Ecological protection structure for red sandstone cutting slope and construction method

Abstract

The application discloses a kind of red sandstone cutting slope ecological protection structure and construction method, belong to slope engineering technical field.The structure includes excavation exposed slope, deep frame beam, positioning pile, slope foot retaining wall, fiber waterproof mortar layer, flexible pressure-reducing resistance layer, waterproof root-resistant layer, planting soil layer, W-OH scouring prevention layer, water interception ditch and drainage ditch;The deep frame beam is embedded on excavation exposed slope by positioning pile;The slope foot retaining wall is set in the bottom of excavation exposed slope;The slope surface of excavation exposed slope is sequentially provided with fiber waterproof mortar layer, flexible pressure-reducing resistance layer, waterproof root-resistant layer, planting soil layer and W-OH scouring prevention layer;The top of excavation exposed slope is provided with water interception ditch;The bottom of excavation exposed slope is provided with drainage ditch.The beneficial effect is that the structure can effectively prevent the influence of rainwater on red sandstone slope, uses low-carbon environmental protection type material and assembly type construction technology, construction efficiency is high, and ecological protection effect is good.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of slope engineering, and particularly relates to a red sandstone cutting slope ecological protection structure and a construction method. BACKGROUND

[0002] Red sandstone has unique color and texture, mainly red, dark red or brownish red, relatively loose texture, high porosity, relatively low strength, strong water absorption, swelling, easy to soften and disintegrate when encountering water, and the strength is greatly affected by the change range of water content, so it is more easily affected by weathering in the natural environment, and the durability is relatively weak. In the red sandstone cutting slope, rainwater becomes an important factor affecting the stability of the slope, and the stability of the slope is directly related to the safety of infrastructure and transportation.

[0003] At present, the research at home and abroad mainly focuses on using red sandstone as a building material as a filler for highways, dams and other infrastructure, while the research on the support and ecological protection of red sandstone slopes is relatively less, and most of the support of red sandstone slopes is to learn from the traditional rock slope flexible reinforcement measures such as anchor rod or anchor cable, and the ecological protection usually uses methods such as vegetation groove, vegetation belt, hanging net spray, artificial vegetation, etc. However, for red sandstone slopes, the construction of anchor rods or anchor cables disturbs the deep rock layers and easily leads to air and rainwater infiltration, thus causing rock disintegration and frost heaving rupture; at the same time, in ecological restoration, the ecological restoration layer of the slope is difficult to adhere firmly to the slope surface, aggravating soil erosion, the fertility of the ecological restoration layer is not durable enough, the water retention of the red sandstone slope is poor, which is not conducive to the growth of vegetation, and other problems exist; the plant root system grows thick in the rock fissure, which can generate 1.0-1.5MPa pressure on the two walls of the fissure, eventually leading to rock rupture and disintegration.

[0004] In order to promote the high-quality green development of the construction industry, it is urgent to seek a low-carbon, energy-saving and environmentally friendly cementing material to replace or reduce the use of cement in traditional slope support. The use of geopolymer (geopolymer) has the following three advantages: (1) geopolymer does not need high-temperature calcination, the production process has low energy consumption, less emission of toxic gases and harmful substances, and can reduce carbon emissions by about 80% compared with cement; (2) the raw materials of geopolymer are mainly fly ash, slag and other industrial by-products, which can reduce the environmental impact of industrial solid waste; (3) geopolymer also has the advantages of high strength, fast hardening, good resistance to erosion and water permeability. At the same time, the use of steel fibers made from waste tires to make waste tire steel fiber UHPC can effectively reduce the cost of UHPC and realize the recycling of solid waste.

[0005] Therefore, there is an urgent need for a low-carbon, energy-saving, flexible yielding and resistance reducing support structure that can effectively reduce the disturbance to the red sandstone slope and reduce the damage of swelling force to the support structure, and at the same time has a durable fertility, external water retention and internal waterproof, and root system puncture prevention and other ecological protection systems. SUMMARY

[0006] The purpose of the embodiment of the present application is to provide a red sandstone cutting slope ecological protection structure and construction method, which has a short drainage path and good waterproof effect. The deep frame beams are arranged in a rhombus shape with the long diagonal perpendicular to the slope foot, which is conducive to the rapid convergence and drainage of rainwater, avoiding the problems of poor drainage and long drainage path of traditional square frame beams. By setting a root-resistant layer, a high-concentration modified hydrophilic polyurethane flexible pressure-allowing and resistance-reducing layer, a seepage-proof coating and a series of seepage-proof and erosion-prevention measures, the rainwater infiltration and the disintegration and degradation of red sandstone are effectively avoided, and the stability of the slope is ensured, thereby at least one technical problem involved in the background art can be solved.

[0007] In order to solve the above technical problems, the present application is implemented as follows:

[0008] The embodiment of the present application provides a red sandstone cutting slope ecological protection structure, which comprises an excavated bare slope, a deep frame beam, a positioning pile, a slope foot retaining wall, a fiber waterproof mortar layer, a flexible pressure-allowing and resistance-reducing layer, a waterproof root-resistant layer, a planting soil layer, a W-OH erosion-prevention layer, a water interception ditch and a drainage ditch; the deep frame beam is embedded on the excavated bare slope through the positioning pile, the deep frame beam comprises a deep beam, a foamed geopolymer concrete and a positioning pile, the positioning pile is in a rhombus matrix and is inserted into the excavated bare slope, the deep beam is arranged between two adjacent positioning piles and is spliced with the side surface of the positioning pile at the end, and the foamed geopolymer concrete is filled in the cavity between the deep beam and the soil body of the excavated bare slope; the slope foot retaining wall is arranged at the bottom of the excavated bare slope; the fiber waterproof mortar layer, the flexible pressure-allowing and resistance-reducing layer, the waterproof root-resistant layer, the planting soil layer and the W-OH erosion-prevention layer are sequentially arranged on the slope surface of the excavated bare slope; and the water interception ditch and the drainage ditch are respectively arranged at the top and the bottom of the excavated bare slope.

[0009] Optionally, the deep frame beam is prefabricated from geopolymer concrete with a strength of 40-60 MPa, and the geopolymer concrete comprises 180-200 parts of slag, 50-80 parts of fly ash, 25-35 parts of silica fume, 40-60 parts of solid sodium hydroxide, 900-920 parts of crushed stone, 450-500 parts of medium sand, 85-100 parts of mixing water and 20-30 parts of waste tire steel fiber.

[0010] Optionally, the foamed geopolymer concrete for filling has the same proportion as the geopolymer concrete in the deep frame beam and is made by mixing sulfonated polystyrene foaming agent into the geopolymer concrete; the main components and the mass ratio of the fiber waterproof mortar layer are cement 100-120 parts, sand 300-340 parts, water 50-66 parts and glass fiber 2-4 parts; the thickness of the fiber waterproof mortar layer is 3-5 mm; and the length of the glass fiber is 2-3 mm.

[0011] Optionally, the deep beam top is provided with a water baffle and a waterproof mortar layer, and both ends are provided with positioning and connecting protrusions; the deep beam is a cuboid with a size of 3.0m-4.0m in length, 0.2m-0.3m in width and 1m-1.5m in height; the cross section of the water baffle is a square with a size of 0.1m-0.2m in length and 0.1m-0.2m in width.

[0012] Optionally, the positioning pile is a square pile with a water baffle at the pile end and positioning and connecting grooves opened on four sides of the positioning pile; the cross section of the positioning pile is a square with a side length of 0.2m-0.3m, and the pile length of the positioning pile is 3m-4m; the size of the water baffle is 0.1m-0.2m in length, 0.1m-0.2m in width and 0.1m-0.2m in height.

[0013] Optionally, after the positioning pile is installed, the deep beam is fixed by inserting the positioning and connecting protrusions into the positioning and connecting grooves.

[0014] Optionally, the flexible pressure-relieving and drag-reducing layer is formed by spraying a W-OH solution with a concentration of 6%-10%, and the unit area spraying amount G is calculated by the following formula:

[0015] P=Alnω+B (1)

[0016] T1=Etε (2)

[0017] E=1598.7α-2571.5 (3)

[0018] T1 L≧PS (4)

[0019] G=1000βt (5)

[0020] In the formula, P is the swelling stress of red sandstone at different water contents ω; A and B are regression coefficients, the value range of A is 55-65 and the value range of B is 330-400 determined by experiments; ln is a logarithmic function; T1 is the tensile stress when the elastic deformation of the flexible pressure-relieving and drag-reducing layer is t; E is the elastic modulus of the flexible pressure-relieving and drag-reducing layer; t is the thickness of the flexible pressure-relieving and drag-reducing layer; ε is the strain of the flexible pressure-relieving and drag-reducing layer; α is the concentration of the W-OH solution; L is the width of the flexible pressure-relieving and drag-reducing layer; S is the surface area of the red sandstone; G is the unit area spraying amount of the W-OH solution; and β is the solidification volume coefficient of the W-OH solution.

[0021] Optionally, the flexible pressure-relieving and drag-reducing layer is formed after the construction of the deep frame beam is completed, and the flexible pressure-relieving and drag-reducing layer is formed on the fiber waterproof mortar layer and the deep frame beam according to the design and calculation requirements, and the edges of the flexible pressure-relieving and drag-reducing layer are formed on the upper surface of the deep beam and spliced with the waterproof mortar layer.

[0022] Optionally, the slope toe retaining wall comprises a retaining wall body and a pressure relief heel, the retaining wall body is uniformly provided with water outlet grooves at the top, the deep beam is connected with the retaining wall body at the end, the deep beam intersects with the water outlet grooves at the slope bottom, the pressure relief heel is embedded in the excavated exposed slope toe, and the retaining wall body and the pressure relief heel are both provided with ladder type anti-skid teeth at the bottom.

[0023] The slope toe retaining wall is poured with the waste tire steel fiber UHPC concrete, and is divided into a compression zone, a transition zone and a tension zone according to the stress characteristics; the steel fiber content of the compression zone is 1%, the steel fiber content of the transition zone is 3%, and the steel fiber content of the tension zone is 5%; the cross-sectional size of the retaining wall body is 0.6m-1.0m in width and 1.0m-1.5m in height; the cross section of the pressure relief heel is a right triangle, the size is 0.5m-1.0m in width and 0-0.5m in height, and the length is the same as the retaining wall body; the inner cross section of the water outlet groove is a circle, the radius is 5cm-10cm, and the groove slope is 2%-5%; the cross section of the ladder type anti-skid tooth is a rectangle, the length is the same as the slope toe retaining wall, the size is 0.1m-0.15m in width and 0.4m-0.1m in height, and the height decreases linearly from the outside of the slope to the inside of the slope body; the waterproof root-resistant layer adopts a high-density polyethylene self-adhesive membrane waterproof roll material, and the thickness is 1.2-1.5mm; the planting soil layer is 0.4m-0.6m thick; the W-OH anti-scouring layer is formed by spraying a W-OH solution with a concentration of 3%-4%, and the spraying amount is 1.2L / m 2 -1.4L / m 2 ; the W-OH waterproof and pressure-allowing and resistance-reducing layer is located below the fiber waterproof mortar layer; the W-OH waterproof and pressure-allowing and resistance-reducing layer is formed by spraying a W-OH solution with a concentration of 6%-8%, and the spraying amount is 1.5L / m 2 -1.8L / m 2 .

[0024] The application also provides a construction method of the red sandstone cutting slope ecological protection structure.

[0025] Step S1, slope trimming: according to the design drawing, the slope is excavated and trimmed to the designed slope;

[0026] Step S2, slope toe retaining wall construction: excavate the slope toe retaining wall and the drainage ditch earthwork, and erect the slope toe retaining wall formwork, then pour the waste tire steel fiber UHPC concrete to form the slope toe retaining wall after the formwork erection is completed.

[0027] Step S3, deep frame beam is applied: taking the water outlet groove as the base point, the position of the deep frame beam is lofted and the position of the positioning pile is marked by using the GPS instrument, the excavator digs the soil to dig the deep beam groove, then the positioning pile is punched into the design specified position and the installation direction is adjusted, the deep beam is hoisted between the two positioning piles, and the positioning and connecting groove and the positioning and connecting convex block are aligned and positioned and connected, the deep beam is connected and fixed with the positioning pile;

[0028] Step S4, the fiber waterproof mortar layer, the flexible pressure reduction layer and the waterproof root prevention layer are applied: the fiber waterproof mortar layer is sprayed on the excavated bare slope, after the waterproof mortar layer reaches the design strength, the calculated amount of W-OH solution is sprayed on the slope surface and the deep beam, so that the flexible pressure reduction layer with a certain thickness is formed on the slope surface; after the flexible pressure reduction layer is formed, the waterproof root prevention layer is laid;

[0029] Step S5, the planting soil layer is filled: the planting soil with sufficient fertility is selected, and then the planting soil is filled into the rhombus framework formed by the deep beam baffle;

[0030] Step S6, the W-OH anti-scouring layer is sprayed: the W-OH solution with a concentration of 3% to 4% is prepared, low-temperature pure water with a temperature of 3 to 4 degrees Celsius is used during the preparation, and then the W-OH solution is sprayed on the surface of the planting soil;

[0031] Step S7, the water interception ditch and the drainage ditch are applied: the water interception ditch and the drainage ditch are excavated, the W-OH solution with a concentration of 6% to 8% is prepared, low-temperature pure water with a temperature of 3 to 4 degrees Celsius is used during the preparation, and then the W-OH solution is sprayed on the surface of the water interception ditch and the drainage ditch, and then the fiber waterproof mortar layer is constructed on the W-OH waterproof and pressure reduction layer.

[0032] Compared with the prior art, the present application has the following beneficial effects:

[0033] (1) Application of low-carbon and environment-friendly materials: geopolymer is used as a cementing material instead of cement, the raw materials of geopolymer are mainly industrial solid wastes, and calcination is not required, and geopolymer has the advantages of fast hardening, early setting, high strength, strong corrosion resistance, good impermeability and long service life of structure; steel fiber extracted from waste tires is used to prepare low-cost steel fiber geopolymer concrete, which avoids the use of steel bars and effectively reduces the operation and maintenance cost in the whole life cycle; at the same time, steel fiber extracted from waste tires is used to prepare low-cost UHPC.

[0034] (2) Pre-assembled construction process, prevent rock mass deterioration: the deep frame beam and the positioning pile adopt the pre-assembled construction process, which avoids formwork on the slope, greatly improves the construction efficiency, avoids disturbance to the rock mass and water use on site as much as possible, reduces the contact time of the exposed red sandstone with air and rainwater, and effectively prevents the deterioration of the rock mass.

[0035] (3) drainage path is short, waterproof effect is good: the deep frame beam is arranged into a rhombus and the long diagonal is perpendicular to the slope foot, which is beneficial to the rapid convergence and drainage of rainwater, avoids the problems of poor drainage and long drainage path of the traditional square frame beam; by setting a root resistance layer, a high-concentration modified hydrophilic polyurethane flexible pressure-relieving and resistance-reducing layer, a seepage-proof coating and a series of seepage-proof and erosion-prevention measures, the seepage of rainwater and the disintegration and degradation of red sandstone are effectively avoided, and the stability of the slope is ensured.

[0036] (4) deep frame beam supporting mode, reducing the influence of construction on the slope body: avoiding the supporting mode of anchor rod or anchor cable, effectively reducing the disturbance of slope construction on deep rock mass and the seepage of rainwater, embedding the protective beam into the rock slope by setting a deep frame beam baffle, and connecting with the slope bottom retaining wall, effectively improving the supporting effect of the deep beam baffle, solving a series of problems such as the easy emptying of the bottom of the traditional frame beam plate caused by water erosion and the failure of protection.

[0037] (5) setting a flexible pressure-relieving and resistance-reducing layer, having pressure-relieving and resistance-reducing effect: in view of the swelling and frost heaving of red sandstone after absorbing water, a layer of high-concentration modified hydrophilic polyurethane flexible pressure-relieving and resistance-reducing layer is set on the surface of the slope and the bottom of the deep frame beam, the thickness of the flexible pressure-relieving and resistance-reducing layer is determined by calculating the swelling amount of red sandstone, when the red sandstone swells, the pressure-relieving and resistance-reducing function can be realized by compressing the modified hydrophilic polyurethane flexible layer, preventing the damage of the supporting structure.

[0038] (6) the planting soil has water-fixing effect, and the ecological protection effect is good: the low-density modified hydrophilic polyurethane (W-OH) combined with the bottom seepage-proof layer makes the planting soil have the functions of water permeability, erosion prevention and water fixation, which can improve the greening effect of ecological protection of the slope, avoid long-term high-frequency artificial watering, greatly reduce the maintenance cost in the later period, and the degradation product of W-OH has no pollution to the environment, which has high popularization. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0040] Figure 1 The overall structure schematic diagram of the red sandstone cutting slope ecological protection structure provided by the present application is shown in the figure.

[0041] Figure 2 The deep beam installation structure schematic diagram provided by the present application is shown in the figure.

[0042] Figure 3 The deep beam and positioning pile installation effect schematic diagram provided by the present application is shown in the figure.

[0043] Figure 4 The deep beam and positioning pile assembly structure diagram provided by the present application;

[0044] Figure 5 The deep beam structure diagram provided by the present application;

[0045] Figure 6 The positioning pile structure diagram provided by the present application;

[0046] Figure 7 The toe retaining wall section diagram provided by the present application

[0047] Figure 8 The toe retaining wall stress partition diagram and material configuration diagram provided by the present application.

[0048] 1, excavation exposed slope; 2, deep frame beam; 21, deep beam; 211, water retaining plate; 212, positioning and connecting protrusion; 213, waterproof mortar layer; 22, foam geopolymer concrete; 23, positioning pile; 231, water retaining block; 232, positioning and connecting groove; 3, toe retaining wall; 31, retaining wall body; 311, water outlet groove; 312, ladder type anti-skid tooth; 32, pressure relief heel; 33, pressure receiving area; 34, transition area; 35, tension area; 4, fiber waterproof mortar layer; 5, flexible pressure relief and resistance reduction layer; 6, waterproof and root resistance layer; 7, planting soil layer; 8, W-OH scour prevention layer; 9, water interception ditch; 91, drainage ditch; 92, W-OH waterproof and pressure relief and resistance reduction layer; 10, green plants; 11, rainwater convergence direction. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0050] Please refer to Figures 1 to 8 The present application provides a red sandstone cutting slope ecological protection structure, which comprises an excavation exposed slope 1, a deep frame beam 2, a positioning pile 23, a toe retaining wall 3, a fiber waterproof mortar layer 4, a flexible pressure relief and resistance reduction layer 5, a waterproof and root resistance layer 6, a planting soil layer 7, a W-OH scour prevention layer 8, a water interception ditch 9, and a drainage ditch 91. The deep frame beam 2 is embedded on the excavation exposed slope 1 through the positioning pile 23. The toe retaining wall 3 is arranged at the bottom of the excavation exposed slope 1. The fiber waterproof mortar layer 4, the flexible pressure relief and resistance reduction layer 5, the waterproof and root resistance layer 6, the planting soil layer 7, and the W-OH scour prevention layer 8 are sequentially arranged on the slope surface of the excavation exposed slope 1. The water interception ditch 9 and the drainage ditch 91 are arranged at the top and the bottom of the excavation exposed slope 1, respectively.

[0051] The excavation slope of the excavated bare slope 1 is 1:1.5.

[0052] In further detail Figures 2 to 4 As shown, the deep frame beam 2 comprises deep beams 21, foam geopolymer concrete 22 and positioning piles 23, the positioning piles 23 are in a rhombic matrix and are inserted into the excavated bare slope 1, the deep beams 21 are arranged between two adjacent positioning piles 23 and are spliced with the side of the positioning piles 23 at the end, and the foam geopolymer concrete 22 fills the cavity between the deep beams 21 and the soil of the excavated bare slope 1.

[0053] The deep frame beam 2 is prefabricated from geopolymer concrete with a strength of 40-60 MPa, and the geopolymer concrete comprises 180-200 parts of slag, 50-80 parts of fly ash, 25-35 parts of silica fume, 40-60 parts of solid sodium hydroxide, 900-920 parts of gravel, 450-500 parts of medium sand, 85-100 parts of mixing water and 20-30 parts of waste tire steel fiber. The waste tire steel fiber is made of steel fiber recovered from waste tires, and the length is 8-11 mm.

[0054] The foam geopolymer concrete 22 and the geopolymer concrete in the deep frame beam 2 have the same proportion, and a sulfonated polystyrene foaming agent is added to the geopolymer concrete to make the foam geopolymer concrete 22; the main components and the mass ratio of the fiber waterproof mortar layer 4 are cement 100-120 parts, sand 300-340 parts, water 50-66 parts, and glass fiber 2-4 parts; the thickness of the fiber waterproof mortar layer 4 is 3-5 mm; and the length of the glass fiber is 2-3 mm.

[0055] In further detail Figure 4 And Figure 5 As shown, the deep beam 21 is provided with a water baffle 211 and a waterproof mortar layer 213 at the top, and positioning and connecting lugs 212 are arranged at both ends.

[0056] The deep beam 21 is a cuboid with a size of 3.0-4.0 m in length, 0.2-0.3 m in width and 1-1.5 m in height; and the cross section of the water baffle 211 is a square with a size of 0.1-0.2 m in length and 0.1-0.2 m in width.

[0057] In further detail Figure 6 As shown, the positioning pile 23 is a square pile, and a water blocking block 231 and a positioning and connecting groove 232 are arranged at the end of the pile and on the four sides of the positioning pile 23, respectively; the cross section of the positioning pile 23 is a square with a side length of 0.2-0.3 m, and the length of the pile is 3-4 m; and the size of the water blocking block 231 is 0.1-0.2 m in length, 0.1-0.2 m in width and 0.1-0.2 m in height.

[0058] After the positioning pile 23 is installed, the deep beam 21 is fixed by inserting the positioning and connecting protrusion 212 into the positioning and connecting groove 232, so that the direction of rainwater convergence can be as follows: Figure 3 As shown in reference number 11.

[0059] Further specific combinations Figure 7 As shown, the retaining wall 3 at the toe of the slope includes a retaining wall body 31 and a pressure relief heel 32. The top of the retaining wall body 31 is evenly provided with a water outlet channel 311. The end of the deep beam 21 is connected to the retaining wall body 31. The deep beam 21 intersects with the water outlet channel 311 at the bottom of the slope. The pressure relief heel 32 is embedded in the toe of the excavated exposed slope 1. The bottom of both the retaining wall body 31 and the pressure relief heel 32 is provided with stepped anti-slip teeth 312.

[0060] Further specific combinations Figure 8 As shown, the slope toe retaining wall 3 is made of waste tire steel fiber UHPC concrete and is divided into compression zone 33, transition zone 34 and tension zone 35 according to its stress characteristics; the steel fiber content of the compression zone 33 is 1%, the steel fiber content of the transition zone 34 is 3%, and the steel fiber content of the tension zone 35 is 5%.

[0061] The retaining wall 31 has a cross-sectional dimension of 0.6m to 1.0m wide and 1.0m to 1.5m high; the pressure relief heel 32 has a right-angled triangular cross-section with a width of 0.5m to 1.0m and a height of 0m to 0.5m, and the same length as the retaining wall 31; the water outlet trough 311 has a circular inner cross-section with a radius of 5cm to 10cm and a slope of 2% to 5%; the stepped anti-slip teeth 312 have a rectangular cross-section with the same length as the slope toe retaining wall 3, and a width of 0.1m to 0.15m and a height of 0.4m to 0.1m, with the height decreasing linearly from the outside of the slope to the inside of the slope.

[0062] The waterproof and root-barrier layer 6 is made of high-density polyethylene self-adhesive waterproof membrane with a thickness of 1.2–1.5 mm; the planting soil layer 7 is 0.4 m–0.6 m thick; the W-OH erosion-resistant layer 8 is formed by spraying a 3%–4% W-OH solution at a spraying rate of 1.2 L / m. 2 ~1.4L / m 2 .

[0063] The flexible pressure-reducing and drag-reducing layer 5 is formed by spraying a 6% to 10% W-OH solution, and its spraying amount G per unit area is calculated using the following formula:

[0064] P=AInω+B (1)

[0065] T1=Etε (2)

[0066] E = 1598.7α - 2571.5 (3)

[0067] T1 L≧PS(4)

[0068] G=1000βt (5)

[0069] In the formula, P is the swelling stress (kPa) of red sandstone at different water contents ω; A and B are regression coefficients, the value range of A is 55-65 and the value range of B is 330-400 determined by experiment; In is a logarithmic function; T1 is the tensile stress (kN / m) of the flexible pressure-relief and drag-reduction layer when it is elastically deformed; E is the elastic modulus (kPa) of the flexible pressure-relief and drag-reduction layer; t is the thickness (m) of the flexible pressure-relief and drag-reduction layer; ε is the strain (%) of the flexible pressure-relief and drag-reduction layer (W-OH film); α is the concentration (mass ratio) of the W-OH solution; L is the width (m) of the flexible pressure-relief and drag-reduction layer; S is the surface area (m2) of the red sandstone; G is the W-OH solution spraying amount per unit area (L / m2); and β is the W-OH solution solidification volume coefficient (0.95). 2 2

[0070] In the formula, P is the swelling stress (kPa) of red sandstone at different water contents ω; A and B are regression coefficients, the value range of A is 55-65 and the value range of B is 330-400 determined by experiment; In is a logarithmic function; T1 is the tensile stress (kN / m) of the flexible pressure-relief and drag-reduction layer when it is elastically deformed; E is the elastic modulus (kPa) of the flexible pressure-relief and drag-reduction layer; t is the thickness (m) of the flexible pressure-relief and drag-reduction layer; ε is the strain (%) of the flexible pressure-relief and drag-reduction layer (W-OH film); α is the concentration (mass ratio) of the W-OH solution; L is the width (m) of the flexible pressure-relief and drag-reduction layer; S is the surface area (m2) of the red sandstone; G is the W-OH solution spraying amount per unit area (L / m2); and β is the W-OH solution solidification volume coefficient (0.95).

[0071] Table 1 E and α values of the W-OH solution solidified at different concentrations

[0072]

[0073] It should be further explained that formula (1) is a calculation formula of the swelling force P of the red sandstone at different water contents ω (the maximum water content of the red sandstone is 4%); formula (2) is a calculation formula of the tensile stress T1 of the flexible pressure-relief and drag-reduction layer when it is elastically deformed at different strains ε (the maximum strain is 2%); formula (3) is a calculation formula of the elastic modulus E of the flexible pressure-relief and drag-reduction layer; formula (4) is that the tensile force T1 L of the flexible pressure-relief and drag-reduction layer when it is elastically deformed should be greater than the swelling force PS of the red sandstone; and formula (5) is the W-OH solution spraying amount per unit area G.

[0074] The tensile force T1 L of the flexible pressure-relief and drag-reduction layer 5 when it is elastically deformed should be greater than the swelling force PS of the red sandstone at different water contents ω; and the calculation process is as follows:

[0075] Step one: obtain the coefficients 65 and 350 in formula (1) by indoor test;

[0076] Step two: calculate the tensile stress T1 of the flexible pressure-relief and drag-reduction layer when it is elastically deformed at unit width by formula (2), and obtain the elastic modulus E of the flexible pressure-relief and drag-reduction layer by formula (3);

[0077] ​​Step three: the results P, T1, E obtained from formula (1), formula (2) and formula (3) are substituted into formula (4) to solve the minimum thickness t of the flexible pressure-relief and drag-reduction layer 5, t = 0.0189 m;

[0078] Step four: the t obtained in step three is substituted into formula (5) to obtain the minimum spraying amount of the W-OH solution per unit area, which is 17.955 L.

[0079] Further, the flexible pressure-relief and drag-reduction layer 5 is constructed after the construction of the deep frame beam 2 is completed, and the flexible pressure-relief and drag-reduction layer 5 is sprayed and formed on the fiber waterproof mortar layer 4 and the deep frame beam 2 according to the design and calculation requirements, and the edge of the flexible pressure-relief and drag-reduction layer 5 is constructed to the upper surface of the deep beam 21 and spliced with the waterproof mortar layer 213.

[0080] The planting soil layer 7 is provided with green plants 10.

[0081] The W-OH waterproof and pressure-relief and drag-reduction layer 92 is located at the lower part of the fiber waterproof mortar layer 4, and the W-OH waterproof and pressure-relief and drag-reduction layer 92 is sprayed by using W-OH with a concentration of 6% to 8%, and the spraying amount is 1.5 L / m 2 ~ 1.8 L / m 2 .

[0082] The application also provides a construction method of the red sandstone cutting slope ecological protection structure.

[0083] Step S1, slope trimming: according to the design drawing, the slope is excavated and trimmed to the design slope;

[0084] Step S2, construction of slope toe retaining wall: excavate the slope toe retaining wall and drainage ditch earthwork, erect the slope toe retaining wall formwork, pour the waste tire steel fiber UHPC concrete to form the slope toe retaining wall after the completion of the formwork erection;

[0085] Step S3, construction of deep frame beam: take the water outlet groove as the base point, use the GPS instrument to loft the position of the deep frame beam and mark the position of the positioning pile, excavate the deep beam groove by the excavator, then punch the positioning pile into the design specified position and adjust the installation direction, hoist the deep beam between the two positioning piles, align and position the connecting groove and the positioning and connecting protrusion, and connect and fix the deep beam and the positioning pile;

[0086] Step S4, construction of the fiber waterproof mortar layer, the flexible pressure-relief and drag-reduction layer and the waterproof root-resistant layer: spray the fiber waterproof mortar layer on the excavated bare slope, after the waterproof mortar layer reaches the design strength, spray the quantitative W-OH solution on the slope surface and the deep beam according to the calculation result, so that the slope surface forms the flexible pressure-relief and drag-reduction layer with a certain thickness; after the flexible pressure-relief and drag-reduction layer is formed, the waterproof root-resistant layer is laid;

[0087] Step S5, filling the planting soil layer: selecting the planting soil with sufficient fertility, and then filling it into the rhombus framework formed by the deep beam baffle;

[0088] Step S6, spraying the W-OH anti-scouring layer: preparing the W-OH solution with a concentration of 3% to 4%, using low-temperature pure water with a temperature of 3°C to 4°C during preparation, and then spraying it onto the surface of the planting soil;

[0089] Step S7, constructing the water interception ditch and the drainage ditch: excavating the water interception ditch and the drainage ditch, preparing the W-OH solution with a concentration of 6% to 8%, using low-temperature pure water with a temperature of 3°C to 4°C during preparation, and then spraying it onto the surface of the water interception ditch and the drainage ditch, and then constructing the fiber waterproof mortar layer on the W-OH waterproof and pressure-reducing and drag-reducing layer.

[0090] It is to be understood that the terminology "including", "comprising", or any other variation thereof, is intended to cover a non-exclusive inclusion such that processes, methods, articles, or apparatuses that comprise a list of elements are not to be construed as being limited to only those elements specifically named. Other elements can be added without departing from the scope of the present application.

[0091] Furthermore, it is to be understood that the scope of the present application is not limited to the order of execution of the functions illustrated or discussed, but can also include execution of the functions in a substantially simultaneous manner or in the reverse order, for example, the described methods can be executed in an order different from that described, and various steps can be added, omitted, or combined. In addition, features described with reference to certain examples can be combined in other examples.

[0092] The above describes the embodiments of the present application, but the present application is not limited to the above-described specific embodiments, and the above-described specific embodiments are merely illustrative, rather than limiting, and those skilled in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, which are all within the protection of the present application.

Claims

1. A red sandstone cutting slope ecological protection structure, characterized in that, It includes excavated bare slope (1), deep frame beam (2), positioning pile (23), slope foot retaining wall (3), fiber waterproof mortar layer (4), flexible pressure-reducing resistance layer (5), waterproof root-resistant layer (6), planting soil layer (7), W-OH scour prevention layer (8), water interception ditch (9) and drainage ditch (91); the deep frame beam (2) is embedded on the excavated bare slope (1) through the positioning pile (23), the deep frame beam (2) includes deep beam (21), filling foam geopolymer concrete (22) and positioning pile (23), the positioning pile (23) is in a diamond matrix and is inserted into the excavated bare slope (1), the deep beam (21) is arranged between the adjacent two positioning piles (23) and is spliced with the side surface of the positioning pile (23) at the end, the filling foam geopolymer concrete (22) is filled in the cavity between the deep beam (21) and the soil body of the excavated bare slope (1); the slope foot retaining wall (3) is arranged at the bottom of the excavated bare slope (1); the fiber waterproof mortar layer (4), the flexible pressure-reducing resistance layer (5), the waterproof root-resistant layer (6), the planting soil layer (7) and the W-OH scour prevention layer (8) are sequentially arranged on the slope surface of the excavated bare slope (1); the water interception ditch (9) and the drainage ditch (91) are respectively arranged at the top and the bottom of the excavated bare slope (1); the flexible pressure-reducing resistance layer (5) is formed by spraying W-OH solution with a concentration of 6% to 10%, and the unit area spraying amount G It is obtained by the following formula: （1） （2） E =1598.7 α -2571.5 （3） T 1 L ≧ PS （4） G= 1000 βt （5） In the formula, P for different moisture contents ω The swelling stress of lower red sandstone; A and B are regression coefficients, and the value range of A is 55-65 and the value range of B is 330-400 determined by experiment; is a logarithmic function; T 1 is the tensile stress when the flexible yielding and drag-reducing layer of unit width is elastically deformed; E is the elastic modulus of the flexible yielding and drag-reducing layer; t is the thickness of the flexible yielding and drag-reducing layer; ε is the strain of the flexible yielding and drag-reducing layer; α is the concentration of W-OH solution; L is the width of the flexible yielding and drag-reducing layer; S is the surface area of red sandstone; G is the unit area W-OH solution spraying amount; β is the W-OH solution solidification volume coefficient; The waterproof root-resistant layer (6) adopts a high-density polyethylene self-adhesive waterproof roll material.

2. The ecological protection structure for red sandstone cutting slope according to claim 1, characterized in that, The deep frame beam (2) is prefabricated from geopolymer concrete with a strength of 40-60 MPa, and the geopolymer concrete comprises 180-200 parts of slag, 50-80 parts of fly ash, 25-35 parts of silica fume, 40-60 parts of solid sodium hydroxide, 900-920 parts of gravel, 450-500 parts of medium sand, 85-100 parts of mixing water, and 20-30 parts of waste tire steel fiber.

3. The ecological protection structure for red sandstone cutting slope according to claim 2, characterized in that, The filling foam geopolymer concrete (22) has the same proportion as the geopolymer concrete in the deep frame beam (2) and is made by mixing sulfonated polystyrene foaming agent into the geopolymer concrete; the main components and the mass ratio of the fiber waterproof mortar layer (4) are cement 100-120 parts, sand 300-340 parts, water 50-66 parts, and glass fiber 2-4 parts; the thickness of the fiber waterproof mortar layer (4) is 3-5 mm; and the length of the glass fiber is 2-3 mm.

4. The ecological protection structure for red sandstone cutting slope according to claim 1, characterized in that, The deep beam (21) is provided with a water baffle (211) and a waterproof mortar layer (213) on the top and positioning and connecting lugs (212) at both ends; the deep beam (21) is a cuboid with a size of 3.0-4.0 m in length, 0.2-0.3 m in width, and 1-1.5 m in height; and the cross section of the water baffle (211) is a square with a size of 0.1-0.2 m in length and 0.1-0.2 m in width.

5. The ecological protection structure for red sandstone cutting slope according to claim 4, characterized in that, The positioning pile (23) is a square pile provided with a water retaining block (231) at the pile end and positioning and connecting grooves (232) opened on four sides of the positioning pile (23); the cross section of the positioning pile (23) is a square with a side length of 0.2-0.3 m, the pile length of the positioning pile is 3-4 m, and the size of the water retaining block (231) is 0.1-0.2 m in length, 0.1-0.2 m in width, and 0.1-0.2 m in height.

6. The ecological protection structure for red sandstone cutting slope according to claim 5, characterized in that, After the positioning pile (23) is installed, the deep beam (21) is fixed by inserting the positioning and connecting lugs (212) into the positioning and connecting grooves (232).

7. The ecological protection structure of red sandstone cutting slope according to claim 6, characterized in that, The flexible pressure-relieving and resistance-reducing layer (5) is sprayed and formed on the fiber waterproof mortar layer (4) and the deep frame beam (2) according to the design and calculation requirements after the deep frame beam (2) is constructed; and the edges of the flexible pressure-relieving and resistance-reducing layer (5) are applied to the upper surface of the deep beam (21) and spliced with the waterproof mortar layer (213).

8. The ecological protection structure of red sandstone cutting slope according to claim 1, characterized in that, The slope toe retaining wall (3) comprises a retaining wall body (31) and a pressure-relieving heel (32); the retaining wall body (31) is uniformly provided with water outlet grooves (311) on the top; the deep beam (21) is connected with the retaining wall body (31) at the end, and the deep beam (21) intersects with the water outlet grooves (311) at the slope bottom; the pressure-relieving heel (32) is embedded into the slope toe of the excavated bare slope (1); and the retaining wall body (31) and the bottom of the pressure-relieving heel (32) are both provided with stepped anti-skid teeth (312). The toe retaining wall (3) is poured with waste tire steel fiber UHPC concrete, and is divided into compression zone (33), transition zone (34) and tension zone (35) according to its stress characteristics; the steel fiber content of the compression zone (33) is 1%, the steel fiber content of the transition zone (34) is 3%, and the steel fiber content of the tension zone (35) is 5%; the cross-sectional size of the retaining wall body (31) is 0.6m~1.0m wide x 1.0m~1.5m high; the pressure-reducing heel (32) is a right-angled triangle, with a size of 0.5m~1.0m wide x 0m~0.5m high, and the length is the same as the retaining wall body (31); the water outlet groove (311) is circular in cross-section, with a radius of 5cm~10cm, and the groove slope is 2%~5%; the stepped anti-skid tooth (312) is rectangular in cross-section, with a length the same as the toe retaining wall (3), a size of 0.1m~0.15m wide x 0.4m~0.1m high, and the height decreases linearly from the outside of the slope to the inside of the slope; the waterproof root-resistant layer (6) is 1.2~1.5mm thick; the planting soil layer (7) is 0.4m~0.6m thick; the W-OH anti-scour layer (8) is formed by spraying a W-OH solution with a concentration of 3%~4%, with a spraying amount of 1.2L / m 2 ~1.4L / m 2 ; the water interception ditch (9) and the drainage ditch (91) are provided with a W-OH waterproof and pressure-allowing and resistance-reducing layer (92) and a fiber waterproof mortar layer (4); the W-OH waterproof and pressure-allowing and resistance-reducing layer (92) is located below the fiber waterproof mortar layer (4); the W-OH waterproof and pressure-allowing and resistance-reducing layer (92) is formed by spraying a W-OH solution with a concentration of 6%~8%, with a spraying amount of 1.5L / m 2 ~1.8L / m 2 .

9. The construction method of the red sandstone cutting slope ecological protection structure according to any one of claims 1-8, characterized in that, The method comprises the following steps: Step S1, slope trimming: according to the design drawing, the slope is excavated and trimmed to the designed slope; Step S2, slope toe retaining wall is constructed: excavate the slope toe retaining wall and drainage ditch earthwork and erect the slope toe retaining wall formwork, after the formwork is erected, the waste tire steel fiber UHPC concrete is poured to form the slope toe retaining wall; Step S3, deep frame beam is constructed: taking the water outlet groove as the base point, the position of the deep frame beam is lofted and the position of the positioning pile is marked by using the GPS instrument, the excavator excavates the deep beam groove, then the positioning pile is driven into the designed position and its installation direction is adjusted, the deep beam is hoisted between the two positioning piles, and the positioning and connecting groove and the positioning and connecting convex block are aligned and connected, the deep beam is connected and fixed with the positioning pile; Step S4, fiber waterproof mortar layer, flexible pressure-reducing and resistance-reducing layer and waterproof root-resistant layer are constructed: the fiber waterproof mortar layer is sprayed on the excavated bare slope, after the waterproof mortar layer reaches the designed strength, the calculated amount of W-OH solution is sprayed on the slope surface and the deep beam, so that the flexible pressure-reducing and resistance-reducing layer with a certain thickness is formed on the slope surface; After the flexible pressure-reducing and resistance-reducing layer is formed, the waterproof root-resistant layer is laid; Step S5, planting soil layer is filled: the planting soil with sufficient fertility is selected, then it is filled into the rhombus framework formed by the deep beam baffle; Step S6, W-OH anti-scouring layer is sprayed: the W-OH solution with a concentration of 3%~4% is prepared, when the W-OH solution is prepared, the low-temperature pure water with a temperature of 3℃~4℃ is used, then the W-OH solution is sprayed on the surface of the planting soil; Step S7, water interception ditch and drainage ditch are constructed: the water interception ditch and the drainage ditch are excavated, the W-OH solution with a concentration of 6%~8% is prepared, when the W-OH solution is prepared, the low-temperature pure water with a temperature of 3℃~4℃ is used, then the W-OH solution is sprayed on the surface of the water interception ditch and the drainage ditch, then the fiber waterproof mortar layer is constructed on the W-OH waterproof and pressure-reducing and resistance-reducing layer.

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