental protection, obviously improves social benefit and economic benefit, has strong operability and has good popularization value.

Drawings

FIG. 1 is a construction flow chart of garbage mountain body shaping seepage prevention according to the embodiment of the invention.

Detailed Description

The technical solutions provided by the present invention will be described in detail below with reference to specific examples, and it should be understood that the following specific embodiments are only illustrative of the present invention and are not intended to limit the scope of the present invention.

Examples

The field sealing project of the landfill site of the south mountain refuse treatment plant in Jinzhou city is a relatively large-scale landfill site sealing project at present in China, the volume of the garbage is about 80 ten thousand square, and the field sealing coverage area reaches 23 ten thousand square.

And a YJL-100 type down-the-hole drill, an XU-300 type rotary drilling machine and an impact drilling machine are selected to finish the drilling operation of all grouting holes and inspection holes, a high-speed stirrer and a slurry pump are arranged at a slurry making station according to the requirement for slurry conveying, and main grouting equipment such as a sufficient slurry filling pump, a double-layer stirrer, an automatic recorder and the like are arranged at each grouting point according to the requirement.

The pulping station is provided with 2 NJ-600 type high-speed mixers for pulping, 2 JJS-2A vertical double-layer common mixers for storing the pulp, 2 BW-200/40 type slurry pumps and a water supply and slurry delivery pipeline system. The scale of the pulping station is 500L/min. The slurry is delivered to each grouting point through a phi 200 slurry delivery main pipe and phi 25-phi 50 branch pipes. The centralized slurry-making station prepares pure water slurry liquid with a water-cement ratio of 0.5:1, the flow rate of the conveyed slurry liquid is 1.4-2.0 m/s, the density of the slurry is measured at each grouting point, and the slurry is prepared and used according to different requirements of each grouting point.

And arranging a vertical anti-seepage system around the mountain, and performing anti-seepage treatment in a mode of combining cement bentonite wall grouting with vertical curtain grouting in all areas of rock and soil. Preventing leachate from entering groundwater; the ground water and surface water outside the field are prevented from entering the refuse landfill body, so that the production amount of percolate is reduced; the landfill gas collection is facilitated. The thickness of the cement bentonite wall is 800 mm, the cement bentonite wall enters fully weathered rocks at the bottom, the curtain grouting impervious layer is not less than 2m, and the maximum depth of the impervious wall is about 15 m. The vertical curtain grouting is designed to be double-row holes, and the row spacing and the hole spacing are preliminarily determined to be 1.5 m. During construction, the downstream row is constructed first, and then the upstream row is constructed. The curtain grouting pressure is 0.5 to 1 MPa. The hole depth of the curtain grouting at least enters the weathered gneiss, the hole depth requires that the water permeability q of the final hole section is less than or equal to 1 Lurong, and the average hole depth is about 40 m.

Sequence of construction

The grouting construction sequence is as follows: pouring the impervious wall and the concrete cover plate, and performing curtain grouting after the impervious wall and the concrete cover plate reach certain strength; and performing curtain grouting after the consolidation grouting is finished and the check and acceptance are qualified.

Curtain grouting: cleaning a covering layer → lofting a hole site → embedding a grouting pipe → pouring a concrete cover plate → grouting a curtain and drilling a hole → washing the hole wall → blocking the hole site → washing a crack → a water pressing experiment → grouting → sealing → quality inspection.

The method comprises the following specific steps:

construction of concrete cover plate

Because the field is mostly filled with miscellaneous earth, the cracks can not be washed, the grouting pressure is limited, and the grouting effect is limited, a concrete cover plate needs to be arranged at the upper part so as to improve the grouting condition and the grouting effect, and the leakage on the surface layer can be effectively cut off, thereby reducing the damage caused by contact scouring.

Through on-site geological survey, the engineering is provided with a concrete cover plate. According to the design requirement, the concrete cover plate is in the form that: the thickness is 500mm, the width is 4.0m, and the pouring subsection access is reasonably formulated according to the field progress and the foundation clearing condition.

(1) The concrete cover plate construction process comprises the following steps:

grouting axis lofting → covering layer excavation → artificial foundation clearing → rock face acceptance → hole site lofting → embedded grouting pipe → concrete pouring.

(2) The technical requirements are as follows:

the cover plate is excavated by 1.5m³And (4) carrying out back-shovel excavation, manually repairing the groove, strictly preventing overexcavation, and tamping and encrypting the loose part. Hole site lofting needs to be strictly controlled, and the number of buried holes is properly increased for the over-loose parts according to the specification.

The concrete is poured by C25 concrete according to the design requirement, and commercial concrete is adopted.

(3) Pouring concrete

1) Before opening the bin and pouring, checking the in-place conditions of various plans of organizations before opening the bin, wherein the items comprise working procedure arrangement, personnel, materials, machines and tools, standby equipment and the like, and whether the plans are in place or not. Then, the commander arranges corresponding personnel and division of labor according to the actual situation of the warehouse surface.

2) Before opening the warehouse, a constructor carries out site technical intersection on a pouring team leader, and the contents are as follows: pouring position and height, opening time, concrete label, pouring sequence and mode, warehousing strength and corresponding equipment configuration, warehouse-in surface treatment and the like.

3) Before the concrete is put into the warehouse, machines, facilities, tools and materials which are cut into the warehouse are washed clean by pouring teams. And any warehousing facilities and personnel are not allowed to bring sundries into the warehouse, so that the concrete pouring quality is influenced.

4) In the pouring process, special (concurrent) staff in all aspects must seriously adhere to the post:

a. concrete carrying personnel need to carry concrete materials from a mixing plant to a pouring bin in time and often check the quality of the concrete materials, and if the concrete materials are abnormal, the concrete carrying personnel rapidly report to be on duty and process the concrete materials by quality inspection personnel.

b. For the quality condition of the concrete material entering the warehouse, the carrying personnel should feed back information at any time, which is beneficial to timely identifying and adjusting, and is beneficial to the quality and improvement of the concrete.

c. The vibrating personnel should immediately carry out vibrating work after the bin is leveled; the vibrating rod should be inserted quickly and pulled out slowly.

5) During the casting process, the following process is performed when the following problems are encountered:

a. when the concrete material is not supplied or the transportation equipment is in failure, the time is too long, the initial setting of the pouring surface is caused, and the pouring is difficult to recover, the report is timely reported to the quality safety department, the quality inspection personnel timely report the supervision engineer and process the concrete according to the instruction of the supervision engineer.

b. When heavy rain and heavy rain occur in the pouring process, the whole bin is covered by rain-proof cloth in time, and the concrete which is put into the bin is vibrated completely so as to avoid digging the bin after rain.

Grouting drill hole

The curtain grouting is carried out according to the principle of sequential encryption, and the first-sequence holes, the second-sequence holes and the third-sequence holes are poured firstly, then, the second-sequence holes and finally, the third-sequence holes are poured. The upper part of the field is filled with miscellaneous earth, the pilot holes are all made of seamless steel pipes for protecting walls, the depth of the steel pipes reaches to a completely weathered rock stratum, the outer diameter of the steel pipes is 133mm, and the wall thickness is 4 mm; the steel pipe is driven in and pulled out by adopting a pile driver.

(1) Pitch of holes

The curtain grouting is double-row, and the hole pitch of grouting holes is 1.5 m. The curtain grouting should arrange pilot holes first, the pilot holes are selected in a series of holes, its interval should not be less than 15 meters, or arrange according to 10% of the total hole number.

(2) Depth of hole

The depth of the curtain grouting hole is required to reach the position of the water permeability rate of the rock stratum of 1Lu, and the depth of the inspection hole is 2m less than that of the grouting hole at the position of the inspection hole.

(3) Pore diameter

The aperture of the curtain grouting pilot hole is 133mm, and the aperture of the grouting hole is 90 mm.

(4) Accuracy of drilling

Core drilling and core sample testing

(1) The core sample should be drilled in the grouting pilot hole and the inspection hole, and the core sample should not be drilled in the ordinary grouting hole. The core obtaining rate is not less than 80%.

(2) And testing the drilled rock core and the concrete core sample, and reporting and managing test records and results as acceptance documents.

(3) And performing system management and effective storage on the drilled core sample, and uniformly handing over a management unit after the engineering is completed.

Borehole flushing

The curtain grouting is carried out by adopting a rotary drilling machine and a diamond bit down-the-hole drilling machine. Firstly, drilling by using a phi 135mm rotary drilling machine or a punching drilling machine, and after embedding a hole pipe according to technical requirements or instructions of a supervision engineer, drilling by using a small-caliber phi 90mm diamond bit down-the-hole drilling machine until a final hole is formed;

after the hole is drilled to the designed depth, the hole depth and the hole bottom residues are checked, and the residues which do not meet the requirements are processed in time. And (3) performing hole wall flushing and crack flushing on the qualified drill holes in a high-flow pressure water pulsation mode until backwater is clarified and lasts for 10min, wherein the flushing water pressure is 80% of the grouting pressure, and when the reading value is more than 1MPa, 1MPa is adopted.

When the bottom-up grouting method is adopted, each grouting hole can be subjected to one-time crack flushing before grouting.

Grouting operation should be continuously performed immediately after the grouting hole is flushed, and interruption exceeds 24 hours for reasons. The grouting washing should be performed again before grouting.

Water pressure test

The pressurized water test is used for checking rock conditions, determining grouting parameters and detecting grouting quality. The grouting pilot hole and the inspection hole are required to be subjected to normal water pressure tests one by one, and the ordinary grouting hole is required to be subjected to simple water pressure tests.

The pressurized water test results calculate the q value according to the following formula:

q=Q/P.L；

in the formula, q is water permeability and the unit is Lu;

q is the pressing flow rate and the unit is L/min;

p is the total pressure acting in the test section, and the unit is MPa;

l is the length of the segment in m.

(1) And (3) a normal pressurized water test, namely adjusting the pressure to a specified value, measuring the injection rate for at least 4 times after the injection rate is kept stable, measuring and reading the pressed flow rate every 10min, finishing the pressurized water test when the test result meets one of the following standards, and taking the final flow rate reading as the calculated flow rate.

When the flow rate is more than 5L/min, the difference between the maximum value and the minimum value is less than 10 percent of the final value after four continuous readings.

And when the flow is less than 5L/min, the difference between the maximum value and the minimum value is less than 15 percent.

And thirdly, continuously reading for four times, wherein the flow is less than 0.5L/min.

(2) And (3) performing a simple pressurized water test for 30min before grouting in each grouting section of the common grouting hole, reading the pressing flow once every 5min, measuring for six times, and calculating the Lu value by using the last reading.

(3) Test pressure

When the grouting pressure is more than 1Mpa, the pressure of the pressurized water test is 1 Mpa.

(4) Record of the experiment

The necessary data of each water pressing test comprises hole numbers, section lengths, elevations of pressure gauges, elevations of underground water levels, water pressing pressure, flow, water pressing time, unit water absorption capacity, test date and the like.

Grouting agent

(1) Grouting material

Cement: P.O 42.5.5 ordinary portland cement is adopted, and the fineness of the ordinary portland cement is required to be not more than 5% of the ordinary portland cement passing through an 80um square-hole sieve.

Water: the water for on-site grouting is directly used by pumping clean river water to the construction part.

(2) Pulping

Weighing of pulp material

The pulping material must be weighed, and the weighing error should be less than 5%. The solid phase materials such as cement should be weighed by weight.

② stirring the slurry

Each slurry must be stirred uniformly and the density of the slurry measured and recorded.

Stirring time of pure cement slurry: when using a common stirrer, the time is not less than 3min, and when using a high-speed stirrer, the time is not less than 30 s. The slurry is sieved before use, and the time from the beginning of preparation to the end of use is less than 4 hours, and the slurry is regarded as waste slurry after more than 4 hours.

Thirdly, centralized pulping

The concentrated slurry-making station prepares pure cement slurry liquid with water-cement ratio of 0.5:1, and the slurry density of each grouting site is determined according to the requirements and is prepared and used according to different requirements of each grouting site.

The temperature of the slurry is kept between 5 and 40 ℃, and the slurry which is lower than or exceeds the standard is regarded as waste slurry.

Fourthly, conveying the slurry

During slurry conveying, the smoothness of the slurry conveying pipeline is ensured, and the deposition of the cement slurry in the pipe is avoided. The slurry conveying pressure is not too high, the slurry conveying pipeline is as flat and smooth as possible, the turning radius cannot be too small, and the overflowing section cannot generate sudden change. The flow rate of the slurry is 1.4-2.0 m/s.

(3) Grouting method

The curtain grouting is carried out according to the principle of encryption in sequence and segmental grouting. Firstly constructing I-order holes, then constructing II-order holes and finally constructing III-order holes. The first-order hole grouting adopts a top-down, orifice-closed and hole-internal-circulation grouting mode for construction, and the second-order and third-order hole grouting adopts a bottom-up grouting mode for construction.

(4) Grouting pressure

The curtain grouting pressure varies depending on the nature of the bedrock and the grouting hole site, and thus, the grouting pressure must be determined at the time of the grouting test. When grouting, the grouting pressure should reach the specified limit value as soon as possible, and the contact section and the hole section with large injection rate are subjected to sectional pressure rise; in the grouting process, the pressure is not allowed to be reduced, and continuous grouting under a specified constant pressure must be ensured.

(5) Standard of slurry water concentration

The water-cement ratio of the slurry is executed according to the parameters determined by the grouting test, and the slurry is gradually changed from thin to thick. The water-ash ratio of the slurry can adopt six stages of 5:1, 3:1, 2:1, 1:1, 0.8:1, 0.6:1 or 0.5:1, and the water-ash ratio of the initial irrigation water can adopt 5:1 stages. The grouting criteria is that the water-cement ratio must not be changed when the grouting pressure is kept constant, the injection rate continues to decrease, or when the injection rate is kept constant and the grouting pressure continues to increase.

Secondly, when the injection amount of a certain grade of grout reaches more than 300L, or the grouting time reaches 1h, and the grouting pressure and the injection rate are not obviously changed, the thick grade-one water-cement ratio grout is replaced for grouting, and when the injection rate is more than 30L/min, the grout can be thickened in a grade-exceeding manner according to the specific construction conditions.

Thirdly, in the grouting process, when the grouting pressure or the injection rate is suddenly changed greatly, the reason should be immediately found out, and corresponding measures are taken for treatment.

Fourthly, cement mortar can be poured when necessary, and the mixing proportion of the cement mortar is water: cement: sand is 1: 1:1 or 0.6: 1:1 two ratio grade slurry.

Measuring and recording the specific gravity of the grout at regular time and measuring and recording the temperature of the grout when necessary in the grouting process.

Sixthly, the grouting pressure gauge is arranged on the slurry return pipe and is provided with an oil slurry isolation device, and the average value of the swinging of the pointer is used as the standard for controlling the pressure during grouting.

(6) Special case handling

1) When the water permeability of the final hole section of the curtain grouting hole is larger than the design specification, whether the drilling hole is continuously deepened is determined after seeking design, supervision and owner opinions.

2) During grouting, slurry leakage and caulking, surface plugging, low pressure, thick slurry, flow limiting, quantity limiting and intermittent treatment are adopted according to specific conditions.

3) When slurry mixing occurs in the grouting process, if slurry mixing holes have grouting conditions, grouting can be carried out simultaneously, one pump is used for grouting one hole, otherwise, the slurry mixing holes are plugged, after grouting of the grouting holes is finished, the slurry mixing holes are flushed again, and drilling and grouting are continued.

4) And (3) in the grouting process, if the slurry is thickened after slurry return, replacing with new slurry with the same water-cement ratio for grouting, and if the effect is not obvious, stopping grouting after 30min of continuous grouting.

5) The grouting work must be continuously carried out, and if it is interrupted for this reason, it can be treated according to the following principle:

grouting should be restored as early as possible, otherwise, drilling should be flushed immediately, and then grouting should be restored. If the flushing cannot be carried out or is ineffective, hole sweeping is carried out, and then grouting is recovered.

And secondly, when grouting is recovered, grouting by using cement paste of an opening grouting ratio level. If the injection rate is similar to that before interruption, the cement paste of the specific grade before interruption can be used for continuous injection; if the injection rate is reduced more than before interruption, the slurry should be gradually enriched to continue the injection.

Thirdly, after grouting is resumed, if the injection rate is reduced greatly compared with that before interruption, and the slurry suction is stopped in a short time, remedial measures should be taken.

6) The drill way has the grout hole section of gushing water, should survey before the grout and note gush water pressure and gush the water yield, can choose following measures to handle according to gushing the water condition:

segmented grouting from top to bottom, short segment length, high grouting pressure, thick slurry ending, slurry screening, slurry closing, pure pressure type grouting, accelerator doping, waiting coagulation and pressure grouting hole sealing.

7) The injection amount of the grouting section is large, and when grouting is difficult to finish, the following measures can be selected for treatment:

low pressure, thick slurry, flow limiting, limited quantity, intermittent grouting; adding an accelerator into the slurry; pouring stable slurry or mixed slurry. And (5) cleaning the hole after the section is treated, and grouting according to the technical requirements again until the section is finished.

Standard of grouting end

Grouting from top to bottom in a segmented mode, under the design pressure, when the injection rate is not more than 1L/min, and continuously grouting for 60min, and then grouting can be finished; and (3) when the bottom-up grouting is adopted, under the design pressure, when the injection rate is not more than 1L/min, the grouting is continued for 30min, and the grouting can be finished.

Hole sealing

After the whole-hole grouting is finished, the inspection and acceptance can be carried out in time with an supervision engineer, and the grouting holes qualified in inspection and acceptance can be sealed.

Quality inspection

The curtain grouting quality inspection is mainly to inspect the permeability, compactness and continuity of the curtain body 28 days after grouting is finished at the position, and the number of inspection holes is 10 percent of the total number.

(1) Curtain grouting inspection hole arrangement principle:

firstly, rock breaking, fault, macropore and other parts with complex geological conditions;

near the hole section with large injection amount;

the part which is abnormal in grouting condition and is considered to have influence on the curtain quality through data analysis.

(2) The curtain grouting quality inspection is mainly based on the water pressure test result of an inspection hole and combines the analysis of completion data and the test result.

(3) And (3) inspection hole construction:

drilling a hole with the diameter of 46mm, boxing the core sample and filling the core sample with the number. The extraction rate is not less than 85 percent.

And secondly, the hole pressurized water is detected by adopting a single-point method, and the pressurized water is stable and standard: under stable pressure, the pressing flow is measured and read every 5min, and when the difference between the maximum value and the minimum value in the four continuous readings is less than 10% of the final value or the difference between the maximum value and the minimum value is less than 1L/min, the test at the stage can be finished, and the final value is taken as a calculated value.

(4) Curtain grouting quality evaluation standard: the percent of pass of the contact section of the concrete and the bedrock is 100 percent, and the percent of pass of other parts is not lower than 90 percent.

The technical means disclosed in the invention scheme are not limited to the technical means disclosed in the above embodiments, but also include the technical scheme formed by any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and such improvements and modifications are also considered to be within the scope of the present invention.

Claims

1. A construction process for shaping and seepage prevention of garbage mountains is characterized by comprising the following steps:

(3) drilling a curtain grouting hole, adopting a phi 135mm rotary drilling machine or a punching drilling machine to drill, burying a hole opening pipe according to the technical requirement, and then drilling by using a small-caliber phi 90mm diamond bit down-the-hole drilling machine until a final hole is formed;

(4) hole wall washing and crack washing are carried out in a high-flow pressure water pulsation mode until backwater is clarified and lasts for 10min, and the thickness of deposit at the bottom of a hole is not more than 20 cm;

2. The construction process for shaping and seepage-proofing the garbage mountain body according to claim 1, wherein the height of the mountain body is 8-30 m, and the mountain body is loose in covering and cannot be excavated into a construction geology.

3. The construction process for shaping and seepage-proofing the garbage mountain according to claim 1, wherein the thickness of the concrete cover plate in the step (1) is more than or equal to 500mm, the width of the concrete cover plate is more than or equal to 4.0m, and the concrete cover plate is cast by adopting C25-grade concrete.

4. The garbage mountain body shaping and seepage-proofing construction process according to claim 1, wherein in the step (2), the outer diameter of the steel pipe is 133mm, and the wall thickness is 4 mm; the spacing of the pilot holes is more than or equal to 15m or is arranged according to 10% of the number of the holes.

5. The construction process for shaping and seepage-proofing the garbage mountain according to claim 1, wherein the diameter of the grouting hole in the step (3) is 90mm, and the hole pitch is 1.5 m.

6. The garbage mountain reshaping seepage-proofing construction process according to claim 1, wherein in the step (6), curtain grouting is performed in sections, the length of the first section is 2-3 meters, the length of the hole cutting pipe is 5 meters, the length of the second section, the length of the third section and the length of the fourth section are all 5 meters, and then each section is 2 meters until the water permeability q of the final hole section of each two continuous sections of grouting holes is less than or equal to 1 Lu; when the circulating grouting is used, the distance between the grout injection pipe and the bottom of the hole is not more than 50 cm.

7. The construction process for reshaping and seepage control of garbage mountains as claimed in claim 1, wherein in the step (5), the depth of the inspection hole is 2m less than the depth of the grouting hole.

8. The construction process for reshaping and seepage-proofing a garbage mountain according to claim 1, wherein in the step (6), the grouting slurry is a mixture of cement and water or a mixture of cement, water and sand; the fineness of the cement requires that the allowance of the cement passing through an 80-micron square-hole sieve is not more than 5 percent; sieving the grouted slurry before use, wherein the time from preparation to use of the slurry is less than 4h, and the temperature of the slurry is 5-40 ℃; the flow speed of the slurry during grouting is 1.4-2.0 m/s.

9. The construction process for shaping and seepage-proofing the garbage mountain according to claim 8, wherein when the grout is a mixture of cement and water, the water-cement ratio is in six ratio levels of 5:1, 3:1, 2:1, 1:1, 0.8:1, 0.6:1 or 0.5: 1; when the grout is a mixture of cement, water and sand, the ratio of water: cement: sand is 1: 1:1 or 1: 1: 0.6.

10. the construction process for shaping and seepage-proofing garbage mountain bodies according to claim 1, wherein in the step (7), the grouting finishing standard is as follows: grouting from top to bottom in a segmented mode, under the design pressure, when the injection rate is not more than 1L/min, continuously grouting for 60min, and then grouting is finished; and (3) when the bottom-up grouting is adopted, under the design pressure, when the injection rate is not more than 1L/min, the grouting is continued for 30min, and the grouting can be finished.