Karst roadbed treatment system and process thereof

Abstract

The application discloses a karst roadbed treatment system and a process thereof, relates to the karst roadbed treatment field, and can improve the positioning and connecting efficiency of the support, quickly and conveniently fix the support, and improve the quality of concrete pouring.

Description

Technical Field

[0001] This invention relates to the field of karst roadbed treatment, and more specifically to a karst roadbed treatment system and its process. Background Technology

[0002] Karst collapses are widespread in my country, affecting many sectors. Highways, railways, and mines are the most severely affected, followed by farmland irrigation, urban construction, and road and pipeline infrastructure.

[0003] Many highways under construction or in the planning stage inevitably need to pass through karst areas, and the numerous karst caves along the routes bring many difficulties to the construction of roadbeds, bridge foundations and tunnels.

[0004] When treating karst roadbeds, it is usually necessary to pour cement piles and fill the upper roadbed. However, during the concrete pouring process, it is difficult to position the molds when placing them, requiring multiple operators to work together to fix them, which is inefficient. Furthermore, during the operation, the operators are located inside the karst, and accidents are prone to occur when hoisting the cement column molds.

[0005] Meanwhile, during the process of moving the grouting pipe upwards by crane, the grouting pipe is prone to shaking, which in turn affects the pouring of concrete grout, causing air bubbles and hollows in the concrete grout, thus affecting the quality of cement-soil mixing piles. Summary of the Invention

[0006] One objective of this invention is to provide a karst roadbed treatment system and process, which improves the efficiency of support positioning and connection, enables quick and convenient fixation of supports, and improves the quality of concrete pouring.

[0007] This objective is achieved using the following technical solution: A karst roadbed treatment system and its process include a closed surface layer located at the karst opening and a support column located inside the karst. The support column is lifted into the karst by a crane, and the steel bars on the support column are inserted into the connecting groove inside the karst cave by the operator. Since the karst cave is usually small and uneven, it is time-consuming and laborious for the operator to connect the support column and the connecting groove.

[0008] The inventors provide a karst roadbed treatment system. A support column includes connecting steel bars and several first positioning steel bars, with two first positioning steel bars located on opposite sides of the column. A second positioning steel bar is vertically connected to each of the first positioning steel bars, and the second positioning steel bars are parallel to the column. A first connecting groove and a second connecting groove are provided within the karst, corresponding to the connecting steel bars and the second positioning steel bars, respectively. A positioning structure is provided within the second connecting groove, comprising a first positioning structure and a second positioning structure. The second positioning structure is located within the second connecting groove, while the first positioning structure is located outside the second connecting groove. The first and second positioning structures are connected by a telescopic structure, which positions the first positioning structure on the opening surface of the karst or the opening surface of the second connecting groove. The first positioning structure is provided with a first through groove for passing through the support column, and the second positioning steel bar is provided with a second through groove.

[0009] When the support is inserted, the telescopic structure extends, positioning the first positioning structure on the opening surface of the karst.

[0010] The crane lifts the support column above the opening of the karst. One end of the connecting rope is passed through the second through slot of the second positioning steel bar, and then both ends of the connecting rope are passed through the first through slot. By pulling the two ends of the connecting rope, the second positioning steel bar is inserted into the first through slot of the first positioning structure. After insertion, the telescopic structure shortens, so that the first positioning structure is located on the opening surface of the second connecting slot. During the shortening process of the telescopic structure, the support column moves downward together.

[0011] Compared to existing roadbed treatment systems, this system positions the supports before they enter the karst landscape, and operators can work from outside the karst opening without entering the cave, thus avoiding potential accidents during support placement. It also eliminates the need for multiple workers to simultaneously position and support the supports inside the cave, improving operational efficiency.

[0012] Secondly, after the second positioning steel bar is inserted into the first through slot on the first positioning structure above the karst cave, the telescopic structure shortens and, together with the crane, places the support column into the karst cave. The crane bears most of the weight of the support column, while the telescopic structure assists the crane in bearing the weight. Guided by the telescopic structure, the connecting steel bar is inserted into the first connecting slot, and the second positioning steel bar is inserted into the second connecting slot. This improves the positioning and connection efficiency.

[0013] Furthermore, the first positioning structure includes a first positioning plate and a second positioning plate, both of which are provided with a first through groove; an adjustment plate is connected between the first positioning plate and the second positioning plate, the adjustment plate including a first adjustment plate and a second adjustment plate connected at one end to each other, the first adjustment plate and the second adjustment plate being located on the same vertical line or in contact with each other; In the initial state, i.e., without the second positioning reinforcement inserted into the first through slot, the first adjusting plate and the second adjusting plate are located on the same vertical line, with a certain distance between them. When the second positioning reinforcement is inserted into the first through slot, the first positioning reinforcement acts on the first positioning plate, pressing it downwards under the weight of the support. The connection between the first and second adjusting plates rotates, changing them from a vertical to a horizontal state, and they come into contact with each other. At this point, the first positioning plate and the second positioning plate are also in contact. The second positioning reinforcement completes its passage through the first through slot between the first and second positioning plates, achieving initial positioning.

[0014] The first positioning structure not only allows for quick positioning of the support column, but also provides a buffer for the entry of the support column by moving between the first and second positioning plates, thus improving the stability of the entry.

[0015] The second positioning structure includes a third positioning plate located in the second connecting groove. The third positioning plate is provided with a third through groove. The inner diameter of the second positioning steel bar in the second connecting groove gradually decreases from top to bottom. The third positioning plate is provided with a number of positioning blocks, which are in contact with the side of the second positioning steel bar.

[0016] The third positioning plate is used to connect the expansion joint. At the same time, the positioning block contacts the side of the second positioning steel bar to maintain the stability of the insertion, so that the second positioning steel bar can be inserted more stably into the second connecting groove.

[0017] Preferably, a retaining plate is provided at the opening of the second connecting groove, and a retaining groove is provided on the second positioning steel bar. When the lower end of the second positioning steel bar is inserted into the second connecting groove, the retaining plate corresponds to the retaining groove and is inserted into the retaining groove. Further fixing connection is then performed after insertion.

[0018] Furthermore, the support column contains a sandwich structure, which consists of a first hollow layer and a second hollow layer arranged sequentially from the inside out. The sandwich structure is made of expanded perlite material.

[0019] After the supports are connected, concrete is injected into the first and second hollow layers.

[0020] Expanded perlite is an inorganic mineral material characterized by its light weight, good heat insulation and sound absorption properties, abundant raw materials, low price, safe use, and convenient construction.

[0021] When concrete is poured into the first and second hollow layers, it expands when heated. The expanded perlite has a honeycomb structure inside and also has good frost resistance. Because expanded perlite is porous, it can achieve good frost resistance in concrete without air-entraining agents. Applying it to concrete pouring can not only reduce the weight of concrete but also improve its heat insulation and thermal insulation performance.

[0022] In addition, expanded perlite can also be used as a lightweight aggregate, which is more convenient to handle and use during transportation and movement, and the movement is safer and more reliable.

[0023] On the other hand, a karst roadbed treatment process includes the following steps: Obtain the location, size, and type of karst beneath the roadbed; Clean the karst interior; Pre-install slope drainage holes in the karst formations on the road cut slopes; A retaining wall is installed at the roadbed to keep the water out of the roadbed; The caves are reinforced according to their size and type. Based on the location, size, and type of the karst, the pre-set support is placed inside the karst, so that the second positioning steel bar of the support is inserted into the corresponding second connecting groove, and the connecting steel bar is inserted into the corresponding first connecting groove; Concrete is poured into the support column. The column contains a sandwich structure, consisting of a first hollow layer and a second hollow layer arranged sequentially from the inside out. The sandwich structure is made of expanded perlite. The concrete pouring process specifically includes: Simultaneously, concrete is injected into the first hollow layer and the second hollow layer. The grouting pressure in the first hollow layer gradually increases from a preset initial pressure until it reaches a preset final grouting pressure. The grouting pressure in the second hollow layer gradually increases from a preset initial pressure until it reaches a preset final grouting pressure. The grouting pressure in the first hollow layer is greater than that in the second hollow layer.

[0024] After pouring concrete, a retaining wall is laid on the support, and then a layer of crushed stone, a layer of soil, and a layer of planting are laid on the retaining wall in sequence.

[0025] Compared with the prior art, the present invention has the following advantages and beneficial effects: This invention discloses a karst roadbed treatment system and its process. The invention allows for the initial positioning of the support column at the karst opening surface using a first positioning structure. The movement between the first positioning plate and the second positioning plate of the first positioning structure buffers the support column when it enters the karst cave, improving stability. Furthermore, under the action of the telescopic structure, the second positioning steel bar of the support column is directly inserted into the second connecting groove, and the connecting steel bar is inserted into the first connecting groove, improving operational efficiency.

[0026] Meanwhile, the support column of this system is equipped with a sandwich layer, which consists of a first hollow layer and a second hollow layer arranged sequentially from the inside out. The sandwich layer is made of expanded perlite. During the pouring process, the expanded perlite sandwich layer can further act between the first and second hollow layers, making the concrete inside the support column uniform, avoiding air bubbles and hollow areas in the concrete, and improving the quality of the support column. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram illustrating the treatment of karst and karst water-developed areas. Figure 2 This is a schematic diagram of the support structure; Figure 3 This is a schematic diagram of the first positioning structure within the karst located on the opening surface of the karst. Figure 4 A schematic diagram of the structure of the first positioning structure in the karst located on the opening surface of the second connecting groove; Figure 5 This is a schematic diagram of the first positioning structure; Figure 6 A schematic diagram showing the structure of the first and second adjusting plates changing from a vertical to a horizontal state; Figure 7 This is a structural schematic diagram of the second positioning reinforcement bar; Figure 8 This is a schematic diagram of the first positioning structure and the second positioning structure when the second positioning steel bar is not inserted into the first through slot; Figure 9 A schematic diagram of the structure for inserting the card plate into the slot of the second positioning steel bar; Figure 10 A schematic diagram of the structure for inserting the second positioning steel bar into the second connecting groove; Figure 11 This is a schematic diagram illustrating the treatment when the karst is located in an exposed karst area. Figure 12 This is a schematic diagram of the treatment when the karst is located in a shallow karst layer.

[0028] The attached diagram shows the markings and corresponding component names: 1-Karst, 2-Second connecting groove, 3-First connecting groove, 4-Third positioning plate, 5-First positioning plate, 6-Second positioning plate, 7-Telescopic structure, 8-Adjusting plate, 9-Positioning block, 10-Clamping plate, 11-Slide groove, 12-Second positioning steel bar, 121-Clamping groove, 13-First positioning steel bar, 14-Column, 15-Connecting steel bar. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0030] In the description of this invention, it should be understood that the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", "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 invention 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, they should not be construed as limiting the scope of protection of this invention.

[0031] Example 1

[0032] For the treatment of karst located in water-developed areas, such as Figure 1 As shown, for larger karst caves (underground rivers) and shafts that have been exposed or whose top slab thickness is less than the safe thickness, reinforced concrete slabs are used for crossing. For smaller, shallow karst caves and fissured karst formations, reinforced concrete slabs are used for crossing or grouted rubble masonry columns are used for support. Grouted rubble masonry columns can only be used when construction personnel and machinery can access the construction site. The dimensions and spacing of the grouted rubble masonry supports will be designed separately based on the size of the karst cave. The safe distance between the toe of the roadbed and nearby karst caves, and the safe thickness of the top slab of the karst cave at the roadbed base, need to be calculated.

[0033] When using masonry stone pillars for support, this invention first sets up pillars inside the karst cave and then pours concrete through the pillars. Specifically, this system includes a closed surface layer located at the opening of karst 1 and pillars 14 located inside karst 1; pillars 14 are as follows... Figure 2 As shown, the support column 14 includes connecting steel bars 15 and several first positioning steel bars 13. Two first positioning steel bars 13 are located on both sides of the support column 14 respectively. Second positioning steel bars 12 are vertically connected to the first positioning steel bars 13. The second positioning steel bars 12 are parallel to the support column 14. like Figure 3 As shown, a first connecting groove 3 and a second connecting groove 2 are provided in the karst 1, and the first connecting groove 3 and the second connecting groove 2 correspond to the connecting steel bar 15 and the second positioning steel bar 12, respectively. The second connecting groove 2 is provided with a positioning structure, which includes a first positioning structure and a second positioning structure. The second positioning structure is located inside the second connecting groove 2, and the first positioning structure is located outside the second connecting groove 2. The first positioning structure and the second positioning structure are connected by a telescopic structure 7. The telescopic structure 7 makes the first positioning structure located on the opening surface of the karst 1 or the opening surface of the second connecting groove 2. The first positioning structure is provided with a first through groove for passing through the support column 14, and the second positioning steel bar 12 is provided with a second through groove. A connecting rope passes through the second through groove, and both ends of the connecting rope pass through the first through groove.

[0034] In use, the telescopic structure 7 extends, positioning the first positioning structure on the opening surface of the karst 1, as shown below. Figure 3 As shown, the crane lifts the support column and positions it above the opening of the karst 1. The operator passes one end of the connecting rope through the second through slot of the second positioning steel bar 12, and then passes both ends of the connecting rope through the first through slot. By pulling the two ends of the connecting rope, the second positioning steel bar is inserted into the first through slot on the first positioning structure.

[0035] The telescopic structure shortens, positioning the first positioning structure on the opening surface of the second connecting groove 2, such as... Figure 4 As shown, during the shortening process of the telescopic structure, the support column moves downward together, so that the connecting steel bar 15 is inserted into the first connecting groove 3 and the second positioning steel bar 12 is inserted into the second connecting groove 2.

[0036] Example 2

[0037] Based on Example 1, the first positioning structure is as follows: Figure 5 As shown, the first positioning structure includes a first positioning plate 5 and a second positioning plate 6, both of which are provided with a first through groove; an adjustment plate 8 is connected between the first positioning plate 5 and the second positioning plate 6, the adjustment plate 8 includes a first adjustment plate and a second adjustment plate connected at one end to each other, the first adjustment plate and the second adjustment plate are located on the same vertical line or in contact with each other. When the second positioning steel bar 12 is inserted into the first through slot, the first positioning steel bar 13 acts on the first positioning plate 5, pressing the first positioning plate 5 downwards under the weight of the support column. The connection between the first adjusting plate and the second adjusting plate rotates, changing the first adjusting plate from a vertical state to a horizontal state. Figure 6 As shown, the first adjusting plate and the second adjusting plate are in contact with each other.

[0038] Several spring rods are connected between the first positioning plate 5 and the second positioning plate 6. The spring rods can further buffer the force between the first positioning plate 5 and the second positioning plate 6 to prevent the force from being too large when the support is inserted.

[0039] Example 3

[0040] Based on the above embodiments, the second positioning structure includes a third positioning plate 4 located within the second connecting groove 2. The third positioning plate 4 has a third through groove, and the inner diameter of the second positioning steel bar 12 within the second connecting groove 2 gradually decreases from top to bottom. The third positioning plate 4 has several positioning blocks 9, which contact the sides of the second positioning steel bar 12. A clamping plate 10 is provided at the opening of the second connecting groove 2, and a fixing plate is provided within the karst 1. A sliding groove 11 is provided on the fixing plate, and the clamping plate 10 and the sliding groove 11 are connected by a connecting rod, allowing the clamping plate to slide on the sliding groove.

[0041] The structure of the second positioning steel bar 12 is as follows: Figure 7 As shown, the second positioning steel bar 12 is provided with a slot 121. When the lower end of the second positioning steel bar 12 is inserted into the second connecting groove 2, the card plate 10 corresponds to the slot 121 and the card plate 10 is inserted into the slot 121.

[0042] In use, when the second positioning steel bar 12 is not inserted into the first through slot, the first positioning structure and the second positioning structure are as follows: Figure 8 As shown, when the second positioning steel bar is inserted into the first through groove, and the first positioning steel bar 13 acts on the first positioning plate 5, the first positioning plate 5 and the second positioning plate 6 come into contact with each other. At the same time, the telescopic structure shortens, moving the first positioning plate 5 and the second positioning plate 6 to the opening surface of the second connecting groove 2, as shown. Figure 9 As shown, the card plate 10 slides on the slide groove 11 and is inserted into the slot 121 of the second positioning steel bar 12 to complete the fixed connection.

[0043] When the second positioning steel bar 12 is inserted into the second connecting groove 2, if Figure 10 As shown.

[0044] Example 4

[0045] Based on the above embodiments, a karst roadbed treatment process includes the following steps: Obtain the location, size, and type of karst beneath the roadbed; Clean the karst interior; Pre-install slope drainage holes in the karst formations on the road cut slopes; A retaining wall is installed at the roadbed to keep the water out of the roadbed; The caves are reinforced according to their size and type. According to the location, size and type of karst, the pre-set support column 14 is placed inside the karst, so that the second positioning steel bar 12 of the support column 14 is inserted into the corresponding second connecting groove 2, and the connecting steel bar 15 is inserted into the corresponding first connecting groove 3. Pour concrete into the support column 14.

[0046] A retaining wall is laid on support 14, and a gravel layer, a soil layer and a planting layer are laid on the retaining wall in sequence.

[0047] The support column 14 has a sandwich structure, which consists of a first hollow layer and a second hollow layer arranged sequentially from the inside out. The sandwich structure is made of expanded perlite material. Concrete is poured into the support column 14, specifically including: Simultaneously, concrete is injected into the first hollow layer and the second hollow layer. The grouting pressure in the first hollow layer gradually increases from a preset initial pressure until it reaches a preset final grouting pressure. The grouting pressure in the second hollow layer gradually increases from a preset initial pressure until it reaches a preset final grouting pressure. The grouting pressure in the first hollow layer is greater than that in the second hollow layer.

[0048] During grouting, the grout concentration should be initially diluted and gradually increased. After grouting begins, the pump's suction volume and pressure should be monitored regularly, and various phenomena occurring during the grouting process should be recorded. Raw data should be collected, and the grouting volume and concentration should be adjusted promptly according to the actual situation. If a large amount of grout leaks from surface fissures during the grouting process, intermittent grouting should be adopted, or the pump flow rate should be reduced, and measures should be taken to fill the surface fissures to prevent the large-scale loss of grout from the ground.

[0049] During grouting, avoid injecting a large amount of cement grout in a short period of time. When the grouting volume is large, intermittent grouting and thick grout construction should be adopted in time, or a funnel-shaped sand feeder should be added to the hole opening to carry sand or stone chips into the hole with grout.

[0050] In some embodiments, the location of karst includes karst in water-developed areas, karst on road cut slopes, and karst caves in the foundation of roadbeds or retaining walls; the type of karst includes exposed karst, shallow karst, and unexposed karst; the size of karst includes deep and small karst caves, and karst caves with small diameters.

[0051] In some embodiments, the method for treating karst caves is first obtained by determining the location, size, and type of the karst beneath the roadbed; for karst located in water-developed areas, shallow karst caves and fissure karst of smaller scale are supported by masonry stone pillars.

[0052] After the pillars are placed in the karst cave, concrete is simultaneously poured into the first and second hollow layers. The concrete carries sand or gravel into the first and second hollow layers.

[0053] During the injection process, the size of the stone chips in the first hollow layer is smaller than that in the second hollow layer. Therefore, after pouring, the density of the first hollow layer is higher than that of the second hollow layer, which improves the support effect.

[0054] Furthermore, the grouting pressure in the first hollow layer is greater than that in the second hollow layer. During grouting, smaller stone chips diffuse into the larger stone chips in the second hollow layer, further improving the tightness of the transition between the first and second hollow layers and enhancing stability.

[0055] Example 5

[0056] Based on the above embodiments, when the karst type is exposed karst, such as Figure 11 As shown.

[0057] Divert water from karst caves; for karst springs or gushing caves on road cut slopes, construct drainage ditches or pipes to divert water to side ditches or platform interception ditches; for karst springs or gushing caves at the roadbed base, construct blind ditches or culverts to drain water.

[0058] For karst caves, bridges and culverts should be used to cross them; for underground rivers, sinkholes, drainage pits, karst springs, etc. with large flow rates in or near the roadbed, bridges and culverts should be used; for smaller karst caves, reinforced concrete slabs should be used to cross them, or retaining walls and toe protection should be installed to keep the water outside the roadbed. When a karst cave is located in or near the roadbed, the safe thickness of the cave roof slab and the safe distance from the roadbed must be calculated.

[0059] Reinforce the cave: (1) When it is inconvenient to reinforce the cave inside a deep and small cave, stone cover or reinforced concrete cover should be used for reinforcement. If it is close to the side ditch, the leakage of water from the side ditch should also be prevented.

[0060] (2) For karst caves with small diameter, thin roof or broken rock layers, the roof slab is blasted and backfilled with rubble for reinforcement; if the karst cave is deep or drainage needs to be maintained, arch culverts or slab culverts are used to cross it.

[0061] (3) For surface subsidence (soil cavities) within the roadbed area, if the bedrock is not exposed, backfill and compact with rubble; if the bedrock is exposed and the cavity entrance is visible, block the entrance with large stones and then backfill the soil cavity with rubble.

[0062] (4) For karst caves with a deep burial depth and a small top plate safety thickness, when the karst cave is a small karst cave filled with soil, the drilling and grouting method can be used for treatment.

[0063] (5) When the roof of the cave is thin and the cave spans a large area or there is water flow inside the cave, and when construction personnel and machinery enter the construction site, masonry rubble supports can be used for support.

[0064] Blocking the cave: (1) For karst caves on the slope of road cuts, if they affect the stability of the slope, the cave should be filled with rubble or hard rock chips, and the cave entrance should be sealed with mortar-laid rubble.

[0065] (2) For dry karst caves located at the base of roadbed or retaining wall, when the cave opening is small and the depth is shallow, backfill and compact with boulders or blocks; when the cave opening is wide and the depth is large, use bridges or culverts to cross it; when the top slab of the dry karst cave is too thin or the rock layer is too broken, it can be blasted and then backfilled or a bridge or culvert can be used to cross it.

[0066] Example 6

[0067] Based on the above embodiments, when the karst location is shallow karst, the treatment process is as follows: Figure 12 As shown.

[0068] For surface dry karst caves (top thickness less than 2m) that are hidden under excavated or filled roadbeds, the open-cut method can be used to remove the thin karst top slab and then fill the roadbed according to the requirements of the rockfill road regulations.

[0069] For shallow dry karst caves that are hidden under excavated or filled roadbeds and affect the stability of the roadbed: when the karst cave is a small, filled karst cave, the drilling and grouting method can be used for treatment.

[0070] For dry karst caves with a ceiling depth greater than 10m and a diameter less than 5m, no treatment is required if the karst ceiling is relatively intact.

[0071] In the calculation of the safe distance between the toe of the roadbed slope and nearby karst caves, and the safe thickness of the top slab of the karst caves at the roadbed base: Calculation of the safe thickness of the top slab of the karst cave in the roadbed foundation; (1) The top slab of the karst cave in the subgrade foundation is intact, and the safe thickness is calculated according to the bending formula of a fixed beam:

[0072] In the formula, H is the safe thickness of the top plate (m). B is the width of the embankment bottom (m); [6] is the flexural strength of the rock mass (kPa), and M is the bending moment (kN·m).

[0073] Calculation of the fixed beams connecting the two walls. ; In the formula, Q is the total load on the top of the cave (including its own weight and additional load) (kN / m); B is the length of the cave along the route (m); K is the safety factor, which is taken as >1.20 for limestone.

[0074] (2) For rock strata adapted to the weathering and fracturing of the cave roof, the estimation is based on the concept of a fractured arch:

[0075] In the formula, H is the height of the fractured arch, H0 is the height of the cave (m); b is the radius of the cave; φ is the internal friction angle of the rock (·); and f is the strength coefficient of the rock. The safe thickness of the cave roof = (height of the fractured arch + height required for the upper load) * safety factor.

[0076] Calculation of the safe distance between the roadbed and nearby karst caves; The safe distance between the toe of the roadbed slope and nearby karst caves is calculated based on the diffusion angle at the time of collapse.

[0077] In the formula, H is the thickness of the cave roof (m); β is the collapse diffusion angle (degrees);

[0078] In the formula, φ is the internal friction angle of the rock (degrees); K is the safety factor, which is taken as 1.10~1.25 (the maximum value is taken for highways). If there is a cover layer on the top rock layer, draw an oblique line from the bottom of the soil layer upward at a 45' angle to find the intersection point with the ground. The toe of the roadbed slope should be outside the intersection point.

[0079] The terms "first," "second," and "third" used in this document are merely for clarity of description and are not intended to restrict any order or emphasize importance. Furthermore, the term "connection" used in this document, unless otherwise specified, can refer to a direct connection or an indirect connection via other components.

[0080] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A karst roadbed treatment system, characterized in that, It includes a closed surface layer located at the opening of the karst (1) and a support column (14) located inside the karst (1); the support column (14) includes connecting steel bars (15) and several first positioning steel bars (13), two first positioning steel bars (13) are located on both sides of the support column (14), and a second positioning steel bar (12) is vertically connected to the first positioning steel bar (13), and the second positioning steel bar (12) is parallel to the support column (14); A first connecting groove (3) and a second connecting groove (2) are provided in the karst (1), and the first connecting groove (3) and the second connecting groove (2) correspond to the connecting steel bar (15) and the second positioning steel bar (12) respectively; The second connecting groove (2) is provided with a positioning structure, which includes a first positioning structure and a second positioning structure. The second positioning structure is located inside the second connecting groove (2), and the first positioning structure is located outside the second connecting groove (2). The first positioning structure and the second positioning structure are connected by a telescopic structure (7). The telescopic structure (7) makes the first positioning structure located on the opening surface of the karst (1) or on the opening surface of the second connecting groove (2). The first positioning structure is provided with a first through groove for the second positioning steel bar (12) to pass through, the second positioning steel bar (12) is provided with a second through groove, a connecting rope passes through the second through groove, and both ends of the connecting rope pass through the first through groove; the first positioning structure includes a first positioning plate (5) and a second positioning plate (6), both the first positioning plate (5) and the second positioning plate (6) are provided with a first through groove; an adjustment plate (8) is connected between the first positioning plate (5) and the second positioning plate (6), the adjustment plate (8) includes a first adjustment plate and a second adjustment plate connected at one end to each other, the first adjustment plate and the second adjustment plate are located on the same vertical line or in contact with each other; In the original state, the first adjusting plate and the second adjusting plate are located on the same vertical line; when the two ends of the connecting rope pass through the first through groove and drive the second positioning steel bar (12) to insert into the first through groove, the first positioning steel bar (13) drives the first positioning plate (5) and the second positioning plate (6) to contact each other, and the first adjusting plate and the second adjusting plate contact each other.

2. The karst roadbed treatment system according to claim 1, characterized in that, The second positioning structure includes a third positioning plate (4) located in the second connecting groove (2), and a third through groove is provided on the third positioning plate (4). The inner diameter of the second positioning steel bar (12) in the second connecting groove (2) gradually decreases from top to bottom. The third positioning plate (4) is provided with several positioning blocks (9), and the positioning blocks (9) are in contact with the side of the second positioning steel bar (12).

3. The karst roadbed treatment system according to claim 1, characterized in that, A card plate (10) is provided at the opening of the second connecting groove (2), and a slot (121) is provided on the second positioning steel bar (12). When the lower end of the second positioning steel bar (12) is inserted into the second connecting groove (2), the card plate (10) corresponds to the slot (121), and the card plate (10) is inserted into the slot (121).

4. The karst roadbed treatment system according to claim 1, characterized in that, The support column (14) has a mezzanine layer, which has a first hollow layer and a second hollow layer arranged sequentially from the inside to the outside.

5. A karst roadbed treatment system according to claim 4, characterized in that, The interlayer is made of expanded perlite.

6. A karst roadbed treatment process, characterized in that, The processing system comprising any one of claims 1-5 includes the following steps: Obtain the location, size, and type of karst beneath the roadbed; Clean the karst interior; Pre-install slope drainage holes in the karst formations on the road cut slopes; A retaining wall is installed at the roadbed to keep the water out of the roadbed; The caves are reinforced according to their size and type. According to the location, size and type of karst, the pre-set support (14) is placed inside the karst, so that the second positioning steel bar (12) of the support (14) is inserted into the corresponding second connecting groove (2), and the connecting steel bar (15) is inserted into the corresponding first connecting groove (3); Concrete was poured into the support column (14).

7. The karst roadbed treatment process according to claim 6, characterized in that, A baffle is laid on the support (14), and a gravel layer, a soil layer and a planting layer are laid on the baffle in sequence.

8. The karst roadbed treatment process according to claim 6, characterized in that, The support column (14) is provided with a sandwich layer, which consists of a first hollow layer and a second hollow layer arranged sequentially from the inside to the outside. The sandwich layer is made of expanded perlite material. The concrete is poured into the support column (14), specifically including: Concrete is injected into the first hollow layer and the second hollow layer at the same time. The grouting pressure in the first hollow layer gradually increases from the preset first initial pressure until the preset first final grouting pressure is reached. The grouting pressure in the second hollow layer gradually increases from the preset second initial pressure until it reaches the preset second final grouting pressure.

9. A karst roadbed treatment process according to claim 8, characterized in that, The grouting pressure in the first hollow layer is greater than that in the second hollow layer.

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