Expansive soil slope ecological protection system and construction method

Abstract

The invention discloses an expansive soil side slope ecological protection system and a construction method, and relates to the technical field of side slope prevention and control, the expansive soil side slope ecological protection system comprises a side slope body, an intercepting ditch arranged at the top of the side slope body, a pouring groove at the slope surface and a drainage ditch at the bottom; a water inlet groove is formed in the intercepting ditch, the intercepting ditch is connected to a storage box installed in the side slope through the water inlet groove, and the storage box communicates with the slope surface irrigation groove through a water outlet hole formed in one side. Through the arrangement of the intercepting ditch, the storage box and the irrigation groove, efficient collection, storage and on-demand release of rainwater are achieved, slope expansion and instability caused by rainwater permeation in rainy seasons are avoided, the problem of water shortage of vegetation in dry seasons is solved, vegetation survival is guaranteed, the improved mixture and a microorganism mineralization system achieve the synergistic effect, and the ecological environment is improved. The expansibility of the expansive soil can be reduced, the strength of the soil body can be enhanced, solid waste resource utilization is achieved, environmental pollution is reduced, and integrated protection of soil body improvement, structure reinforcement and ecological restoration is formed in cooperation with the biological matrix improvement layer and the vegetation layer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of slope prevention, in particular to an expansive soil slope ecological protection system and a construction method. BACKGROUND

[0002] Expansive soil is a special soil body with significant water absorption and expansion, water loss and shrinkage characteristics. Its volume change will produce a large expansion force and shrinkage crack, which can easily lead to slope instability and collapse, posing a serious threat to the safety of road, water conservancy, building and other engineering facilities. With the deepening of the concept of ecological protection, the prevention of expansive soil slope has shifted from traditional pure mechanical reinforcement to the direction of "combination of ecological protection and engineering stability", that is, while ensuring the safety of the slope structure, realizing vegetation restoration and ecological restoration, and reducing the disturbance to the natural environment. At present, the prevention of expansive soil slope needs to consider multiple requirements such as soil improvement (reducing expansibility), structure reinforcement (resisting deformation), rainwater management (avoiding water erosion) and vegetation survival (maintaining ecology).

[0003] The existing expansive soil slope protection technology has many limitations: the rainwater management mechanism is missing, most protection systems do not have an efficient rainwater collection and utilization system, and in the rainy season, soil instability may be caused by rainwater penetration, and in the dry season, vegetation may wither due to lack of water, which cannot balance the contradiction between preventing erosion and preserving vegetation. Moreover, the environmental friendliness of soil improvement materials is insufficient, and some improvement agents (such as cement and lime) can reduce expansibility, but they can damage the soil ecology and are difficult to achieve solid waste resource utilization; the application of new technologies such as microorganisms and mineralization is not mature, and there is a lack of collaborative design with the ecological vegetation layer, and the existing technology has problems such as unreasonable material ratio and complicated construction steps, which makes it difficult to balance construction efficiency and protection effect, and the environmental friendliness is insufficient. SUMMARY

[0004] The purpose of the present application is to provide an expansive soil slope ecological protection system and a construction method to solve the problems in the above background.

[0005] The purpose of the present application can be achieved by the following technical solutions: An expansive soil slope ecological protection system, comprising a slope body, a water interception ditch provided at the top of the slope body, a irrigation trench on the slope surface and a drainage ditch at the bottom; A water inlet is arranged in the water interception ditch, the water interception ditch is connected to a storage tank installed inside the slope through the water inlet, and the storage tank is communicated with the slope surface irrigation trench through a water outlet hole formed on one side, for collecting rainwater and irrigating vegetation.

[0006] As a further solution of the present application: a drainage groove is arranged at the middle of the top end of the storage tank for allowing rainwater to enter the inside of the storage tank; The drainage groove is slightly larger than the water inlet.

[0007] As a further scheme of the present application: the side of the slope is slidably connected with a baffle for controlling the rainwater flow in the irrigation groove.

[0008] As a further scheme of the present application: the inside of the storage box is fixedly connected with a flow guide plate for leading the rainwater to flow out of the water outlet hole; The inside of the storage box is fixedly connected with a positioning rod, and the middle part of the positioning rod is slidably connected with a connecting column, one end of the connecting column is fixedly connected with a flow baffle, and the other end of the connecting column is fixedly connected with a floating block; The positioning rod and the floating block are fixedly connected with a spring, and the spring is sleeved on the surface of the connecting column.

[0009] As a further scheme of the present application: further comprising a modified mixture prepared by mixing desulfurized gypsum, fly ash and soil according to specific mass fractions; A microbial mineralization system containing bacillus pasteurii for cementing soil particles; And an ecological protection layer composed of a biological matrix improvement layer and vegetation.

[0010] As a further scheme of the present application: in the modified mixture, the mass fraction of phosphogypsum is 19 parts, the mass fraction of fly ash is 1 part, and the mass fraction of soil is 40-50 parts in the dry state, and the soil is one or more of expansive soil, cohesive soil, silt, loam or planting soil.

[0011] As a further scheme of the present application: in the microbial mineralization system, the microbial solution is prepared by placing bacillus pasteurii in a culture medium, and the mixed solutes in the cementing solution include urea and calcium chloride.

[0012] As a further scheme of the present application: the biological matrix improvement layer is composed of expansive soil, biological organic fertilizer, biochar, plant fiber and slow-release fertilizer.

[0013] As a further scheme of the present application: the vegetation is combined by grass seeds and a mixed solution prepared by mixing an adhesion agent for promoting the growth of the grass seeds, wood fiber, fertilizer and auxin.

[0014] The construction method of the ecological protection of the expansive soil slope comprises the following steps: S1: testing the basic physical indicators of the soil body; S2: preparation of the culture medium; S3: preparation of the microbial solution; S4: preparation of the cementing solution; S5: preparation of the mixture; S6: preparation of the improved jet slurry; S7: laying of the vegetation net; S8: configuration of the grass seed mixed material; S9: slurry jet construction; S10: Covering maintenance.

[0015] The beneficial effects of this invention are: (1) This invention achieves efficient collection, storage and release of rainwater on demand by setting up intercepting ditches, storage boxes and irrigation troughs. It avoids slope expansion and instability caused by rainwater infiltration during the rainy season, solves the problem of vegetation water shortage during the dry season, ensures vegetation survival, and improves the synergistic effect of the mixture and microbial mineralization system. It can reduce the expansibility of expansive soil, enhance soil strength, realize the resource utilization of solid waste, reduce environmental pollution, and form an integrated protection of soil improvement, structural reinforcement and ecological restoration in combination with biological matrix improvement layer and vegetation layer. (2) The automatic control structure composed of the float, baffle and spring in the storage box of the present invention can automatically adjust the water inlet state according to the water level to achieve dynamic balance of rainwater storage; the baffle design makes it easy to manually control the irrigation time, flexibly respond to the needs of the dry season, and solve the problem of disorderly discharge or unusable rainwater in traditional protection. (3) In this invention, the microbial mineralization system utilizes Bacillus pasteurellii to bind soil particles, thereby enhancing the integrity of the soil. The culture medium is low-cost and environmentally friendly. The addition of desulfurized gypsum and fly ash to the improved mixture not only reduces the expansibility of expansive soil but also enables the reuse of solid waste, which is in line with the concept of green development. The design of the biological matrix improvement layer and the vegetation mixture optimizes soil fertility and vegetation growth environment, thereby improving the survival rate of vegetation. Attached Figure Description

[0016] The invention will now be further described with reference to the accompanying drawings.

[0017] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a partial cross-sectional structural diagram of the present invention; Figure 3 This is a partial structural schematic diagram of the present invention; Figure 4 This is a schematic diagram of the construction process of the present invention.

[0018] In the diagram: 1. Slope; 2. Interception ditch; 3. Filter plate; 4. Irrigation trough; 5. Baffle; 6. Inlet trough; 7. Storage tank; 8. Diversion trough; 9. Guide plate; 10. Baffle plate; 11. Positioning rod; 12. Connecting column; 13. Spring; 14. Float; 15. Outlet. Detailed Implementation

[0019] Clearly, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0020] Embodiment one Please refer to Figure 1 - Figure 4 As shown in the figure, the present application is an ecological protection system for expansive soil slope, which comprises a slope body 1, a water interception ditch 2 arranged at the top of the slope body 1, a slope surface irrigation groove 4 and a drainage ditch at the bottom; The water interception ditch 2 is provided with a water inlet groove 6, and the water interception ditch 2 is connected to a storage tank 7 installed inside the slope 1 through the water inlet groove 6, and a water outlet hole 15 opened on one side of the storage tank 7 is communicated with the slope surface irrigation groove 4, which is used for collecting rainwater and irrigating vegetation.

[0021] It should be noted that the irrigation groove 4 is provided in two sections, one of which is connected to the inside of the storage tank 7 and is inclined, and the other is flush with the slope surface of the slope 1, so that the rainwater can flow more easily along the irrigation groove 4.

[0022] Preferably, in the present application, a drainage groove 8 is arranged at the middle of the top end of the storage tank 7, which is used for making rainwater enter the inside of the storage tank 7. The drainage groove 8 is slightly larger than the water inlet groove 6.

[0023] Preferably, in the present application, a baffle 5 is slidably connected to one side of the slope 1, which is used for controlling the flow of rainwater in the irrigation groove 4.

[0024] It should be noted that the top of the baffle 5 is flush with the top surface of the slope 1, and a pull handle is folded inside the baffle 5, which is convenient for pulling the baffle 5.

[0025] Preferably, in the present application, a flow guide plate 9 is fixedly connected inside the storage tank 7, which is used for guiding rainwater to flow out of the water outlet hole 15. A positioning rod 11 is fixedly connected inside the storage tank 7, and a connecting column 12 is slidably connected to the middle of the positioning rod 11, one end of the connecting column 12 is fixedly connected with a flow baffle 10, and the other end of the connecting column 12 is fixedly connected with a floating block. A spring 13 is fixedly connected between the positioning rod 11 and the floating block, and the spring 13 is sleeved on the surface of the connecting column 12.

[0026] It should be noted that the flow guide plate 9 is inclined, which is convenient for guiding rainwater to the water outlet hole 15. The shape of the flow baffle 10 is communicated with the shape and size of the water inlet groove 6, and sealing strips are installed around the flow baffle 10, which is convenient for blocking the water inlet groove 6. The baffle 10 is initially arranged inside the storage tank 7.

[0027] In the implementation process, when it rains, rainwater falls into the water collecting ditch 2 after being filtered by the filter plate 3, and the water in the water collecting ditch 2 enters the storage tank 7 through the water inlet groove 6 and the drainage groove 8, so as to collect rainwater. When the water level rises, the floating block 14 in the storage tank 7 pushes the connecting column 12 and extrudes the spring 13, the connecting column 12 carries the baffle 10 and moves upward along the middle part of the positioning rod 11, when the water level reaches the high point inside the storage tank 7, the baffle 10 completely blocks the water inlet groove 6, so that the rainwater in the water collecting ditch 2 no longer enters the storage tank 7, and flows out from both sides. When it is a dry season, the folding handle of the baffle 5 is pulled, the baffle 5 is removed along the slope 1, the rainwater stored in the storage tank 7 flows into the irrigation groove 4 through the guide of the guide plate 9 and irrigates the soil of the slope 1, so as to avoid the withering of plants and improve the practicability. When the water level in the storage tank 7 decreases, the floating block 14 carries the connecting column 12 and the baffle 10 and moves along the middle part of the positioning rod 11 by the counterforce of the spring 13 and is collected into the storage tank 7, so that the water inlet groove 6 is not blocked, and rainwater can be collected again when it rains.

[0028] Embodiment two In the application, preferably, the improved mixture is prepared by mixing desulfurized gypsum, fly ash and soil according to specific mass fractions. The microbial mineralization system containing bacillus pasteurii is used for cementing soil particles. The ecological protection layer is composed of a biological matrix improvement layer and vegetation.

[0029] In the application, preferably, in the improved mixture, the mass fraction of phosphogypsum is 19 parts, the mass fraction of fly ash is 1 part, and the mass fraction of soil is 40-50 parts in the dry state, and the soil is one or more of expansive soil, cohesive soil, silt, loam or planting soil.

[0030] In the application, preferably, in the microbial mineralization system, the microbial solution is prepared by placing bacillus pasteurii in a culture medium, and the mixed solutes in the cementing solution include urea and calcium chloride.

[0031] In the application, preferably, the biological matrix improvement layer is composed of expansive soil, biological organic fertilizer, biochar, plant fiber and slow-release fertilizer.

[0032] In the application, preferably, the vegetation is combined by a mixed solution prepared by mixing grass seeds, an adhesion agent for promoting the growth of the grass seeds, wood fiber, fertilizer and auxin.

[0033] The ecological protection construction method for an expansive soil slope comprises the following steps: S1: Test of basic physical indexes of soil body; S2: Preparation of culture medium; S3: Preparation of microbial solution; S4: Preparation of cementing solution; S5: Preparation of mixture; S6: Preparation of improved jetting slurry; S7: Laying of vegetation net; S8: Preparation of grass seed mixture; S9: Jetting slurry construction; S10: Covering maintenance.

[0034] Specific construction method of the present application: S1: Test of basic physical indexes of soil body: the basic physical indexes of the soil body to be reinforced are tested according to the test specification in the Highway Soil Test Regulation (JTC E4-2007), mainly including the basic indexes of natural moisture content, density, pH value, liquid limit, plastic limit, plasticity index and free expansion rate of the soil body.

[0035] S2: Preparation of culture medium: the solutes of the culture medium mainly include 20 g / L of yeast paste, 20 g / L of ammonium sulfate and 0.13 mol / L of tris-hydroxymethyl aminomethane buffer. 10 parts of yeast paste, 5 parts of ammonium sulfate and 1.55 parts of tris-hydroxymethyl aminomethane buffer are weighed, and the above solutes are mixed with water in a mass ratio of 1:5 to prepare the liquid culture medium. Then a certain amount of sodium hydroxide solution is added to the liquid culture medium to adjust the pH value to about 9, and high-temperature sealed sterilization is performed in a high-pressure sterilization pot at 120℃, and then cooled to about 28℃.

[0036] S3: Preparation of microbial solution: the purchased bacteria in the state of freeze-dried powder are vacuum preserved in an ampoule bottle, and bacterial activation is performed. 1 part of Bacillus pasteurii is inoculated into the prepared culture medium mixed solution in a sterile environment of a super-clean bench in a volume fraction. The microbial solution is placed in a constant-temperature (28℃) incubator and oscillated at a speed of 220 r / min for 36 hours or more until the OD600 of Bacillus pasteurii in the solution is 3.5.

[0037] S4: Preparation of cementing solution: the solutes of the cementing solution mainly include calcium chloride and urea. According to the formula in mass fraction, 2 parts of urea and 2 parts of calcium chloride are weighed and dissolved in 1L of water in sequence, and stirred and mixed uniformly to obtain a cementing solution with a concentration of 2 mol / L. Since the dissolution of urea in water is an endothermic reaction and the dissolution of calcium chloride in water is an exothermic reaction, the reaction liquid obtained by mixing is overall exothermic, and after the exothermic reaction ends and the temperature returns to normal, the microbial solution is mixed and used.

[0038] S5 Preparation of the mixture: the main components of the mixture include desulfurization gypsum, fly ash and soil, which are considered in terms of mass fraction in dry state. Take 18 parts of desulfurization gypsum, 2 parts of fly ash and 40 parts of soil, mix and stir uniformly to form the mixture. The soil in the mixture can be expansive soil, silt, clay or planting soil.

[0039] S6 Preparation of the improved jet slurry: according to the formula in terms of volume fraction, take 500-1200 parts of the mixture, 1 part of the microbial solution and 10 parts of the cementing liquid, mix and stir uniformly according to a certain proportion, then add the cementing liquid and water and stir uniformly to form the improved jet slurry.

[0040] S7 Laying of the vegetation net: first, level the excavated slope and clean up the debris and other obstacles, set up drainage channels on the slope surface, water interception ditches on the top of the slope and drainage ditches at the bottom of the slope. Lay the nylon vegetation net on the expansive soil slope surface from top to bottom, extend the vegetation net by 40-80 cm on the top of the slope, bury it in the soil and compact it. Keep the net and the slope surface smooth and combined, and use U-shaped steel bars with a diameter of 6 mm or more to fix the vegetation net, wherein the U-shaped steel bars are about 15-30 cm long and 8 mm wide, the spacing between the U-shaped steel bars is about 1.5-2.5 m, and U-shaped nails or bamboo nails are used for auxiliary fixation.

[0041] S8 Preparation of the grass seed mixed material: mix and stir the grass seeds (about 25 grams per square meter for spraying and seeding), the adhesion agent for promoting growth, wood fiber, fertilizer, growth hormone, moisture retention agent and water according to a certain proportion to form a uniform grass seed mixed solution.

[0042] S9 Jet slurry construction: after the nylon vegetation net is laid, mix the improved slurry and the grass seed mixed solution uniformly, then use hydraulic jet to spray it onto the slope surface, the thickness of the slurry for each spraying is 4±1 cm, a total of 3 times, the total thickness of the slurry sprayed on the slope surface is not less than 12 cm, and the construction of the jet slurry is carried out in the order of upper part first, lower part later, left to right.

[0043] S10 Covering and maintenance: after the jet slurry construction is completed, cover the non-woven fabric on the slope surface to maintain the moisture of the slope surface and reduce the erosion of rainfall on the seeds, promote the growth of the seeds, if the temperature is too high, do not cover it to avoid the occurrence of diseases and pests, and when the lawn grows to about 5 cm, remove the non-woven fabric.

[0044] This construction method is simple and fast, which can meet the requirements of ecological greening, rainwater erosion resistance and prevention of shallow landslide of the expansive soil slope, and the desulfurization gypsum solid waste resource is reused, which is friendly to the environment and can save costs. The microbial culture uses a cheap culture medium, which not only has low cost, but also can solidify harmful elements after microbial improvement, reducing the impact on the ecological environment.

[0045] The above detailed description has shown, by way of illustration, the preferred embodiments of the application. It is, however, to be understood that this application is not to be construed as being limited to the embodiments set forth above and that modifications and improvements can be made to those embodiments without departing from the scope and spirit of the application.

Claims

1. An expansive soil slope ecological protection system, characterized in that, The slope body, a water intercepting ditch arranged on the top of the slope body, a pouring groove on the slope surface and a drainage ditch at the bottom; The water intercepting ditch is connected to a storage tank arranged inside the slope through a water inlet groove, and the storage tank is communicated with the pouring groove on the slope surface through a water outlet hole arranged on one side of the storage tank, so as to collect rainwater and irrigate vegetation.

2. The expansive soil slope ecological protection system according to claim 1, characterized in that, A drainage groove is arranged in the middle of the top end of the storage tank, so as to make rainwater enter the inside of the storage tank. The drainage groove is slightly larger than the water inlet groove.

3. The expansive soil slope ecological protection system according to claim 1, characterized in that, A baffle is slidably connected to one side of the slope, so as to control the flow of rainwater in the pouring groove.

4. The expansive soil slope ecological protection system according to claim 1, characterized in that, A flow guide plate is fixedly connected to the inside of the storage tank, so as to guide rainwater to flow out of the water outlet hole. A positioning rod is fixedly connected to the inside of the storage tank, a connecting column is slidably connected to the middle of the positioning rod, one end of the connecting column is fixedly connected to a flow baffle, and the other end of the connecting column is fixedly connected to a floating block. A spring is fixedly connected between the positioning rod and the floating block, and the spring is sleeved on the surface of the connecting column.

5. The expansive soil slope ecological protection system according to claim 1, characterized in that, The improved mixture is mixed by desulfurized gypsum, fly ash and soil according to specific mass fractions; A microbial mineralization system containing bacillus pasteurii is used to cement soil particles; And an ecological protection layer composed of a biological matrix improvement layer and vegetation.

6. The expansive soil slope ecological protection system according to claim 5, characterized in that, In the improved mixture, the mass fraction of phosphogypsum is 19 parts, the mass fraction of fly ash is 1 part, and the mass fraction of soil is 40-50 parts in a dry state, and the soil is one or more of expansive soil, cohesive soil, silt, loam or planting soil.

7. The expansive soil slope ecological protection system according to claim 5, characterized in that, In the microbial mineralization system, the microbial solution is prepared by placing bacillus pasteurii in a culture medium, and the mixed solutes in the cementing solution include urea and calcium chloride.

8. The expansive soil slope ecological protection system according to claim 5, characterized in that, The biological matrix improvement layer is composed of expansive soil, biological organic fertilizer, biochar, plant fiber and slow-release fertilizer.

9. The expansive soil slope ecological protection system according to claim 5, characterized in that, The vegetation is composed of a mixture of grass seeds and a mixed solution of an adhesion agent, wood fiber, fertilizer and auxin for promoting the growth of the grass seeds.

10. The construction method of the ecological protection of the expansive soil slope, using the ecological protection system of the expansive soil slope according to any one of claims 1-9, characterized in that, The method comprises the following steps: S1: basic physical index test of soil body; S2: preparation of culture medium; S3: preparation of microbial solution; S4: preparation of cementing solution; S5: preparation of mixture; S6: preparation of improved jet slurry; S7: laying of vegetation net; S8: preparation of grass seed mixture; S9: slurry jetting construction; S10: covering and curing.

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