阅读说明：本技术 沥青站回收粉在盾构施工中的应用 (Application of asphalt station recycled powder in shield construction ) 是由 孙晓辉 张胜安 周平 孙杰 乔秀兵 季斌 孙康 李洁 郭振 杨琳 王冠鹏 张鹏 于 2020-07-23 设计创作，主要内容包括：本发明提供了沥青站回收粉在盾构施工中的应用方法,将沥青站回收粉作为适用于盾构施工工况使用的施工原料之一,应用于土仓加泥、治理喷涌、盾构机带压开仓的泥膜形成、填充盾构机壳体与土之间的间隙、盾构机停机时的土压保持、同步注浆等工况,成本低,效果好,适宜于推广应用,以使沥青站回收粉在盾构施工领域能够得到有效的回收利用。(The invention provides an application method of asphalt station recovery powder in shield construction, which takes the asphalt station recovery powder as one of construction raw materials suitable for shield construction working conditions, is applied to working conditions of soil bin mud adding, gushing treatment, mud film formation of shield machine under pressure bin opening, filling of a gap between a shield machine shell and soil, soil pressure maintenance during shield machine halt, synchronous grouting and the like, has low cost and good effect, and is suitable for popularization and application, so that the asphalt station recovery powder can be effectively recycled in the field of shield construction.)

1. The application of the asphalt station recycling powder in shield construction is characterized in that: the slurry is used for treating gushing, and is prepared by mixing and stirring the following ingredients in percentage by mass: the ratio of the recovered powder to the water is 1: 1-1: 1.5, and the addition amount of the polyacrylamide is 0.3-0.5% of the mass of the recovered powder.

2. The use of the asphalt plant reclaimed powder of claim 1 in shield construction, wherein: recovery powder to water = 1: 1.2.

3. The use of the asphalt plant reclaimed powder of claim 1 or 2 in shield construction, characterized in that: the method comprises the following construction steps:

a1: proportioning, namely placing the proportioned material in a bentonite tank of a shield machine and stirring to form slurry;

a2: when the shield construction process encounters a gushing stratum, injecting the slurry obtained in the step A2 into a soil bin by using a bentonite injection system of the shield machine;

a3: under the action of the slurry, the mud and the stones in the soil bin are gathered into a cluster and are deposited at the bottom of the soil bin;

a4: and D, conveying the mud and stone conglomerate obtained in the step A3 to a conveying belt through a screw conveyor, and forming a soil plug inside the screw conveyor so as to block the gushing.

4. The use of the asphalt plant reclaimed powder of claim 3 in shield construction, wherein: in the step A1, the stirring speed is 80-120 r/min, and the stirring time is longer than 10 s.

5. The use of the asphalt plant reclaimed powder of claim 3 in shield construction, wherein: in the step A2, the injection pressure is 1-1.5 bar.

6. The application of the asphalt station recycling powder in shield construction is characterized in that: the slurry is used for forming a mud film for opening a cabin of a shield machine under pressure, and the used slurry is prepared by mixing and stirring the following components in percentage by mass: the recycled powder, the sodium bentonite and the water are = 3: 1: 12, and the addition amount of the polyacrylamide is 0.3-0.5 percent of the total mass of the solid powder.

7. The use of the asphalt plant reclaimed powder of claim 6 in shield construction, wherein: the method comprises the following construction steps:

b1: proportioning, namely placing the proportioned material in a bentonite tank of a shield machine and stirring to form slurry;

b2: when the shield machine is in pressure opening construction, injecting the slurry in the step B2 into the soil bin by using a bentonite injection system of the shield machine, discharging soil by using a screw conveyor under the condition of ensuring that the soil pressure at the upper part is not less than 1.2bar until the residue soil in the soil bin is removed, replacing the residue soil in the soil bin with the slurry mixed in the step B2, replacing for many times until the residue soil in the soil bin is completely replaced, and manually judging whether the residue soil in the soil bin is completely replaced by observing the soil discharging condition of the screw conveyor;

b3: closing the inserting plate of the bin door and the slag hole of the screw conveyor, and continuously injecting the slurry into the soil bin until the soil pressure at the upper part reaches 1.3-1.4 bar, and stopping slurry injection;

b4: starting an automatic pressure maintaining system, setting the pressure to be 1.4bar, soaking the slurry in the soil bin for 12 hours, and rotating the cutter head for a plurality of circles every 1 hour to form a mud film.

8. The application of the asphalt station recycling powder in shield construction is characterized in that: the method is used for filling the gap between the shield machine shell and the soil or for maintaining the soil pressure when the shield machine is stopped, and comprises the following steps:

c1: preparing materials: water glass, water, recycled powder, sodium bentonite, portland cement and polyacrylamide;

c2: preparation of a slurry I: uniformly mixing water glass and water = 1: 1 in a mass ratio, and stirring to form slurry I;

c3: preparing a slurry II: mixing the recycled powder, the sodium bentonite, the Portland cement and the water in a mass ratio of 50: 37.5: 12.5: 200, adding polyacrylamide in an amount of 0.3-0.5% by mass of the recycled powder, uniformly mixing, and stirring to form slurry II;

c4: through the clearance between with I thick liquid and II thick liquids through the pipeline pump sending to shield machine casing and soil of biliquid pump, the pump sending mass ratio of I thick liquid and II thick liquids is: 1: 3;

c5: and stopping grouting when the injected grout meets the construction requirements.

9. The application of the asphalt station recycling powder in shield construction is characterized in that: the slurry is used for preparing synchronous slurry, and is prepared by mixing and stirring the following ingredients in percentage by mass: cement, recovery powder, sodium bentonite, sand and water = 5: 1: 160: 9.

Technical Field

The invention relates to the technical field of shield construction, in particular to application of asphalt station recycling powder in shield construction.

Background

The asphalt mixing station processes asphalt, stone materials, binder and the like into asphalt mixture according to a certain mixing proportion, wherein the asphalt mixing is an important process for forming the asphalt mixture, and in the process, raw materials generate a large amount of dust particles seriously polluting the environment through a plurality of links such as transportation, transmission, mixing, heating and the like, and the particle size is usually less than 0.075mm, called recovered dust, called recovered powder or old powder for short.

Urban road construction and highway construction develop rapidly, 200 kilometers of road construction every year in a certain city, more than 160 ten thousand tons of asphalt mixture need to be produced by an asphalt mixing station, 7.2 ten thousand tons of recovery powder are produced, the stacking of the recovery powder occupies a large area of land, the land utilization rate is reduced, more adverse effects are brought to energy production, resource utilization and environmental protection, and if the recovery dust is not recycled, the serious problem of environmental pollution can be caused.

At present, the reclaimed powder of the asphalt station is generally treated according to waste, and is not effectively recycled basically. In the field of shield construction, the application of the recovered powder is very little, and the method has great potential value.

Disclosure of Invention

The invention aims to solve the technical problem of making up the defects of the prior art and provides an application method of the reclaimed powder of the asphalt station in shield construction, so that the reclaimed powder can be effectively recycled in the field of shield construction.

To solve the technical problems, the technical scheme of the invention is as follows:

the application of the asphalt station recycled powder in shield construction is used for treating gushing, and the used slurry is prepared by mixing and stirring the following components in percentage by mass: the ratio of the recovered powder to the water is 1: 1-1: 1.5, and the addition amount of the polyacrylamide is 0.3-0.5% of the mass of the recovered powder.

Further, recovery of fines to water = 1: 1.2.

Further, the method comprises the following construction steps:

a1: proportioning, namely placing the proportioned material in a bentonite tank of a shield machine and stirring to form slurry;

a2: when the shield construction process encounters a gushing stratum, injecting the slurry obtained in the step A2 into a soil bin by using a bentonite injection system of the shield machine;

a3: under the action of the slurry, the mud and the stones in the soil bin are gathered into a cluster and are deposited at the bottom of the soil bin;

a4: and D, conveying the mud and stone conglomerate obtained in the step A3 to a conveying belt through a screw conveyor, and forming a soil plug inside the screw conveyor so as to block the gushing.

Further, in the step A1, the stirring speed is 80-120 r/min, and the stirring time is longer than 10 s.

Further, in the step A2, the injection pressure is 1-1.5 bar.

The application of the asphalt station recovery powder in shield construction is used for forming a mud film of a shield machine with pressure and opening a bin, and the used mud is prepared by mixing the following components in percentage by mass: the recycled powder, the sodium bentonite and the water are = 3: 1: 12, and the addition amount of the polyacrylamide is 0.3-0.5 percent of the total mass of the solid powder.

Further, the method comprises the following construction steps:

b1: proportioning, namely placing the proportioned material in a bentonite tank of a shield machine and stirring to form slurry;

b2: when the shield machine is in pressure opening construction, injecting the slurry in the step B2 into the soil bin by using a bentonite injection system of the shield machine, discharging soil by using a screw conveyor under the condition of ensuring that the soil pressure at the upper part is not less than 1.2bar until the residue soil in the soil bin is removed, replacing the residue soil in the soil bin with the slurry mixed in the step B2, replacing for many times until the residue soil in the soil bin is completely replaced, and manually judging whether the residue soil in the soil bin is completely replaced by observing the soil discharging condition of the screw conveyor;

b3: closing the inserting plate of the bin door and the slag hole of the screw conveyor, and continuously injecting the slurry into the soil bin until the soil pressure at the upper part reaches 1.3-1.4 bar, and stopping slurry injection;

b4: starting an automatic pressure maintaining system, setting the pressure to be 1.4bar, soaking the slurry in the soil bin for 12 hours, and rotating the cutter head for a plurality of circles every 1 hour to form a mud film.

The application of the asphalt station recovery powder in shield construction is used for filling a gap between a shield machine shell and soil or maintaining the soil pressure when the shield machine stops, and comprises the following steps:

c1: preparing materials: water glass, water, recycled powder, sodium bentonite, portland cement and polyacrylamide;

c2: preparation of a slurry I: uniformly mixing water glass and water = 1: 1 in a mass ratio, and stirring to form slurry I;

c3: preparing a slurry II: mixing the recycled powder, the sodium bentonite, the Portland cement and the water in a mass ratio of 50: 37.5: 12.5: 200, adding polyacrylamide in an amount of 0.3-0.5% by mass of the recycled powder, uniformly mixing, and stirring to form slurry II;

c4: through the clearance between with I thick liquid and II thick liquids through the pipeline pump sending to shield machine casing and soil of biliquid pump, the pump sending mass ratio of I thick liquid and II thick liquids is: 1: 3;

c5: and stopping grouting when the injected grout meets the construction requirements.

The application of the asphalt station recycled powder in shield construction is used for preparing synchronous slurry, and the slurry is prepared by mixing and stirring the following ingredients in percentage by mass: cement, recovery powder, sodium bentonite, sand and water = 5: 1: 160: 9.

The invention can achieve the following beneficial effects:

1) when the asphalt station recycled powder is applied to the working condition of governing the gushing, the stirred slurry has certain fluidity, good workability and pumpability, the slurry is not dispersed when entering water, has certain water-resisting and anti-shearing properties, and has less components and low cost; the slurry can be continuously stirred in a bentonite tank of the shield machine, and continuous tunneling can be realized;

2) when the asphalt station recycled powder is applied to the working condition of forming a mud film for opening a cabin under pressure of a shield machine, the asphalt station recycled powder can replace most of sodium bentonite with higher cost in the conventional formula, so that the cost is greatly reduced; the formed mud membrane has a compact structure, is suitable for a high-permeability bottom layer, has water-resisting property, and is not easy to dilute and take away in a water-rich stratum;

3) when the asphalt station recycled powder is applied to filling a gap between a shield machine shell and soil or used for a working condition of soil pressure maintenance when the shield machine stops, the two liquids are mixed into a paste, the paste has anti-dilution property and water retaining property, is not easy to be diluted by water, has short condensation time and quick effect, the viscosity after condensation is 300-doped 450dPa.S, and the viscosity does not change along with the change of time;

4) when the asphalt station recycled powder is applied to preparation of synchronous slurry, the fly ash can be replaced, and compared with the synchronous slurry prepared from the fly ash, the asphalt station recycled powder has the advantages of short gelling time, high consolidation strength, good consistency and the like.

Detailed Description

The present invention will be described in further detail with reference to specific embodiments.

The recycled powder used in the following examples is transported to a shield construction site from an asphalt mixing station in bags, each bag is 50kg, and the particle size is less than or equal to 0.075 mm.