An integrated outlet structure of a tourist trail and a water cascade and its design method

Abstract

The present invention discloses a combined structure and design method of a tourist footpath and a stepped waterfall outlet, which includes a straight wall closely arranged at the outlet of a culvert; a plurality of platform sections are arranged at intervals along the slope direction from top to bottom under the straight wall. The upper platform section is closely arranged with the straight wall and forms an enclosed space therewith, and the lower platform section is set as the water outlet; a stepped waterfall section is connected between two adjacent platform sections. The top elevations of the platform sections and the stepped waterfall section are flush with the slope surface; both the platform sections and the stepped waterfall section include a cover plate, side walls, a bottom plate and a cushion layer. The bottom plate is poured on the cushion layer, and the side walls are poured and separated on both sides of the bottom plate and jointly form a water passage space with the bottom plate. The cover plate is placed on the side walls on both sides; the cover plate of the platform section can form a rest platform for pedestrians; the cover plates of the stepped waterfall section are arranged in a graded manner with gradients along the slope direction on the side walls, forming a stepped footpath for pedestrians to climb. It saves the slope protection space and the viewing platform space and protects the integrity of the engineering landscape.

Description

Technical Field

[0001] The present invention relates to the field of mountain road reconstruction projects, and particularly to an integrated outlet structure and design method for a tourist footpath and a drop water. Background Art

[0002] In recent years, the progress of the treatment of the waterfront ecological shoreline has been accelerated everywhere, and a large number of waterfront projects such as riverside, lakeside, and hydrophilic have emerged. Such projects often play multiple roles such as urban roads, landscaping, reservoir bank renovation, drainage and flood control, and levee projects. Therefore, compared with conventional independent professional projects, higher requirements are put forward for the details of the project and the cooperation between specialties. The waterfront projects with the functions of recreation and viewing need to set up multiple tourist ladder footpaths so that tourists can descend from the road at the top of the project to the riverside viewing platform. Whether it is possible to combine the engineering functional structure with the pedestrian footpath to achieve the effect of multi-purpose use of one thing, economy and beauty is a very worthy research issue.

[0003] In the waterfront project, the super-long drainage culvert that penetrates the dike, the road, combines the revetment and the levee is a typical complex engineering node. Due to the large number of engineering slope levels, the height difference reaches dozens of meters, and the length is often more than one hundred meters, so it cannot be designed according to the conventional culvert. In the culvert design specification, it is stipulated that the longitudinal slope of the main part of the culvert should not be greater than 3%. However, the slope ratios of the engineering slopes are mostly 40-67%, which are much larger than the longitudinal slope allowed by the specification. Therefore, structural measures need to be taken to overcome the height difference between the inlet and the outlet. The existing solutions include two types. One is a deeply buried culvert with multiple drop wells, and the other is a shallowly buried culvert with an ultra-long outlet.

[0004] The first solution is to set multiple drop wells between the main structures of the culvert. Each drop well drops the water level by 3-6 meters until it connects to the outlet at the target elevation. Since the deeply buried culvert and the drop wells have a large amount of steel reinforcement and cannot be prefabricated, the cost is high and the construction period is long; the main structure of the culvert is deeply buried underground and has a large length, and it needs to be maintained by going down the inspection well, and the maintenance is relatively inconvenient.

[0005] The second solution relies on the outlet to overcome the height difference. Since the specification does not limit the longitudinal slope of the outlet, a long ramp with the same longitudinal slope as the slope ratio of the slope can be used to conduct water, and a stilling basin is set at the slope platform. This solution is relatively cheaper than the first solution, but it needs to occupy a large amount of slope protection and viewing platform space, dividing the complete project landscape into multiple areas. And because it is an open design, there is a safety risk that tourists may fall in by mistake, so additional guardrails need to be installed.

[0006] In summary, there is an urgent need to propose a new design scheme for the culvert outlet to solve the deficiencies of the existing solutions. Further, combine the drainage structure with the pedestrian footpath to improve the functional value and economic benefits of the structure. Summary of the Invention

[0007] The present invention aims to overcome the shortcomings of the above-mentioned existing technical solutions, and proposes an integrated water outlet structure and design method for a tourist walkway and a waterfall, which combines a walkway and steps for pedestrians to go up and down with a water outlet structure. At the same time, the stepped bottom plate plays the role of waterfall energy dissipation. The technology is simple and easy to implement, and it does not take up space and reduces safety hazards, while shortening the construction period and reducing the project cost.

[0008] In order to solve the above technical problems, the present invention is implemented by the following technical solutions:

[0009] In the first aspect, the present invention provides an integrated water outlet structure for a tourist walkway and a waterfall, the structure is placed as a whole in the slope of a riverside project, and its bottom is placed on a compacted artificial foundation or a natural stable stratum; the structure comprises a straight wall, the straight wall is arranged close to the culvert outlet; a plurality of platform sections are arranged at intervals from top to bottom along the slope direction below the straight wall, the uppermost platform section is arranged close to the straight wall and forms a closed space therewith, and the lowermost platform section is arranged as a water outlet; two adjacent platform sections are arranged at intervals from top to bottom along the slope direction. There is a waterfall section connected between the sections, the platform section and the waterfall section both include a cover plate, side walls, a bottom plate and a cushion layer, the bottom plate is cast on the cushion layer, the side walls are cast separately on both sides of the bottom plate and together with the bottom plate constitute a water-passing space, the cover plate is placed on the side walls on both sides; the cover plates of the platform section and the waterfall section are both prefabricated cover plates, the cover plate of the platform section can form a recreational platform for pedestrians to rest; the cover plate of the waterfall section is arranged in a stepped shape to form a stepped walkway for pedestrians to climb.

[0010] Preferably, the bottom plates of the platform section and the drop section are respectively a flat bottom plate and a stepped bottom plate.

[0011] Furthermore, the platform section is divided into sections of 4-6m, and the drop section is divided into sections of 3 to 5 bottom plate steps. The sections serve as expansion joints and require waterproof structural treatment.

[0012] Furthermore, the ratio of the width to the height of each level of the bottom plate in the drop section should be adapted to the slope ratio of the side slope.

[0013] Furthermore, the side walls corresponding to each bottom step in the waterfall section are divided into two to three sections with different heights, and a cover plate is placed on the side wall at each height, thereby forming a stair walkway for pedestrians to climb.

[0014] Preferably, hanging bars are embedded on both sides of the top of the cover plate.

[0015] Preferably, the width of the cover plate is 30-50 cm, and the height of each step of the cover plate in the drop section is 10-20 cm.

[0016] Preferably, the bearing capacity of the filled soil foundation or natural stable formation should be not less than 100 Mpa.

[0017] Preferably, the top elevations of the platform section and the drop - water section are both flush with the slope surface.

[0018] In a second aspect, the present invention provides a design method for an integrated outlet structure of a tourist footpath and a drop - water, and the design method includes:

[0019] 1) Determine the positioning of the single - wing wall according to the position of the culvert outlet.

[0020] 2) Calculate the cross - sectional area of the outlet structure according to the culvert aperture, and it should satisfy that the minimum water - passing area of the outlet structure Qc / the effective water - passing area of the culvert Qj ≥ 1.2.

[0021] 3) The value range of the net water - passing height H0 of the outlet is preferably 1 m to 3 m, the net width B0 should not be less than the net width or diameter of the culvert, and Qc = H0 * B0; considering that the outlet structure also serves as a pedestrian footpath, B0 ≥ 3 m, thus preliminarily determining the net cross - sectional dimensions of the outlet structure.

[0022] 4) Determine the width - height values of the bottom steps and covers of the drop - water section according to the following limiting conditions:

[0023] 4.1) To make it comfortable for pedestrians to climb, 10 cm ≤ the step height Hg of the cover ≤ 20 cm.

[0024] 4.2) To make the outlet structure adapt to the slope ratio of the slope and blend into the overall project without being obtrusive, there should be the step height Hd: step width Bd = the step height Hg: step width Hg = the slope ratio of the slope where it is located 1:n.

[0025] 4.3) Every 2 to 3 steps correspond to one - level step, so Hd = 2 or 3 * Hg, Bd = 2 or 3 * Bg.

[0026] 4.4) Hd, Hg, Bd, and Bg are all preferably rounded to integers for easy construction.

[0027] 5) When the outlet structure passes through slopes with multiple different slope ratios, repeat step 4) according to their slope ratios 1:n1, 1:n2, 1:n3... to obtain 1 to 2 kinds of cover sizes that are as universal as possible. By unifying the cover sizes, adjust the sizes of the cast - in - place side walls and bottom steps, so as to facilitate the batch pre - casting of the covers.

[0028] 6) It is necessary to carry out force calculation and reinforcement checking calculation for the cover, and the specific steps are as follows:

[0029] 6.1) Refer to the crowd load calculation standard in the road and bridge design, and calculate the live load per linear meter of the slab q = crowd load.

[0030] 6.2) Calculate the dead load per meter g = the unit weight of the cover plate * the thickness of the cover plate using the design parameters of the cover plate cross-section determined in step 5).

[0031] 6.3) Conduct the internal force calculation of the cover plate

[0032] The extreme value of the bending moment Md under the ultimate limit state of bearing capacity = (0.15 * g + 0.175 * q) * B0 2

[0033] The extreme value of the shear force Vd = (0.6 * g + 0.7 * q) * B0

[0034] The extreme value of the bending moment Ms under the serviceability limit state = 0.125 * (g + q) * B0 2 ;

[0035] 6.4) Trial - match the steel bars for the cover plate in the direction perpendicular to the water flow, and check the height of the concrete compression zone, reinforcement ratio, flexural bearing capacity of the normal section, and crack width under the serviceability limit state according to the flexural members of reinforced concrete.

[0036] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0037] 1. Compared with the existing long water outlet scheme, the present invention combines the culvert water outlet structure with the tourist walkway, saving the slope protection space and the viewing platform space, and protecting the integrity of the engineering landscape; covering the open channel of the water outlet with a cover plate that also serves as a tourist walkway is both beautiful and practical, while eliminating the safety hazard of tourists accidentally falling in.

[0038] 2. Compared with the traditional deeply - buried culvert scheme (all structures need to be cast - in - place), the cover plate of the present invention adopts a precast structure, shortening the construction period by about one - third; with less reinforcement and a lower grade of steel bars; without the need to use a rock - filled foundation, so the project cost is greatly reduced in terms of engineering materials, construction period, and construction costs.

[0039] 3. The stairways and cover plates of the present invention are both modular, with a high degree of freedom, and can be easily modified to match different slope ratios and platform lengths, having a wide range of applications.

[0040] 4. The stepped shape of the present invention fits closely with the embankment / revetment structure, is not easy to slip, and at the same time, the design of continuous steps has a good effect of dissipating energy by hydraulic jump, especially suitable for projects in high - steep slopes and mountainous areas.

[0041] 5. The independent cover plate is convenient to disassemble and replace, and is easy to maintain later. Description of the Drawings

[0042] Figure 1 It is the structural central axis sectional view unfolded along the road and the cross - section of the reservoir bank in a certain example of the present invention.

[0043] Figure 2This is the structural cross-sectional view at the outlet section of the culvert in a certain example of the present invention.

[0044] Figure 3 It is Figure 2 the A-A sectional view (the sectional view of the single wing wall and the first platform section unfolded along the side wall).

[0045] Figure 4 This is the sectional view of the first drop water section (partial), the second platform section and the second drop water section (partial) unfolded along the side wall in a certain example of the present invention.

[0046] Figure 5 It is Figure 4 the B-B sectional view.

[0047] Figure 6 This is the floor step steel bar drawing of a standard drop water section in a certain example of the present invention.

[0048] Figure 7 It is Figure 6 the A-A sectional view.

[0049] Figure 8 This is the large-scale drawing of the cover plate step in a certain example of the present invention.

[0050] Figure 9 This is the cover plate steel bar drawing in a certain example of the present invention.

[0051] Figure 10 It is Figure 9 the A-A sectional view.

[0052] Figure 11 It is Figure 1 the sectional view of the structural central axis designed according to the deep-buried culvert scheme in the example of

[0053] Figure 12 This is another example of the present invention.

[0054] Reference numerals: 1, single wing wall; 2, platform section; 3, drop water section; 4, slope; 5, artificial fill foundation or natural stable formation; 6, culvert; 7, cover plate; 8, side wall; 9, floor; 10, cushion; 11, floor step; 12, cover plate step; 13, newly added box culvert; 14, newly added drop well; 15, rockfill foundation; 2-1, the first platform section; 2-2, the second platform section; 2-3, the third platform section; 2-4, the fourth platform section; 2-n, outlet platform section; 3-1, the first drop water section; 3-2, the second drop water section; 3-3, the third drop water section; 3-4, the fourth drop water section. Detailed implementation manners

[0055] To enable those skilled in the art to better understand the technical solution of the present invention, the preferred implementation of the present invention will be described below in conjunction with specific embodiments. However, it should be understood that the drawings are only for illustrative purposes and cannot be construed as a limitation on this patent; for better illustration of this embodiment, some components in the drawings will be omitted, enlarged or reduced, which do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known components and descriptions may be omitted in the drawings. The positional relationships described in the drawings are only for illustrative purposes and cannot be construed as a limitation on this patent.

[0056] Referring to Figure 1 As shown, a combined structure of a pedestrian path and a drop water outlet includes a straight wall 1, a platform section 2 and a drop water section 3. The whole structure is placed inside an engineering slope 4, and the top elevation of each section is flush with the slope 4, and the bottom is placed on a compacted artificial fill foundation or a natural stable stratum 5. The straight wall 1 is close to the outlet of the culvert 6 and together with the first platform section 2-1 forms a closed space. Each platform section 2 and drop water section 3 are connected in sequence, and the end is an outlet platform section 2-n. In different application examples, the lengths and numbers of the platform section 2 and the drop water section 3 are different.

[0057] Preferably, the bearing capacity of the fill foundation or the natural stable stratum 5 should be not less than 100 Mpa.

[0058] Referring to Figures 2 - 5 As shown, both the platform section 2 and the drop water section 3 include four components: a cover plate 7, side walls 8, a bottom plate 9, and a cushion layer 10 from top to bottom. Among them, the bottom plate 9 is directly poured on the gravel cushion layer 10, and the side walls 8 are poured on the bottom plate 9 and are separated on both sides, together with the bottom plate 9 forming a water passage space, and the cover plate 7 is placed on the side walls 8 on both sides. Among them, the cover plate 7, side walls 8, bottom plate 9, and cushion layer 10 are a reinforced concrete cover plate, a concrete side wall, a reinforced concrete bottom plate, and a gravel cushion layer 10 respectively.

[0059] Preferably, the cover plate 7 and the bottom plate 9 are made of C30 concrete, and the side walls 8 are made of C20 concrete.

[0060] Furthermore, the bottom plates 9 of the platform section 2 and the drop water section 3 are flat and stepped respectively.

[0061] Furthermore, the platform section 2 is segmented in sections of about 5 m, and the drop water section 3 is segmented in sections of 3 to 5 bottom plate steps 11. The joints between the segments are deformation joints and need to be treated with waterproof structures.

[0062] Referring to Figure 1 As shown, furthermore, the width and height of the bottom plate steps 11 of the drop water section 3 should be adapted to the slope ratio of the slope 4, so that the entire outlet structure can be naturally integrated into the engineering system.

[0063] Referring toFigures 2 - 5 As shown, further, the top elevation of the bottom plate 9 of the platform section 2 remains unchanged, and the side wall 8 can be provided with a multi-level cover step 12 according to the specific situation of the location to facilitate the connection with the waterfall section 3 or the culvert 6 exit, or the height of the side wall 8 can be kept unchanged, and the upper cover plate 7 is arranged flat and closely to form a recreational platform.

[0064] Reference Figure 6 As shown, further, the side wall 8 of each bottom step 11 of the waterfall section 3 is divided into two to three sections of different heights, and a cover plate 7 is placed at each height, thereby forming a stair walkway for pedestrians to climb.

[0065] Furthermore, the cover plate 7 is a prefabricated cover plate, and hanger bars are pre-embedded on both sides of the top.

[0066] Preferably, the suspension bar is in the shape of Ω and is made of HPB300 grade Steel bars: 4 hanger bars are embedded in each cover plate.

[0067] Reference Figure 8 As shown, the width of the cover plate 7 is 30 cm to 50 cm, and the height of each cover plate step 12 is 10 to 20 cm.

[0068] In a second aspect, the present invention provides a design method for a tourist walkway and a waterfall integrated water outlet, referring to Figures 1 - 10 The engineering example of the present invention comprises:

[0069] 1) According to the location of the outlet of culvert 6, determine the location of the straight wall 1.

[0070] 2) According to the 6-aperture diameter of the culvert, calculate the cross-sectional area of ​​the outlet structure, which should satisfy the minimum water flow area of ​​the outlet structure Qc / effective water flow area of ​​the culvert Qj ≥ 1.2.

[0071] The effective water flow area of ​​the culvert is Qj = 1.8*2.5 = 4.5 m2;

[0072] The minimum water flow area of ​​the outlet structure is Qc≥1.2*Qj=5.4㎡.

[0073] 3) The net height H0 of the outlet should be in the range of 1m to 3m, and the net width B0 should not be less than the net width or diameter of the culvert 6, and Qc = H0*B0. Considering that the outlet structure also serves as a pedestrian walkway, refer to the restrictions on the width of the sidewalk in the urban road design specifications, B0 ≥ 3m. The net cross-sectional dimensions of the outlet structure are preliminarily determined.

[0074] Temporarily assume B0 = 4m, then H0 ≥ Qc / B0 = 1.35m. H0 should be rounded up to the nearest integer based on the modulus of 0.5m, so H0 = 1.5m.

[0075] 4) Determine the width and height of the bottom plate step 11 and the cover plate 7 of the drop section 3 according to the following constraints:

[0076] 4.1) To ensure comfortable climbing for pedestrians, the height Hg of the cover slab steps should satisfy 10 cm ≤ Hg ≤ 20 cm.

[0077] 4.2) To make the outlet structure adapt to the slope ratio of slope 4 and blend into the overall project without being obtrusive, the height Hd of the bottom slab steps 11: the width Bd of the bottom slab steps 11 = the height Hg of the cover slab steps 12: the width Hg of the cover slab steps 12 = the slope ratio of the slope 4 where it is located 1:n.

[0078] 4.3) Every 2 to 3 levels of cover slab steps 12 correspond to one level of bottom slab steps 11. Therefore, Hd = 2 or 3 * Hg, and Bd = 2 or 3 * Bg.

[0079] 4.4 Hd, Hg, Bd, and Bg should all be rounded to facilitate construction.

[0080] 5) When the outlet structure passes through slopes 4 with multiple different slope ratios, repeat step 4 according to their slope ratios 1:n1, 1:n2, 1:n3... to obtain 1 to 2 types of cover slab 7 sizes that are as universal as possible. By unifying the cover slab 7 sizes, adjust the sizes of the cast-in-place side wall 8 and the bottom slab steps 11, so as to facilitate the batch prefabrication of the cover slab 7, saving cost and construction period.

[0081] In this example, the slope ratios of slope 4 where it is located include 1:2.5 and 1:1.5.

[0082] Temporarily take Hg = 20 cm, then the corresponding Bd values are 50 cm and 30 cm respectively. Among them, the cover slab 7 with Bd = 50 cm is type A cover slab 7, and its corresponding bottom slab steps 11 are taken according to 2 levels of cover slab steps 12. Therefore, Hd = 2 * Hg = 40 cm, and Bd = 2 * Bg = 100 cm. The cover slab 7 with Bd = 30 cm is type B cover slab 7, and its corresponding bottom slab steps 11 are taken according to 3 levels of steps 11. Therefore, Hd = 3 * Hg = 60 cm, and Bd = 3 * Bg = 90 cm.

[0083] The thickness of the cover slab 7 is taken as 15 cm. The clear span of the cover slab 7 = B0 = 4 m. The cover slab 7 is supported on the side wall 8, and the unilateral support width Bz = 20 cm. The total slab width = B0 + 2 * Bz = 4.4 m.

[0084] 6) Arrange the platform section 2 and the drop section 3 of the outlet structure in the structural cross-section diagram. It is connected to the outlet of the culvert 6 and the wing wall 1 at the top and reaches the specified drainage elevation at the bottom. The sections are connected end to end, and the top elevation of the cover slab 7 should be as level as possible with the slope 4 and the engineering platform. The side wall 8 of the first platform section 2-1 needs to be designed with multiple levels of cover slab steps 12 in combination with the slope 4 where it is located. The main heights of the side walls 8 of the remaining platforms are the same, but several levels of cover slab steps 12 can be set at the head and tail according to the need to connect to the drop section 3.

[0085] 7) Since the present invention allows pedestrians to pass through, which is different from the conventional culvert outlet that does not bear pressure and also different from the slab culvert that only bears earth pressure, it is necessary to calculate the force on the slab 7 and check the reinforcement. The specific steps are as follows:

[0086] 7.1) Refer to the calculation standard of crowd load in road and bridge design, and calculate the live load per meter of the slab q = crowd load;

[0087] 7.2) Calculate the dead load per meter g = unit weight of the slab * thickness of the slab using the cross-section design parameters of the slab 7 determined in step 5;

[0088] 7.3) Calculate the internal force of the slab 7

[0089] The extreme value of bending moment in the ultimate limit state of bearing capacity Md = (0.15 * g + 0.175 * q) * B0 2

[0090] The extreme value of shear force Vd = (0.6 * g + 0.7 * q) * B0

[0091] The extreme value of bending moment in the normal use limit state Ms = 0.125 * (g + q) * B0 2

[0092] 7.4) Trial - match the longitudinal reinforcement of the slab (7) in the direction perpendicular to the water flow, and check the height of the concrete compression zone, reinforcement ratio, flexural bearing capacity of the normal section and the crack width in the normal use limit state according to the reinforced concrete flexural member.

[0093] In this example, the live load per meter of the slab q = 3 kN / m;

[0094] The dead load per meter g = 25 kN / m 3 * 0.15 m = 3.75 kN / m;

[0095] The extreme value of bending moment in the ultimate limit state of bearing capacity Md = (0.15 * 3.75 + 0.175 * 3) * 42 = 17.4 kNm

[0096] The extreme value of shear force Vd = (0.6 * 3.75 + 0.7 * 3) * 4 = 17.4 kN

[0097] The extreme value of bending moment in the normal use limit state Ms = 0.125 * (3.75 + 3) * 42 = 13.5 kNm

[0098] Trial - match the main reinforcement of HPB300 grade @10.5, then 10 main reinforcements are arranged per meter, and the total area of the reinforcement is 2.5434 * 10 -3 ㎡; the effective height of the cross - section h0 = thickness of the slab - cover - outer diameter of the reinforcement / 2 = 0.101 m

[0099] ① Check the height of the concrete compression zone:

[0100] x = tensile strength of steel * total area of selected steel bars / compressive strength = 4.98 cm

[0101] The relative boundary compression zone height coefficient of HPB300 steel bars is 0.56

[0102] x ≤ compression height coefficient boundary * h0 = 5.66 cm, and the height of the concrete compression zone meets the specification requirements

[0103] ② Minimum reinforcement ratio

[0104] Ps = 100 * total area of steel bars / h0 / b = 2.520%

[0105] Ps = 2.520%, ≤ 45 * tensile strength / tensile strength of steel bars = 0.232%, and ≥ 0.2%, and the main reinforcement ratio meets the specification requirements.

[0106] ③ Check the flexural bearing capacity of the normal section

[0107] The calculation of the flexural bearing capacity of the normal section of the flexural member is as follows:

[0108] Compressive strength * 1000 * b * x * (h0 - x / 2) = 52.294 kNm > Md = 17.4 kNm, and the flexural bearing capacity of the normal section meets the specification requirements.

[0109] 0.7 * βh * cover width * tensile strength * h0 * 1000 = 98.273 kN > Vd = 17.4 kN, and the shear resistance of the inclined section meets the specification requirements, and it is not necessary to improve the shear bearing capacity by configuring stirrups.

[0110] ④ Check the crack width of the normal use limit state

[0111] Ms = 13.5 kNm, Ns = NL = 0 kN, C1 = 1.0, C2 = 1.5, C3 = 1.15

[0112] The crack width Wtk = 0.083 mm ≤ 0.2 mm, and the crack width meets the specification requirements.

[0113] In the present invention, the outlet open channel is covered with a cover plate that also serves as a pedestrian path for tourists. It is beautiful and practical while eliminating the safety hazard of tourists accidentally falling in. At the same time, in this example project, there are 6 such culverts within the 350-meter-long revetment. If the existing long outlet scheme is used for design, the revetment will be cut into 7 parts, and there will be an open channel long ditch cutting off the revetment landscape every about 50 meters. From this comparison, it can be clearly seen that the application of the present invention greatly saves the slope protection space and the viewing platform space, and protects the integrity of the project landscape.

[0114] Refer toFigure 11 , in this example, the deep-buried culvert scheme is adopted, and 86 meters of box culverts and 4 drop wells (28 meters in total) need to be added. Calculated according to 302 kg of HRB400 steel bars per linear meter of box culvert / drop well project quantity, the project quantity of the deep-buried pipe culvert scheme is shown in the second column of the following table, while the project quantity of the present invention is shown in the third column of the following table. By comparing the two, it can be seen that the present invention greatly saves engineering materials.

[0115]

[0116] For the deep-buried culvert scheme (all structures need to be cast-in-place), the cover plate of the present invention adopts a precast structure, shortening the construction period by about one-third.

[0117] The deep-buried culvert scheme needs to adopt a rock-filled foundation, and the foundation bearing capacity requirement is above 250 Mpa. However, the foundation of the present invention can adopt a compacted artificial filled soil foundation or a natural stable stratum, and the foundation bearing capacity requirement is only 100 Mpa. Considering that the price of stone is much higher than that of fill soil, and the construction equipment and labor cost of the rock-filled foundation are also much higher than those of the fill soil foundation, the cost is further reduced in terms of foundation construction.

[0118] Refer to Figure 12 (Another application example of the present invention), the ladder and cover plate of the present invention are both modular, with high degrees of freedom, and can be easily modified to match different slope ratios and platform lengths, having a wide range of applications.

[0119] The stepped shape of the present invention fits closely with the embankment / retaining structure, is not easy to slip, and at the same time, the design of continuous steps has good energy dissipation effect for water drops, especially suitable for projects in high-steep slopes and mountainous areas.

[0120] The independent cover plate is convenient to disassemble, replace and maintain in the later stage.

[0121] The above are only the preferred implementation schemes of the present invention, but the present invention is not limited to the above specific implementation schemes. Those of ordinary skill in the art can make several modifications, supplements or use similar methods to replace them without departing from the principle of the present invention, and these should also be regarded as the protection scope of the present invention.

Claims

1. A design method for an integrated outlet structure of a tourist footpath and a water drop, characterized in that, the whole structure is placed inside the slope (4) of the riverside project, and its bottom is placed on the compacted artificial fill foundation or natural stable formation (5); the structure includes a headwall (1), and the headwall (1) is arranged close to the outlet of the culvert (6); a plurality of platform sections (2) are arranged at intervals along the slope direction of the slope (4) from top to bottom below the headwall (1), the uppermost platform section (2) is arranged close to the headwall (1) and forms a closed space with it, and the lowermost platform section (2) is set as the water outlet; a water drop section (3) is connected between two adjacent platform sections (2), and both the platform section (2) and the water drop section (3) include a cover plate (7), side walls (8), a bottom plate (9) and a cushion layer (10), the bottom plate (9) is poured on the cushion layer (10), the side walls (8) are poured and separated on both sides of the bottom plate (9) and jointly form a water passage space with the bottom plate (9), and the cover plate (7) is placed on the side walls (8) on both sides; the cover plate (7) of the platform section (2) can form a recreation platform for pedestrians to rest; the cover plates (7) of the water drop section are arranged in a graded manner with a gradient along the slope direction of the slope (4) on the side walls (8) to form a stepped footpath for pedestrians to climb; The design method for the integrated outlet structure of the tourist footpath and the water drop includes: 1) Determine the positioning of the headwall according to the position of the culvert outlet; 2) Calculate the cross-sectional area of the outlet structure according to the culvert aperture, and it should satisfy that the minimum water passing area Qc of the outlet structure / the effective water passing area Qj of the culvert ≥ 1.2; 3) The value range of the net water passing height H0 of the outlet is preferably 1 m to 3 m, the net width B0 should not be less than the net width or diameter of the culvert, and Qc = H0 * B0; considering that the outlet structure also serves as a pedestrian footpath, B0 ≥ 3 m, and thus initially determine the net cross-sectional dimensions of the outlet structure; 4) Determine the width and height values of the bottom plate steps and cover plates of the water drop section according to the following limiting conditions: 4.1) To make it comfortable for pedestrians to climb, 10 cm ≤ the step height Hg of the cover plate ≤ 20 cm; 4.2) To make the outlet structure adapt to the slope ratio of the slope and blend into the overall project without being obtrusive, there should be the step height Hd: the step width Bd = the step height Hg: the step width Hg = the slope ratio of the slope where it is located 1:n; 4.3) Every 2 to 3 steps correspond to one step, so Hd = 2 or 3 * Hg, Bd = 2 or 3 * Bg; 4.4) Hd, Hg, Bd, and Bg are all preferably taken as integers for easy construction; 5) When the outlet structure passes through slopes with multiple different slope ratios, repeat step 4) according to their slope ratios 1:n1, 1:n2, 1:n3... to obtain 1 to 2 kinds of cover plate sizes that are as universal as possible. By unifying the cover plate sizes, adjust the sizes of the cast-in-place side walls and bottom plate steps, so as to facilitate the batch prefabrication of the cover plates; 6) It is necessary to perform force calculation and reinforcement calculation on the cover plate, and the specific steps are as follows: 6.1) Refer to the crowd load calculation standard in the road and bridge design, and calculate the live load q per meter of the plate = crowd load; 6.2) Use the cover plate section design parameters determined in step 5) to calculate the dead load per linear meter g = cover plate bulk density * cover plate thickness; 6.3) Calculate the internal force of the cover plate The extreme value of the bending moment Md under the ultimate limit state of bearing capacity = (0.15*g + 0.175*q)*B0 2 Shear force extreme value Vd = (0.6*g+0.7*q)*B0 The extreme value of the bending moment Ms under the serviceability limit state = 0.125 * (g + q) * B0 2 ; 6.4) Try to match the force-bearing reinforcement of the cover plate perpendicular to the direction of water flow, and verify the height of the concrete compression zone, reinforcement ratio, bending bearing capacity of the positive section and crack width in the normal service limit state according to the reinforced concrete bending member.

2. The design method of the integrated water outlet structure of the tourist walkway and waterfall according to claim 1, Features: The bottom plates (9) of the platform section (2) and the drop section are respectively a flat bottom plate and a stepped bottom plate.

3. The design method of the integrated water outlet structure of the tourist walkway and waterfall according to claim 2, Features: The platform section (2) is divided into sections of 4-6 m, and the drop section is divided into sections of 3 to 5 bottom plate steps (11). The sections are used as deformation joints and waterproof structural treatment is required.

4. The design method of the integrated water outlet structure of the tourist walkway and waterfall according to claim 2, Features: The ratio of the width to the height of each level of the bottom plate steps (11) in the drop section should be adapted to the slope ratio of the side slope (4).

5. The design method of the integrated water outlet structure of the tourist walkway and waterfall according to claim 2, Features: The side wall (8) corresponding to each bottom plate step (11) in the waterfall section is divided into two to three sections with different heights, and a cover plate (7) is placed on the side wall (8) at each height, thereby forming a staircase walkway for pedestrians to climb.

6. The design method of the integrated water outlet structure of the tourist walkway and waterfall according to claim 1, Features: The cover plates (7) of the platform section (2) and the drop section (3) are both prefabricated cover plates, and hanger bars are pre-embedded on both sides of the top of the prefabricated cover plates.

7. The design method of the integrated water outlet structure of the tourist walkway and waterfall according to claim 1, Features: The width of the cover plate (7) is 30-50 cm, and the height of each cover plate step (12) in the drop section (3) is 10-20 cm.

8. The design method of the integrated water outlet structure of the tourist walkway and waterfall according to claim 1, Features: The bearing capacity of the artificial fill foundation or the natural stable stratum (5) should be no less than 100 MPa.

9. The design method of the integrated water outlet structure of the tourist walkway and waterfall according to claim 1, Features: The top surfaces of the platform section (2) and the drop section (3) are both flush with the surface of the slope (4).

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