CN115492076A - Method for implementing ecological slope protection by combining urease with fiber and solid waste - Google Patents

Abstract

The invention discloses an ecological slope protection implementation method of urease and fiber combined with solid waste, which comprises the following steps: step 1), removing gravel rubbish on the surface of the slope for treatment, digging out planting holes at equal intervals, and sowing plant seeds in the slope In the planting hole, re-cover and level the soil; step 2), spread high-calcium fly ash on the planting hole, and then use the sprayer to mix soybean extract, carbonamide solution, calcium source solution and fiber in proportion Spray the mixed homogeneous substance on the slope, and repeat the spraying of the homogeneous substance at regular intervals; step 3), after the seeds germinate, spray the homogeneous substance on the slope surface again, and lay a layer on the surface Layer non-woven fabric for maintenance; the invention combines fibers to effectively utilize waste concrete blocks and high-calcium fly ash, which can increase the survival rate of vegetation on the slope, reduce soil erosion on the slope, and have a wide range of raw materials, The processing method is simple and can be used for industrialized production promotion.

Description

A kind of ecological slope protection implementation method of urease and fiber combined with solid waste

technical field

The invention relates to the technical field of slope ecological protection engineering, in particular to an implementation method of ecological slope protection in which urease cooperates with fibers to combine solid waste.

Background technique

Existing solid waste treatment of discarded concrete blocks includes physical and chemical methods. The physical method is to remove the cement mortar on the outer layer of the concrete block by external force. The most common external force is heating and grinding. However, the disadvantage of this method is that high temperature heating will damage the natural aggregate and reduce its performance. The chemical method includes the use of chemical substances for spraying, drying and other treatments to improve the surface pore structure and achieve the effect of improving the performance of the substrate. The disadvantage is that the economic cost is too large and has no practical application value. It is very necessary to find a safe, effective and environment-friendly method to deal with this kind of solid waste.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned deficiencies, provide a kind of ecological slope protection implementation method of urease and fiber combined with solid waste, combine solid waste with emerging biological slope consolidation technology to achieve the purpose of vegetation slope protection, avoid the waste of manpower and material resources in the existing slope protection technology Resources, long cycle, not conducive to plant growth, not environmentally friendly and other shortcomings.

The present invention is for solving above-mentioned technical problem, and the technical solution adopted is: a kind of ecological slope protection implementing method of urease synergistic fiber binding solid waste, it comprises the following steps:

Step 1), remove the gravel rubbish on the slope surface, dig out the planting holes at equal intervals, sow the plant seeds into the planting holes, cover and level the soil again;

Step 2), spread high-calcium fly ash at the planting hole, and then use a sprayer to spray the homogeneous mixture of soybean extract, carbonamide solution, calcium source solution and fiber on the slope, And repeat the spraying of this homogeneous substance at regular intervals;

Step 3), after the seeds germinate, spray the homogeneous substance on the slope again, and lay a layer of non-woven fabric on the surface for maintenance.

Preferably, in the step 1), the plant seeds are Bermudagrass seeds, which are washed with pure water, dried in the sun, and sown at a seeding density of 8-12g/m ² , with equal intervals of 15-20cm between adjacent seeds. The distance between adjacent planting holes is 15-20cm.

Preferably, the extraction method of the soybean extract in the step 2) is: wash the soybeans with pure water and grind them into soybean powder in a wall breaking machine, and pass through a 200-mesh sieve, and the weight ratio is 1:25 Mix soybean powder and distilled water, stir thoroughly for 30 minutes and let it stand for 6 hours until the soybean dregs settle. Take the soybean solution and place it in a centrifuge at 3000r/min for 15 minutes to obtain a soybean extract, which is stored at 4°C spare.

Preferably, the method for obtaining high-calcium fly ash in said step 2) is: buy lignite and sub-bituminous coal as fuel and discharge high-calcium fly ash in local factories, and mix sodium hydroxide and high-calcium fly ash by weight The ratio is 0.2%: 1 and put into a ball mill for ball milling.

Preferably, the method for extracting the calcium source solution in step 2) is: buy and dismantle the waste concrete block from the construction site construction project, use a grinder to crush, sieve through a 1mm standard geotechnical sieve, and mix the sieved concrete with 2mol/L hydrochloric acid is mixed according to the ratio of 1:2, and 1mol/L sodium hydroxide solution is added to the mixed solution to adjust the pH of the mixed solution to 6.5-7.0, and then the mixed solution is placed in a centrifuge for Centrifuge at a speed of 3000 r/m for 15 minutes, and extract the supernatant as a calcium source solution.

Preferably, the fiber in the step 2) is selected from wood fiber or palm fiber, the fiber is first washed with deionized water with pH=7, and then treated with oil agent, the ratio of oil coating weight to fiber weight is 0.3%, The thickness of the coated coating is about 100nm, and finally the fiber is cut to about 1.7-2.2cm with scissors and mixed in the homogeneous substance.

Preferably, the mixing ratio of soybean extract, carbonamide solution and calcium source solution in the step 2) is 1:0.5:0.5, the amount of sprayed fiber is 8-10g/m ² , and the amount of high-calcium fly ash spread It is 600-800g/m ² .

Preferably, the amounts of soybean extract, carbonamide solution and calcium source solution sprayed on the slope each time in step 2) and step 3) are 1.8-2.2L/m ² and 0.8-1.2L/m ² respectively and 0.8-1.2 L/m ² .

The beneficial effects of the present invention are:

(1) The present invention combines the urease-induced calcium carbonate precipitation technology with waste concrete blocks and high-calcium fly ash to get rid of the inability to process waste and old concrete blocks in the construction industry and the inability to process high-calcium fly ash produced by coal combustion in industrial production. The shortcomings of being used on a large scale and being discarded endanger the environment. The production cost of each raw material is low, and after grinding, each molecule can penetrate the soil of different substrates, and the effect can reach deeper soil layers, and it is not easy to be blocked. The excess urease can It degrades over time in the soil, and improves the mechanical properties of the slope under natural conditions without destroying the original slope, thereby avoiding small-scale landslides and other hazards.

(2) The present invention combines urease-induced calcium carbonate precipitation technology with fiber, and fiber provides the nucleation site of free urease, so that calcium carbonate crystals are easy to generate, and the calcium carbonate and soil particles that can be attached to the fiber surface form "fiber-soil" Particle-Calcium Carbonate" three-dimensional network structure, the pores between soil particles are filled, and calcium carbonate crystal bridges bond fibers and soil particles at both ends of the fiber and on the surface to achieve overall stress transfer and limit soil deformation under external forces , can also reduce the stress concentration on the surface of the slope and enhance the anti-slip ability of the soil.

(3) The present invention utilizes the waste and old concrete block as calcium source after being processed, and the calcium carbonate crystal composition of generation is: the inside is calcite, and the outside is the circulation aggregate crystal of irregular polyhedron block, and the surface is concavo-convex interlaced, can be in the soil particle pore attract each other to form a dense network structure. Urease induces the NH4+ generated during the calcium carbonate precipitation reaction to enter the interior of the cyclic aggregate crystal structure and neutralize the permanent negative charge on its surface due to the replacement reaction, making the low-valence, large-radius ions and structural units in the soil attached to the soil particles , so that it has a certain degree of adsorption, thereby strengthening the skeleton group structure of the original molecule, and combining with high-calcium fly ash to promote the formation of hydration gelling substances. Compared with the chemical calcium source, the waste concrete calcium source is 1/3 cheaper in production cost, the amount of calcium carbonate produced is not significantly different from that of the most commonly used chemical calcium source-calcium chloride, and the mechanical properties such as shear strength after reinforcement are all the same. Significant differences.

(4) Under the conditions of urease-catalyzed hydrolysis of urea and generation of calcium carbonate from calcium source solution, the molecular structure of silica and alumina contained in high-calcium fly ash will be destroyed, covalent bonds will be broken, and a large number of active unsaturated bonds will be generated. Combined with calcium ions to generate hydration gelling products, and at the same time dissolve the amorphous substances in the pores, reduce the resistance of the pores, and the H+ with a small radius will replace the cations with a large radius, thereby expanding the pore size and improving the hydration gel. Adsorption capacity of coagulation products, hydration gelation products and fiber-calcium carbonate crystals form a chain structure with ionic bonds and covalent bonds as the main linking force, and van der Waals force as the auxiliary linking force. Each bond in the chain structure compound The larger the vector sum of the polarities, the greater the intermolecular force, which can effectively enhance the wind resistance and strain relaxation of the soil surface.

(5) The high-calcium fly ash itself has a porous honeycomb structure, combined with the urease-induced calcium carbonate precipitation technology, can increase the contact angle of water in the soil particle pores of the slope after encountering water, and reduce the water in the pores. Negative pressure increases the porosity of the soil after reinforcement and reduces the problem of low plant survival rate caused by high-strength reinforcement of the soil.

(6) In the early stage of application, the shear strength of the slope is low. Adding fiber as a reinforcing material can effectively reduce the instability caused by excessive f-CaO in high-calcium fly ash and the urease-induced calcium carbonate precipitation technology can affect the slope in the early stage of application. The width and spacing of cracks generated on the slope surface, the disordered arrangement of fibers can be combined with calcium carbonate crystals, on the one hand, it can be filled into the pores of high-calcium fly ash, and the combination is tighter, which improves the durability of the action, and on the other hand, promotes high-calcium fly ash The formation of CSH gel in fly ash, and the free water in the adsorbed soil is concentrated in the gel pores with a diameter less than 10nm in the hydration gelling product generated by high calcium fly ash, thereby improving the capillary pores, fine The interconnected critical pore network prevents deformation of the soil due to water loss.

(7) The invention combines fibers to effectively utilize waste concrete blocks and high-calcium fly ash, which can increase the survival rate of vegetation on the slope, reduce soil erosion on the slope, and have a wide range of raw materials and simple processing methods. Can be used for industrialized production promotion.

Description of drawings

Fig. 1 is the curve change figure of embodiment and comparative example in the present invention.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. A kind of ecological slope protection implementation method of urease synergistic fiber binding solid waste, it comprises the steps:

Step 1), remove the gravel rubbish on the slope surface, dig out the planting holes at equal intervals, sow the plant seeds into the planting holes, cover and level the soil again;

Step 2), spread high-calcium fly ash at the planting hole, and then use a sprayer to spray the homogeneous mixture of soybean extract, carbonamide solution, calcium source solution and fiber on the slope, And repeat the spraying of this homogeneous substance at regular intervals;

Step 3), after the seeds germinate, spray the homogeneous substance on the slope again, and lay a layer of non-woven fabric on the surface for maintenance.

Preferably, in the step 1), the plant seeds are Bermudagrass seeds, which are washed with pure water, dried in the sun, and sown at a seeding density of 8-12g/m ² , with equal intervals of 15-20cm between adjacent seeds. The distance between adjacent planting holes is 15-20cm.

Preferably, the extraction method of the soybean extract in the step 2) is: wash the soybeans with pure water and grind them into soybean powder in a wall breaking machine, and pass through a 200-mesh sieve, and the weight ratio is 1:25 Mix soybean powder and distilled water, stir thoroughly for 30 minutes and let it stand for 6 hours until the soybean dregs settle. Take the soybean solution and place it in a centrifuge at 3000r/min for 15 minutes to obtain a soybean extract, which is stored at 4°C spare.

Preferably, the method for obtaining high-calcium fly ash in said step 2) is: buy lignite and sub-bituminous coal as fuel and discharge high-calcium fly ash in local factories, and mix sodium hydroxide and high-calcium fly ash by weight The ratio is 0.2%: 1 and put into a ball mill for ball milling.

Preferably, the method for extracting the calcium source solution in step 2) is: buy and dismantle the waste concrete block from the construction site construction project, use a grinder to crush, sieve through a 1mm standard geotechnical sieve, and mix the sieved concrete with 2mol/L hydrochloric acid is mixed according to the ratio of 1:2, and 1mol/L sodium hydroxide solution is added to the mixed solution to adjust the pH of the mixed solution to 6.5-7.0, and then the mixed solution is placed in a centrifuge for Centrifuge at a speed of 3000 r/m for 15 minutes, and extract the supernatant as a calcium source solution.

Preferably, the fiber in the step 2) is selected from wood fiber or palm fiber, the fiber is first washed with deionized water with pH=7, and then treated with oil agent, the ratio of oil coating weight to fiber weight is 0.3%, The thickness of the coated coating is about 100nm, and finally the fiber is cut to about 1.7-2.2cm with scissors and mixed in the homogeneous substance. In this embodiment, washing can increase the cellulose of the fiber, and oil treatment can increase the fracture resistance of the fiber. Because the adhesion of the fiber surface is strong, the oil film loss during the mixing process can be ignored, and the oil agent is epoxy soybean oil. .

Preferably, the mixing ratio of soybean extract, carbonamide solution and calcium source solution in the step 2) is 1:0.5:0.5, the amount of sprayed fiber is 8-10g/m ² , and the amount of high-calcium fly ash spread It is 600-800g/m ² .

Preferably, the amounts of soybean extract, carbonamide solution and calcium source solution sprayed on the slope each time in step 2) and step 3) are 1.8-2.2L/m ² and 0.8-1.2L/m ² respectively and 0.8-1.2 L/m ² .

Below in conjunction with embodiment and comparative example concretely illustrate the implementation process of this method and implementation effect thereof:

Describe with specific embodiment below:

Embodiment 1 (the present invention)

Taking a 5m×5m sample plot on the 1# slope with a slope height of 25m and a slope of 30° at a hydropower station slope greening site as an example, step 1 removes rubbish such as gravel on the slope, and step 2 removes rubbish at intervals. Dig out the seed planting hole at 20cm, sow the bermudagrass seeds washed with deionized water, the sowing density is 10g/m ² , step 3, spread high-calcium fly ash on the surface of the sample land at a content of 750g/m ² , Use a sprayer to spray a homogeneous substance consisting of soybean extract, carbamide solution, calcium source solution and palm fiber every 3 days, with concentrations of 2.0L/m ² , 1.0L/m ² , and 1.0L/m ² and 8g/m ² , after the seeds germinated, the homogeneous substance composed of soybean extract, carbonamide solution, calcium source solution and palm fiber was sprayed on the plot again, the concentrations were 2.0L/m ² and 1.0L/ m ² , 1.0L/m ² and 8g/m ² , the soil vegetation coverage, surface shear strength, porosity, organic matter, soil separation ability, and the number of bermudagrass seeds per square meter were measured before each injection.

Comparative example 1 (no high calcium fly ash)

Taking a sample plot of 5m×5m on the 2# slope with a slope height of more than 25m and a slope of 30° in a hydropower station slope greening site as an example, step 1 removes rubbish such as gravels on the slope, step 2 Dig out the seed planting hole at an interval of 20cm, sow the bermudagrass seeds washed with deionized water, the sowing density is 10g/m ² , and step 3 uses a sprayer to spray the soybean extract, carboxamide solution, calcium The homogeneous substance composed of source solution and palm fiber, the concentration is 2.0L/m ² , 1.0L/m ² , 1.0L/m ² and 8g/m ² solution, carboamide solution, calcium source solution and palm fiber, the concentrations are 2.0L/m ² , 1.0 L/m ² , 1.0L/m ² and 8g/m ² respectively. The soil vegetation coverage, surface shear strength, porosity, organic matter, soil separation ability, and the number of bermudagrass seeds per square meter were measured before each injection.

Comparative example 2 (no concrete calcium source solution)

Taking a 5m×5m sample plot on the 1# slope with a slope height of 25m and a slope of 30° at a hydropower station slope greening site as an example, step 1 removes rubbish such as gravel on the slope, and step 2 removes rubbish at intervals. Dig out the seed planting hole at 20cm, sow the bermudagrass seeds washed with deionized water, the sowing density is 10g/m ² , step 3, spread high-calcium fly ash on the surface of the sample land at a content of 750g/m ² , Use a sprayer to spray a homogeneous substance composed of soybean extract, carboamide solution and palm fiber every 3 days, the concentrations are 2.0L/m ² , 1.0L/m ² and 8g/m ² respectively, until the seeds germinate Afterwards, the homogeneous substance composed of soybean extract, carbonamide solution and palm fiber was sprayed again on the sample plot, the concentrations were 2.0L/m ² , 1.0L/m ² and 8g/m ² respectively, and the soil was tested before each injection. Vegetation coverage, surface shear strength, porosity, organic matter, soil separation capacity, and the number of bermudagrass seeds per square meter.

Comparative example 3 (no fiber)

Take a 5m×5m sample plot on the 4# slope with a slope height of more than 25m and a slope of 30° in a hydropower station slope greening site as an example. Step 1 removes rubbish such as gravel on the slope, and Step 2 Dig out the seed planting hole at an interval of 20cm, sow the bermudagrass seeds washed with deionized water, the sowing density is 10g/m ² , step 3 first spread high-calcium fly ash on the surface of the sample land at a content of 750g/m ² , Every 3 days, a sprayer was used to spray a homogeneous substance composed of soybean extract, carbonamide solution and calcium source solution, with concentrations of 2.0L/m ² , 1.0L/m ² and 1.0L/m ² respectively. After the seeds germinated, the homogeneous substance composed of soybean extract, carboamide solution and calcium source solution was sprayed again on the sample plot, with concentrations of 2.0L/m ² , 1.0L/m ² , and 1.0L/m ² , respectively. The soil vegetation coverage, surface shear strength, porosity, organic matter, soil separation ability, and the number of bermudagrass seeds per square meter were measured before each injection.

Comparative example 4 (blank)

Taking a sample plot of 5m×5m on the 3# slope with a slope height of more than 25m and a slope of 30° in a hydropower station slope greening site as an example, step 1 removes rubbish such as gravels on the slope, step 2 Dig out the seed planting hole at an interval of 20cm, sow the bermudagrass seeds washed with deionized water, the sowing density is 10g/m ² , step 3 first spread high-calcium fly ash on the surface of the sample land at a content of 750g/m ² , Every 3 days, use a sprayer to spray a homogeneous substance consisting of soybean extract and carbonamide solution, with concentrations of 2.0L/m ² and 1.0L/m ² respectively. After the seeds germinate, spray again on the sample plot The homogeneous substance composed of soybean extract and carbonamide solution, the concentrations are 2.0L/m ² and 1.0L/m ² respectively, and the soil vegetation coverage, surface shear strength, porosity, organic matter, soil Separation ability, number of Bermudagrass seeds per square meter.

Compare above-mentioned embodiment and comparative example, data is as follows:

Test method and reference standard: Vegetation coverage adopts sampling acupuncture method, calculates the percentage of the vertical projected area of the aboveground part of the overall plant community or each individual and the ratio of the sample square area; the surface shear strength test is based on the soil engineering test method standard ( GB/T 50123-1999), measured by micro-surface cross shear instrument; porosity is measured by density test method according to the standard of geotechnical test method (GB/T 50123-1999); organic matter is measured by flow analyzer; soil separation ability It is obtained by calculating the mass difference before and after weighing in the scour test after sampling by the ring knife method.

As can be seen from the above comparative data, the vegetation coverage ratio of the embodiment in 30 days has increased by 2.62 times, the shear strength of the soil body surface has increased by 12kPa, and the porosity has decreased by 12.2%, and the content of the organic matter of the soil body has increased the most The soil separation ability index representing soil anti-scourability decreased by 9.74 times, and the smaller the soil separation ability, the better the soil anti-scourability, and the number of bermudagrass plants per square meter also had a greater increase compared with the control group. It shows that an ecological slope protection implementation method of urease and fiber combined with solid waste can significantly improve the performance of soil erosion resistance and shear strength, and the improvement of organic matter content provides an excellent environment for better growth of vegetation on the slope. There is an enhanced protective effect on the slope, and the root-soil complex formed by the plant root system and the soil significantly improves the ability of the slope to resist surface erosion, gully erosion, and rain erosion.

The above-mentioned embodiments are only preferred technical solutions of the present invention, and should not be regarded as limitations on the present invention. The embodiments in the present application and the features in the embodiments can be combined arbitrarily with each other if there is no conflict. The scope of protection of the present invention shall be the technical solution described in the claims, including equivalent replacements for the technical features in the technical solution described in the claims. That is, equivalent replacement and improvement within this range are also within the protection scope of the present invention.

Claims (8)

1. a kind of ecological slope protection implementation method that urease synergistic fiber combines solid waste, is characterized in that: it comprises the steps: Step 1), remove the gravel and rubbish on the slope surface, dig out planting holes at equal intervals, sow plant seeds into the planting holes, cover and level the soil again; Step 2), spread high-calcium fly ash on the planting hole, and then use a sprayer to spray the homogeneous mixture of soybean extract, carbonamide solution, calcium source solution and fiber on the slope. And repeat the spraying of this homogeneous substance at regular intervals; Step 3) After the seeds germinate, spray the homogeneous substance on the slope again, and lay a layer of non-woven fabric on the surface for maintenance. 2. The ecological slope protection implementation method of urease and fiber combined with solid waste according to claim 1, characterized in that: in the step 1), the plant seeds are bermudagrass seeds, which are washed with pure water and dried in the sun Sowing is carried out, the sowing density is 8-12 g/m ² , the equal interval between adjacent seeds is 15-20 cm, and the distance between adjacent planting holes is 15-20 cm. 3. The ecological slope protection implementation method of urease and fiber combined with solid waste according to claim 1, characterized in that: the extraction method of the soybean extract in the step 2) is: wash the soybeans with pure water and place them Grind soybean powder in a wall breaker, pass through a 200-mesh sieve, mix soybean powder and distilled water according to the weight ratio of 1:25, stir thoroughly for 30 minutes, let it stand for 6 hours, and then settle the soybean dregs. Take the soybean solution and place it in Centrifuge at 3000 r/min for 15 minutes in a centrifuge to obtain a soybean extract, which is stored at 4°C for future use. 4. The implementation method of ecological slope protection of a kind of urease synergistically combined with fiber and solid waste according to claim 1, characterized in that: the method for obtaining medium and high calcium fly ash in the step 2) is: buying lignite and sub-bituminous coal in local factories For the high-calcium fly ash discharged as fuel, sodium hydroxide and high-calcium fly ash are put into a ball mill at a weight ratio of 0.2%:1 for ball milling. 5. The implementation method of ecological slope protection of a kind of urease synergistic fiber combined with solid waste according to claim 1, characterized in that: the extraction method of the calcium source solution in step 2) is: buying and dismantling waste concrete blocks from the construction site , use a grinder to crush, sieve through a 1 mm standard geotechnical sieve, mix the sieved concrete with 2 mol/L hydrochloric acid at a ratio of 1:2, and add 1 mol/L hydrochloric acid to the mixed solution sodium hydroxide solution to adjust the pH of the mixed solution to 6.5-7.0, then place the mixed solution in a centrifuge at a speed of 3000 r/m for 15 minutes, and extract the supernatant as a calcium source solution. 6. The ecological slope protection implementation method of a kind of urease synergistic fiber combined with solid waste according to claim 1, characterized in that: the fiber in the step 2) is selected from wood fiber or palm fiber, and the fiber is first used with pH=7 Wash with deionized water, and then carry out oil treatment. The ratio of oil coating weight to fiber weight is 0.3%, and the thickness of the coated coating is about 100 nm. Finally, use scissors to cut the fiber to about 1.7-2.2 cm and mix it evenly. in matter. 7. a kind of ecological slope protection implementation method of urease synergistic fiber binding solid waste according to claim 1, is characterized in that: in described step 2), the mixing ratio of soybean extract, carbonamide solution and calcium source solution is 1: 0.5:0.5, the amount of spraying fiber is 8-10 g/m ² , and the amount of high-calcium fly ash spreading is 600-800 g/m ² . 8. The implementation method of ecological slope protection with urease and fiber combined with solid waste according to claim 1 or 7, characterized in that: in step 2) and step 3), the soybean extract sprayed on the slope each time, The amounts of the carboxamide solution and the calcium source solution are 1.8-2.2 L/m ² , 0.8-1.2 L/m ² and 0.8-1.2 L/m ² , respectively.

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