Construction method of high fill slope

Abstract

The application relates to a construction method of a high-filled slope, which comprises the following construction steps: S00, determining a construction area, and leveling a site to a design elevation; S10, determining intersection coordinates of a potential most dangerous fracture surface and a current layer and marking and laying out; S20, hoisting a prefabricated concrete box at the marked and laid-out position; or erecting a permanent formwork at the marked and laid-out position and pouring concrete to form a cast-in-place concrete box; S30, performing Bing stone cage construction on each level of slope surface; S40, performing platform and drainage ditch construction between adjacent two levels of slope; S50, circulating the steps S10-S40 until the slope top is reached; and S60, pouring a concrete surface layer on the slope top to complete the construction. The application can avoid backfilling slope shallow layer sliding collapse, improve a slope body deep layer sliding safety coefficient, avoid the problems of a long time period and great difficulty in conventional large anti-slide pile construction, and avoid using a reinforced soil retaining wall which is relatively difficult to control in construction quality.

Description

Technical Field

[0001] This application relates to the field of civil engineering technology, specifically to construction methods for high embankment slopes. Background Technology

[0002] With the deepening of the Belt and Road Initiative, many infrastructure projects have been launched in mountainous areas of my country. The problem of high fills and deep excavations in mountainous areas is unavoidable. To ensure the relative stability of slopes and reduce earthwork volume during construction, conventional high fill slopes typically employ slope protection or reinforced earth retaining walls, resulting in gentler slopes and larger land occupation. For the support of natural slopes, only anti-slide piles or other retaining structures are generally available, making large-scale excavation and filling projects inconvenient.

[0003] The backfill material used in high fill slopes is relatively uniform, which can lead to certain deep and shallow sliding failures. How to efficiently utilize the existing backfill material in the local area, improve the overall strength of the material, and complete the slope treatment through simple slope setting and support structure is a very important research topic.

[0004] Application content

[0005] The purpose of this application is to address the aforementioned problems existing in the prior art by providing a construction method for high embankment slopes.

[0006] To achieve the aforementioned objectives, this application employs the following technical solution: The construction method for high embankment slopes includes the following construction steps:

[0007] S00. Determine the construction area and level the site to the design elevation;

[0008] S10. Determine the intersection coordinates of the potentially most dangerous fracture surface with the current layer and mark and stake it out;

[0009] S20. At the marked and laid-out location, the precast concrete box body is hoisted, and then backfill soil is used to fill and compact the precast concrete box body and the slopes at all levels in layers; or permanent formwork is erected at the marked and laid-out location and concrete is poured to form a cast-in-place concrete box body. After the cast-in-place concrete box body has been cured, backfill soil is used to fill and compact the cast-in-place concrete box body and the slopes at all levels in layers.

[0010] S30. Construct gabion cages on slopes at all levels;

[0011] S40. Construct platforms and drainage ditches between adjacent slope levels;

[0012] S50, repeat steps S10~S40 until construction reaches the top of the slope;

[0013] S60. Pour the concrete surface layer at the top of the slope to complete the construction.

[0014] Furthermore, in step S10, the specific steps for determining the potentially most dangerous fracture surface are as follows:

[0015] Based on the limit equilibrium theory, the stability analysis of the high fill slope formed by backfilling is carried out and the intersection coordinates with the current layer are obtained;

[0016] The simulation sets up a concrete box in the intersection area of ​​two sliding zones with the minimum safety factor, and continuously adds concrete boxes to the newly generated sliding surface. At the same time, the safety factor after adding concrete boxes and the corresponding new sliding surface position are calculated.

[0017] The stability of high embankment slopes is judged based on the calculated slope safety factor until the safety factor of the sliding surface with the smallest safety factor meets the design requirements.

[0018] Furthermore, in step S20, the top and bottom of the concrete box are through holes, and the sides are surrounded by side panels and panel connecting members, and the side panels of multiple concrete boxes are connected sequentially by connecting panel connecting members.

[0019] Furthermore, in step S20, the concrete box is continuously installed along the slope axis and settlement joints are provided.

[0020] Furthermore, in step S20, the specific steps for hoisting the precast concrete box are as follows:

[0021] In the fill area, where precast concrete boxes need to be installed, the side panels and panel connecting components are hoisted and assembled to form three complete side walls, leaving one side empty.

[0022] Simultaneously, soil was filled inside and outside the box;

[0023] For each fill height, the side panels are connected using panel connecting components;

[0024] Continue until the backfill of this level of slope reaches the design elevation.

[0025] Furthermore, in step S20, during the compaction of the backfill soil, the compaction degree of the completed area is tested, and the soil is continuously re-compacted until the compaction degree meets the design requirements.

[0026] Furthermore, the filler layer thickness is 300mm, and the compaction coefficient is not less than 0.95.

[0027] Furthermore, in step S30, the specific steps for constructing gabions on slopes at all levels are as follows:

[0028] Measure and lay out the gabions, and place them in a staggered pattern on the leveled slopes of each level.

[0029] Erect the four sides of the gabion and lock the adjacent edges with binding wire. When binding, twist the binding wire around the two overlapping frame lines or the double twisted edge of the frame line and the gabion in a spiral shape.

[0030] The gabions were filled with boulders;

[0031] After filling the gabion with stones, the top cover is placed on top, and then the two overlapping frame lines are twisted tightly in a spiral with binding wire.

[0032] Fine-grained clay soil is laid on the constructed gabions to facilitate grass planting.

[0033] Furthermore, in step S10, the stability analysis of the high slope formed by backfill is performed using the automatic location search method of SLOPE / W in GeoStudio, with the analysis type being Morgenstern-Price and the inter-strip force function being a half-sine function.

[0034] Furthermore, the width of each platform level is 1.5~2.5m.

[0035] Compared with the prior art, this application has the following beneficial effects:

[0036] 1. This application makes full use of the embankment slope construction process by burying precast concrete boxes within a certain range of the most dangerous potential fracture surface of the high embankment slope and filling them with backfill soil, thereby improving the shear strength of the slope backfill material and avoiding concentrating all reinforcement measures on the slope toe; or by setting permanent formwork (such as profiled thin steel plate formwork and reinforced concrete thin plate) during construction to shape and support the newly poured concrete, which can reduce the formwork erection and dismantling, save a lot of formwork materials and formwork erection and dismantling work, reduce the labor intensity of formwork erection and dismantling, and facilitate embankment operations. After the concrete hardens, the permanent formwork and the concrete box share the load and jointly resist the slope deformation.

[0037] 2. This application, combined with gabion technology, avoids shallow sliding and collapse of backfilled slopes and improves the safety factor of deep sliding of the slope.

[0038] 3. This application adopts the method of pre-embedded reinforcement, which allows reinforcement to be arranged arbitrarily throughout the entire process of slope filling, and can also avoid the problems of time cycle and high difficulty in the construction of conventional large anti-slide piles;

[0039] 4. The method of pre-embedded reinforcement in this application has the advantage of making the fill slope more advantageous than natural slope in that the anti-sliding structure can be conveniently arranged and buried at any position inside the slope during the slope filling process. Therefore, it can more effectively break the potential sliding surface, increase the slope ratio, save land, and avoid the use of reinforced soil retaining walls, which are relatively difficult to control in terms of construction quality. Attached Figure Description

[0040] Figure 1 This is a construction flowchart of this application;

[0041] Figure 2 This is a schematic diagram of the high fill slope structure in this utility model;

[0042] Figure 3 This is a schematic diagram of the drainage ditch in this application;

[0043] Figure 4 This is a schematic diagram of the gabion in this application;

[0044] Figure 5 This is a top view of the concrete box in this application;

[0045] Figure 6 This is a schematic diagram of the most dangerous fracture surface calculated using SLOPE / W in GeoStudio in Example 1 after reinforcing the slope with a concrete box girder.

[0046] In the diagram, 1. Existing slope; 2. Slope top; 3. Side slope; 4. Platform; 5. Backfill soil; 6. Final slope; 20. Drainage ditch; 30. Gabion; 31. Gabion cover; 32. Internal partition; 33. Side junction; 40. Concrete box; 41. Side panel; 42. Panel connecting component one; 43. Panel connecting component two. Detailed Implementation

[0047] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0048] Those skilled in the art should understand that, in the disclosure of this application, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on this application.

[0049] like Figure 1-6 As shown, the construction method for this high fill slope includes the following steps:

[0050] S00. Determine the construction area and level the site to the design elevation;

[0051] S10. Determine the intersection coordinates of the potentially most dangerous fracture surface with the current layer and mark and stake it out;

[0052] Preferably, in step S11, after setting up a concrete box on the first floor, the slope safety factor also increases, the potential most dangerous rupture surface changes, bypassing the concrete box to form a new potential most dangerous rupture surface, and the intersection coordinates of the new potential most dangerous rupture surface and the second floor are recorded and marked for layout.

[0053] S12. After the concrete box is set in the second layer, the slope safety factor increases again, and the potential most dangerous failure surface changes again. It bypasses the concrete box and forms a new potential most dangerous failure surface. Record the intersection coordinates of the new potential most dangerous failure surface and the third layer and mark and lay out.

[0054] S13, and so on, until the safety factor of the high embankment slope meets the requirements. Alternatively, concrete box girder enclosures can be installed every other layer or every few layers, as long as the final slope safety factor meets the design requirements.

[0055] In this embodiment, the calculation of the potentially most dangerous rupture surface can be determined by calculation software, which is existing technology. Based on the limit equilibrium theory, the automatic location search method for the most dangerous sliding surface is used in GeoStudio's SLOPE / W, with the analysis type being Morgenstern-Price and the inter-strip force function being a half-sine function. Stability analysis is performed on the high slope 3 formed by backfill. Concrete boxes 40 are set in the intersection area of ​​the two sliding zones with the smallest safety factor. Concrete boxes 40 are continuously added to the newly generated sliding surface. The stability of the high fill slope 3 is judged using the calculated safety factor of slope 3 until the safety factor of the most dangerous sliding surface meets the design requirements.

[0056] For example, the result of SLOPE / W calculation in GeoStudio used in this embodiment is as follows: Figure 6 As shown:

[0057] Through measurement, the calculated coordinates of the sliding center of the potentially most dangerous fracture surface are X = 43.15m and Y = 41.015m, and the radius of the sliding arc is R = 40.83m (relative to the origin). Figure 6 (The intersection of the bottom and side surfaces of the slope) can be used to draw the fracture surface represented by the safety factor of the slope after the concrete box is reinforced by 40.

[0058] SLOPE / W is a module in GeoStudio software used for analyzing stable slopes. This module helps engineers and geologists assess slope stability, evaluate potential landslide or rockfall risks, and design related earthwork or other civil engineering projects. The SLOPE / W module uses finite element analysis (FEM) techniques and modern stability analysis methods to calculate slope stability, considering the properties of different types of soil and rock, including their strength, friction angle, and permeability. By using the SLOPE / W module, users can evaluate the impact of different slope geometries, soil or rock properties, and additional loads on slope stability and make appropriate design and improvement decisions.

[0059] One method for automatically locating and searching for the most dangerous sliding surface is to perform finite element analysis on the slope, calculate the stability index of the sliding surface at different locations and angles, and thus automatically search for the location and angle of the most unstable sliding surface.

[0060] In the Morgenstern-Price model, the soil is assumed to be a continuous medium, subjected to gravity in equilibrium, and possessing both elastic stress and plastic strain fields. A half-sine function is used as the inter-strip force function, representing the relationship between shear stress and normal stress in the soil across horizontal intervals.

[0061] When performing stability analysis using SLOPE / W, users need to define the slope geometry, the physical and mechanical properties of the soil and rock, and other loading and boundary conditions. Users can then use the automatic location search method to calculate the slope's stability and obtain results regarding the location of the most unstable slip surface, its dip angle, and safety factors. These results can help users assess the slope's stability and make necessary design and improvement decisions.

[0062] S20. At the marked and laid-out location, the precast concrete box 40 is hoisted, and then backfill soil 5 is used to fill and compact the precast concrete box 40 and the slopes at all levels in layers; or permanent formwork is erected at the marked and laid-out location and concrete is poured to form a cast-in-place concrete box. After the cast-in-place concrete box has been cured, backfill soil is used to fill and compact the cast-in-place concrete box and the slopes at all levels in layers.

[0063] In this embodiment, at the location where the concrete box 40 needs to be installed in the fill area, two side wall panels and panel connecting component 2 43 are hoisted and assembled to form three complete side walls. Another area of ​​the box 40, where the side walls are not yet installed, allows earthmoving vehicles and compaction equipment to enter and exit. Backfilling inside and outside the box needs to be carried out simultaneously to prevent soil pressure from overturning the side walls. Every certain height of backfilling inside and outside the box (e.g., every 0.5m~1m of backfilling height), the side panels 41 are connected using panel connecting component 1 42, increasing overall stability and preparing for the connection of the next level of box 40. This increases the overall elevation by 0.5m~1m; this process is repeated until the backfilling of the current slope 3 reaches the design elevation.

[0064] Preferably, the concrete box body 40 is open at the bottom and top, and is assembled from two side panels 41 and two panel connecting members. The box body is continuously installed along the slope 3 axis and settlement joints are provided. The side panels 41 are connected step by step through panel connecting member 1 42, the height of which is 0.5m to 1.0m. The end side panels 41 are connected through panel connecting member 2 43, the height of which is the same as that of the side panels 41.

[0065] Preferably, the specific requirements for compaction are as follows:

[0066] 1) Pre-construction preparation: Clear obstacles from the site and level the surface. Select appropriate construction machinery based on the characteristics of the backfill soil 5 and design requirements. Determine parameters such as the number of compaction passes and loose-lay thickness based on on-site compaction tests. Lay the material using dump trucks and level it with bulldozers. The proposed loose-lay thickness is 30cm, but adjustments will be made based on site conditions during actual construction.

[0067] 2) Construction compaction: The backfill soil 5 is transported to the construction site and spread. The fill material is compacted in layers. The compaction is carried out by vibration compaction. When compacting, start with light compaction and then increase the intensity, start with the two sides and then the middle, start slowly and then increase the speed, and control the compaction speed of the construction equipment.

[0068] Within a 0.8m radius around the 40mm perimeter of the concrete box, in areas with narrow working surfaces, manual layering is used for paving and compaction using a plate vibrator or frog-type rammer, followed by manual leveling. In areas with wide working surfaces, mechanical paving is used followed by compaction with a road roller. During construction, the roller is typically used with 1 / 2 to 1 / 3 of its length for reciprocating compaction, and the rear roller must extend beyond the joint between two construction sections.

[0069] The process proceeds from the outside inwards until the required density and physical and mechanical properties are achieved. Settlement joints are made at intervals according to the dimensions of each concrete box 40 to prevent the concrete box 40 from being squeezed and deformed by machinery during leveling. The joints are 2-3cm wide and filled with asphalt-impregnated hemp fiber along the inside and outside of the joints, with a filling depth of not less than 15cm.

[0070] 3) Compaction degree test: The compaction degree of the rolled area shall be tested. The thickness of the fill layer shall be 300 mm, and the compaction coefficient λc shall not be less than 0.95 to ensure construction quality. If the construction quality requirements specified in the design are not met, rolling shall continue until the construction quality requirements are met.

[0071] Preferably, a weighted calculation method is used to determine the comprehensive shear strength parameters of the concrete box 40 and its internal backfill. The shear strength parameters of the internal backfill can be obtained through on-site direct shear tests, while the shear strength parameters of the concrete adopt the standard strength values ​​for each grade. The weighted strength parameters c and φ are expressed as follows:

[0072] tan(φ) = (1-t)×tan(φ) 土 )+t×tan(φ 砼 )

[0073] c = (1-t) × c 土 +t×c 砼

[0074] Where: t is the ratio of the cross-sectional area of ​​the concrete box 40 to the total cross-sectional area of ​​the backfill and the concrete box 40; c is the combined cohesion of the concrete box 40 and the internal backfill; φ is the combined internal friction angle of the concrete box 40 and the internal backfill; φ 土 The internal friction angle of the internal fill; c 土 The cohesion of the internal fill soil; φ 硂 The internal friction angle of the concrete box is 40°; c 硂 The cohesion of the concrete box body 40.

[0075] S30, Construct 30 gabions on all slopes;

[0076] In this embodiment, the specific construction method is as follows:

[0077] 1) Measure and lay out the gabion 30s in a staggered manner on the leveled slopes. Only after all gabion 30s are installed in place should the stones be filled to prevent deformation. The height difference between the stones of two adjacent gabion 30s should not exceed 35cm.

[0078] 2) When placing the gabion 30, avoid longitudinal through seams. Stand the gabion 30 upright on all four sides and lock the adjacent edges with binding wire. When binding, twist the binding wire around the two overlapping frame lines or the double twisted edge of the frame line and the cage in a spiral shape. The pitch should not be greater than 50mm.

[0079] When installing gabion 30 on the completed bottom layer mesh, use binding wire to fix the newly installed gabion 30 to the bottom layer mesh along the lower edge of the mesh. Adjacent gabion meshes on the same layer should also be tied together with binding wire to make the gabion meshes a whole.

[0080] 3) Stone filling: The stone particle size should be between 10 and 25 cm, firm and dense, with strong weather resistance, and the size should be reasonably matched to achieve the required porosity. Exposed stones should be manually laid flat to obtain an aesthetically pleasing surface and prevent water from flowing away from the mesh, ensuring the straight shape of the 30 mesh gabion.

[0081] 4) Close the top cover 31 of the gabion. After filling the gabion 30 with rubble, put the top cover down. Then, use binding wire to twist the two overlapping frame lines in a spiral shape, with a pitch of no more than 50mm. Spread fine-grained clay soil on the constructed gabion 30 for planting grass.

[0082] Among them, the gabion 30 includes a gabion cover 31, an internal partition 32, and a side junction 33.

[0083] S40. Construct the platform 4 and drainage ditch 20 between two adjacent slope levels 3;

[0084] In this embodiment, the height of each level of slope 3 between the top of the slope 2 and the last level of slope 6 is 6-8m, and adjacent levels of slope 3 are transitioned by a cast concrete platform 4, with each platform 4 having a width of 1.5-2.5m.

[0085] S50, repeat steps S10~S40 until construction reaches the top of the slope 2;

[0086] S60. Pour the concrete surface layer at the top of the slope 2 to complete the construction.

[0087] In this embodiment, the high fill slope structure after construction is 30m high, including the top of the slope 2, the last level slope 6, the various levels of slopes 3 between the top of the slope 2 and the last level slope 6, the platform 4 between the two levels of slopes 3, gabions 30, concrete boxes 40, backfill soil 5, the original slope 1, and drainage ditch 20. The height of each level of slope 3 is 7m, and the slope ratio of each level is 1:1.5. Gabions 30 are provided on the slope surface of each level of slope 3.

[0088] Preferably, a drainage ditch 20 is provided in each platform 4, and the depth of the drainage ditch 20 is about 25cm. The height of each level of slope 3 between the top of the slope 2 and the last level of slope 6 is 6~8m, and adjacent two levels of slope 3 are transitioned by a cast concrete platform 4, and the width of each platform 4 is 1.5~2.5m.

[0089] The parts not described in detail in this application are prior art, and therefore are not described in detail in this application.

[0090] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0091] Although this document uses numerous terms such as 1. original slope, 2. slope top, 3. side slope, 4. platform, 5. backfill, 6. final slope, 20. drainage ditch, 30. gabion, 31. gabion cover, 32. internal partition, 33. side junction, 40. concrete box, 41. side panel, 42. panel connection component one, and 43. panel connection component two, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of this application; interpreting them as any additional limitation would be contrary to the spirit of this application.

[0092] This application is not limited to the above-described preferred embodiments. Anyone can derive other products in various forms under the guidance of this application. However, regardless of any changes made to their shape or structure, any technical solution that is the same as or similar to that of this application falls within the protection scope of this application.

Claims

1. A construction method for high embankment slopes, characterized in that, The construction steps include the following: S00. Determine the construction area and level the site to the design elevation; S10. Determine the intersection coordinates of the potentially most dangerous fracture surface with the current layer and mark and stake it out; The specific steps for determining the potentially most dangerous fracture surface are as follows: Based on the limit equilibrium theory, the stability analysis of the high fill slope formed by backfilling is carried out and the intersection coordinates with the current layer are obtained; The simulation sets up a concrete box in the intersection area of ​​two sliding zones with the minimum safety factor, and continuously adds concrete boxes to the newly generated sliding surface. At the same time, the safety factor after adding concrete boxes and the corresponding new sliding surface position are calculated. The stability of high embankment slopes is judged based on the calculated slope safety factor until the safety factor of the sliding surface with the smallest safety factor meets the design requirements. S20. The precast concrete box is hoisted at the marked layout point, and then backfill soil is used to fill and compact the precast concrete box and the slopes at each level in layers; or permanent formwork is erected at the marked layout point and concrete is poured to form a cast-in-place concrete box. After the cast-in-place concrete box has been cured, backfill soil is used to fill and compact the cast-in-place concrete box and the slopes at each level in layers. S30. Construct gabion cages on slopes at all levels; S40. Construct platforms and drainage ditches between adjacent slope levels; S50, repeat steps S10~S40 until construction reaches the top of the slope; S60. Pour the concrete surface layer at the top of the slope to complete the construction.

2. The construction method for high embankment slopes according to claim 1, characterized in that, In step S20, the top and bottom of the concrete box are through holes, and the sides are surrounded by side panels and panel connecting members. The side panels of multiple concrete boxes are connected sequentially by connecting panel connecting members.

3. The construction method for high embankment slopes according to claim 1, characterized in that, In step S20, the concrete box is continuously installed along the slope axial direction and settlement joints are provided.

4. The construction method for high embankment slopes according to claim 2, characterized in that, In step S20, the specific steps for hoisting the precast concrete box are as follows: In the fill area, where precast concrete boxes need to be installed, the side panels and panel connecting components are hoisted and assembled to form three complete side walls, leaving one side empty. Simultaneously, soil was filled inside and outside the box; For each fill height, the side panels are connected using panel connecting components; Continue until the backfill of this level of slope reaches the design elevation.

5. The construction method for high embankment slopes according to any one of claims 2-4, characterized in that, In step S20, during the compaction of the backfill soil, the compaction degree of the completed area is tested, and the soil is continuously re-compacted until the compaction degree meets the design requirements.

6. The construction method for high embankment slopes according to claim 5, characterized in that, The filler layer thickness is 300mm, and the compaction coefficient is not less than 0.

95.

7. The construction method for high embankment slopes according to claim 1, characterized in that, In step S30, the specific steps for constructing gabions on slopes at all levels are as follows: Measure and lay out the gabions, and place them in a staggered pattern on the leveled slopes of each level. Erect the four sides of the gabion and lock the adjacent edges with binding wire. When binding, twist the binding wire around the two overlapping frame lines or the double twisted edge of the frame line and the gabion in a spiral shape. The gabions were filled with boulders; After filling the gabion with stones, the top cover is placed on top, and then the two overlapping frame lines are twisted tightly in a spiral with binding wire. Fine-grained clay soil is laid on the constructed gabions to facilitate grass planting.

8. The construction method for high embankment slopes according to claim 1, characterized in that, In step S10, the SLOPE / W automatic location search method for the most dangerous sliding surface in GeoStudio is used, with the analysis type being Morgenstern-Price and the inter-strip force function being a half-sine function, to perform stability analysis on the high slope formed by backfilling.

9. The construction method for high embankment slopes according to any one of claims 1-4, characterized in that, Each platform has a width of 1.5~2.5m.

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