Slope landslide protection structure for a quicksand layer open-pit mine

Abstract

The application discloses a kind of quicksand layer open-pit mine slope landslide protection structures, including first fiber concrete layer, drainage ditch, dry channel, shallow grouting hole and second fiber concrete layer, first fiber concrete layer is sprayed in bottom slope surface;Drainage ditch is set on the slope bottom surface and extends along the length direction of slope;Dry channel outer end is extended to bottom slope surface and is connected with drainage ditch, and its inner end extends to bottom slope interior and is connected with underground water;Shallow grouting hole is filled with cement slurry, and cement slurry can permeate to bottom slope interior to fill the quicksand layer pore after dry underground water;Second fiber concrete layer is sprayed on the surface of first fiber concrete layer.Avoid to treat entire quicksand layer, greatly save the amount of work and construction period, construction is simple, construction cost is low, economy is good, also avoid groundwater erosion, soften sand layer, improve the self-stability of quicksand layer, especially the stability of upper slope.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of flow sand layer open-pit mine slope landslide protection structure. BACKGROUND

[0002] The slope stability in the process of open-pit mining directly affects the safety production and economy of the mine. The engineering geological properties and hydrogeological properties of rock mass are one of the main factors affecting the slope stability. Flow sand layer is a special geological body affected by the coupling of engineering geology and hydrogeology under the condition of thick sand layer and water enrichment. Its engineering geological and hydrogeological conditions are relatively complex. Direct exposure can easily cause collapse, even bury the mining platform. Currently, when exposing flow sand layer in open-pit slope, methods such as replacement and retaining wall support are often used to ensure the stability of the slope and avoid safety accidents. However, the above methods have high treatment cost and low efficiency.

[0003] For example, Chinese patent application No. 202221459150.5, entitled "Slope support structure for deep foundation pit containing flow sand layer", discloses a slope support structure for deep foundation pit containing flow sand layer. The first retaining wall includes first concrete pipes arranged along the outer periphery of the foundation pit. The second retaining wall is located inside the first retaining arm and includes second concrete pipes arranged at intervals. The third retaining wall is located between the first retaining arm and the second retaining wall and includes wooden stakes arranged at intervals. The base layer is located at the bottom of the foundation pit. The fourth retaining wall is located on the base layer and includes a brick masonry located inside the second retaining arm. Although it can prevent the collapse of the soil around the foundation pit and reduce the amount of excavated soil, the structure has high support cost. Meanwhile, the exposed area of the open-pit slope is large, and the use of this structure is not conducive to construction.

[0004] Alternatively, for example, Chinese patent application No. 201710451292.4, entitled "Method for supporting slope of foundation pit containing flow sand layer using composite soil nailing wall", discloses a method for supporting slope of foundation pit containing flow sand layer. The method includes constructing a waterproof curtain, excavating the foundation pit in layers, measuring and marking the hole position and drilling the hole along the slope of the foundation pit, installing a positioning bracket, inserting a soil nailing steel into the grouting hole, and filling the hole with grout according to the orientation of the hole mouth. A steel mesh is fixed, and a concrete surface layer is formed by spraying concrete. Although it can avoid the settlement of buildings near the foundation pit, it is not suitable for open-pit mines because a large amount of flow sand layer needs to be exposed in open-pit mines, resulting in the need for support for all exposed steps. The support cost is high, the construction difficulty is great, and the economy is not good.

[0005] It is necessary to design a protection structure that is not only suitable for the slope of open-pit mines, but also an economical, fast and efficient protection structure for flow sand layer slope landslide. SUMMARY

[0006] The present application provides a kind of quicksand layer open-pit mine slope landslide protection structure, it overcomes the insufficient of background art.The technical scheme that the present application adopts to solve its technical problems is one of:

[0007] A kind of quicksand layer open-pit mine slope landslide protection structure, the protection structure includes:

[0008] First fiber concrete layer, it is sprayed in the bottom slope surface;

[0009] Drainage ditch, it is set on the slope bottom surface and extends along the length direction of slope;

[0010] For reducing the initial underground water level in quicksand, the dry channel of underground water, the outer end of the dry channel extends to the bottom slope surface and is connected with drainage ditch, and the inner end extends to the inside of the bottom slope and is connected with underground water;

[0011] Shallow grouting hole, which is perpendicular to the bottom slope surface and located above the dry channel, is filled with cement slurry, and the cement slurry can penetrate into the inside of the bottom slope to fill the quicksand pore after the dry underground water;

[0012] Second fiber concrete layer, it is sprayed in the surface of first fiber concrete layer.

[0013] In a preferred embodiment: the dry channel includes dry hole and filter pipe, the filter pipe is provided with a plurality of filter holes and its outer periphery is wrapped with geotextile, the filter pipe is inserted into the dry hole and its outer end is the outer end of the dry channel.

[0014] In a preferred embodiment: the dry hole is provided with at least one row, each row of dry holes includes a plurality of horizontally spaced dry holes, the distance between the dry hole and the slope bottom surface is 0.3-0.7 meters, and the dry hole depth is 20-40 meters.

[0015] In a preferred embodiment: the distance between the dry hole and the slope bottom surface is 0.5 meters, and the dry hole depth is 30 meters.

[0016] In a preferred embodiment: the thickness of the first fiber concrete layer and the second fiber concrete layer is 8-12 millimeters.

[0017] In a preferred embodiment: the thickness of the first fiber concrete layer and the second fiber concrete layer is 10 millimeters.

[0018] In a preferred embodiment, the shallow grouting holes are arranged in multiple rows and are spaced apart vertically, each row of the shallow grouting holes comprises multiple spaced-apart shallow grouting holes, the row spacing of the shallow grouting holes is 1-3 meters, the hole spacing is 1-3 meters, the distance between the lowermost row of the shallow grouting holes and the slope bottom surface is 1-2 meters, and the distance between the uppermost row of the shallow grouting holes and the top end of the bottom slope is 1-2 meters.

[0019] In a preferred embodiment, the row spacing of the shallow grouting holes is 2 meters, the hole spacing is 2 meters, the distance between the lowermost row of the shallow grouting holes and the slope bottom surface is 1.5 meters, and the distance between the uppermost row of the shallow grouting holes and the top end of the bottom slope is 1.5 meters.

[0020] The second technical solution adopted by the present application to solve the technical problem is:

[0021] A method for protecting a flow sand layer open-pit mine slope landslide, comprising:

[0022] Step 10, spraying a first fiber concrete layer on the surface of the bottom slope to seal and temporarily stabilize the surface of the slope;

[0023] Step 20, constructing a drainage ditch on the slope bottom surface to extend along the length direction of the slope;

[0024] Step 30, constructing a dewatering hole at the bottom slope, which extends from the surface of the bottom slope to the inside of the bottom slope to communicate with the underground water;

[0025] Step 40, arranging filter holes on the filter pipe and winding geotextile around the outer periphery of the filter pipe, then inserting the filter pipe wrapped with the geotextile into the dewatering hole and reserving a section extending out of the surface of the bottom slope, which corresponds to the drainage ditch to form a dewatering channel that can reduce the initial underground water level in the flow sand layer to the dewatered underground water level;

[0026] Step 50, constructing shallow grouting holes above the dewatering hole and grouting cement slurry into the shallow grouting holes, which can permeate into the inside of the bottom slope to fill the pores of the flow sand layer after the dewatered underground water;

[0027] Step 60, spraying a second fiber concrete layer on the first fiber concrete layer to completely seal the surface of the slope.

[0028] In a preferred embodiment, in step 50, the shallow grouting holes are arranged in multiple rows and are spaced apart vertically, and during grouting, the uppermost row of the shallow grouting holes and the lowermost row of the shallow grouting holes are grouted first, and then the intermediate shallow grouting holes are grouted.

[0029] Compared with the background art, the present technical solution has the following advantages:

[0030] Through the dewatering channel and the drainage ditch, the groundwater level can be greatly reduced, only the bottom slope of the quicksand layer needs to be protected, the whole quicksand layer does not need to be treated, the engineering quantity and the construction period are greatly saved, the construction is simple, the construction cost is low, the economy is good, the groundwater erosion and the softening of the sand layer are avoided, the self-stability of the quicksand layer is improved, especially the stability of the upper slope; meanwhile, on the basis of dewatering the groundwater, the shallow grouting hole is constructed, the shallow part of the bottom slope is grouted, the pores in the quicksand layer are filled, the quicksand layer of the bottom slope is reinforced, the physical and mechanical properties of the bottom quicksand layer are further improved, the purpose of maintaining the stability of the whole slope is achieved; the two layers of fiber concrete layers are sprayed on the surface of the bottom slope, the stability of the slope is not affected by the erosion and damage of the slope caused by the rainfall and other natural factors. BRIEF DESCRIPTION OF DRAWINGS

[0031] The application will be further described below in combination with the drawings and examples.

[0032] Figure 1 A flowchart of a quicksand layer open-pit mine slope landslide protection structure of a preferred embodiment is shown.

[0033] Figure 2 A sectional view of a quicksand layer open-pit mine slope landslide protection structure of a preferred embodiment is shown.

[0034] Figure 3 A plan view of a quicksand layer open-pit mine slope landslide protection structure of a preferred embodiment is shown.

[0035] Figure 4 A structural view of a filter pipe of a preferred embodiment is shown.

[0036] Figure 5 A structural view of a grouting pipe of a preferred embodiment is shown.

[0037] Figure 6 A state view of a grouting hole grouting of a preferred embodiment is shown. DETAILED DESCRIPTION

[0038] In the claim, the specification and the above drawings of the application, unless otherwise explicitly limited, the terms such as "first", "second" or "third" are used to distinguish different objects, and are not used to describe a specific order.

[0039] In the claims, the specification, and the drawings of the present application, terms such as "center", "transverse", "longitudinal", "horizontal", "vertical", "top", "bottom", "inner", "outer", "upper", "lower", "front", "rear", "left", "right", "clockwise", "counterclockwise", and the like are used as terms of reference and are not intended to limit the present application to any particular position or orientation of the described device or element. Therefore, these terms are used merely to simplify the description of the present application and are not intended to limit the specific scope of the present application.

[0040] In the claims, the specification, and the drawings of the present application, unless otherwise expressly specified, the terms "fixedly connected", "fixedly connected" are to be interpreted broadly, i.e. any connection mode between the two without displacement relationship and relative rotation relationship, that is to say, it includes non-detachable fixed connection, detachable fixed connection, integration and fixed connection through other devices or elements.

[0041] In the claims, the specification, and the drawings of the present application, the terms "including", "having", and their variants are intended to mean "including but not limited to".

[0042] Please refer to Figures 1 to 6 A preferred embodiment of a flow sand layer open-pit mine slope landslide protection structure, the flow sand layer open-pit mine slope landslide protection structure comprises a first fiber concrete layer 1, a drainage ditch 4, a drainage channel, a shallow grouting hole 3, and a second fiber concrete layer.

[0043] The flow sand layer open-pit mine slope in the embodiment is provided with a plurality of steps. The slope surface between the two step surfaces at the bottom is the bottom slope surface. The flow sand layer open-pit mine slope can also not be provided with steps, without being limited thereto.

[0044] The first fiber concrete layer 1 is sprayed on the bottom slope surface.

[0045] In the embodiment, the first fiber concrete layer 1 is C25 fiber concrete, wherein the fiber diameter is 0.4 mm, the length is 20 mm, and the mixing amount is 4% of the weight of the mixed amount. Moreover, the thickness of the first fiber concrete layer 1 is 8-12 mm. Preferably, the thickness of the first fiber concrete layer 1 is 10 mm, which produces better slope stability.

[0046] The drainage ditch 4 is arranged on the slope bottom surface and extends along the length direction of the slope.

[0047] In this embodiment, the drainage ditch 4 is arranged at a distance of 0.5 meters from the surface of the bottom slope, and has a size of 1.0 m x 0.5 m and a slope of 3 ‰.

[0048] The dewatering channel is used to lower the initial underground water level 14 in the quicksand layer, and has an outer end portion extending outwardly beyond the surface of the bottom slope and connected to the drainage ditch 4, and an inner end portion extending inwardly into the bottom slope to be connected to the underground water.

[0049] In this embodiment, the dewatering channel includes the dewatering holes 2 and the water filtering pipe 10, the water filtering pipe 10 is provided with a plurality of water filtering holes and has a geotextile 13 wound thereon, and the water filtering pipe 10 is inserted into the dewatering holes 2 and has the outer end portion as the outer end portion of the dewatering channel.

[0050] In this embodiment, the dewatering holes 2 are arranged in at least one row, each row of the dewatering holes 2 includes a plurality of dewatering holes 2 arranged horizontally and at intervals, the distance between the dewatering holes 2 and the surface of the slope bottom is 0.3-0.7 meters, and the depth of the dewatering holes 2 is 20-40 meters. Preferably, the distance between the dewatering holes 2 and the surface of the slope bottom is 0.5 meters, and the depth of the dewatering holes 2 is 30 meters.

[0051] In this embodiment, the diameter of each dewatering hole 2 is φ 108 mm, the hole spacing is 4 meters, and the upward inclination angle is 3°. The water filtering pipe 10 is made of a PVC pipe with a diameter of 79 mm, and the water filtering holes with a diameter of 10 mm and a hole spacing of 200 mm are formed on the PVC pipe in a whole, and then the geotextile is wound thereon. When the water filtering pipe 10 is inserted into the dewatering holes 2, the outer end portion thereof extends outwardly by 1 meter, so as to facilitate the underground water to be introduced into the drainage ditch.

[0052] The shallow grouting hole 3 is perpendicular to the surface of the bottom slope and located above the dewatering channel, and is filled with cement grout, and the cement grout can permeate into the bottom slope to fill the pore of the quicksand layer after the underground water is dewatered.

[0053] In this embodiment, the shallow grouting holes 3 are arranged in multiple rows and at intervals in the vertical direction, each row of the shallow grouting holes 3 includes a plurality of shallow grouting holes 3 arranged at intervals, the row spacing of the shallow grouting holes 3 is 1-3 meters, the hole spacing of the shallow grouting holes 3 is 1-3 meters, the distance between the lowermost row of the shallow grouting holes 3 and the surface of the slope bottom is 1-2 meters, and the distance between the uppermost row of the shallow grouting holes 3 and the top end of the bottom slope is 1-2 meters. Preferably, the row spacing of the shallow grouting holes 3 is 2 meters, the hole spacing of the shallow grouting holes 3 is 2 meters, the distance between the lowermost row of the shallow grouting holes 3 and the surface of the slope bottom is 1.5 meters, and the distance between the uppermost row of the shallow grouting holes 3 and the top end of the bottom slope is 1.5 meters.

[0054] In this embodiment, the diameter of the shallow grouting hole 3 is 40 mm, and the depth thereof is 3 meters.

[0055] In order to grout, in this embodiment,Figure 6 As shown, the protection structure is further provided with a grouting system, which comprises a stirring barrel 7, a grouting pipe 6, a grouting pump 5, a grouting pipe 12 and a grouting flower pipe 11. The grouting flower pipe 11 has a diameter of 35 mm, is punched into the shallow grouting hole 3 by a drilling machine, and has an outer end exposed by 0.5 m, which is convenient for being connected with the grouting pipe 12, and then the grouting pump 5, the grouting pipe 6 and the stirring barrel 7 are connected in sequence.

[0056] In the embodiment, the grouting slurry 8 is pure cement slurry, the water-cement ratio is 1:3, the stirring time is less than 10 minutes, and the grouting rate is not greater than 30 L / min.

[0057] The second fiber concrete layer (not shown in the figure) is sprayed on the surface of the first fiber concrete layer 1.

[0058] In the embodiment, the thickness of the second fiber concrete layer is 8-12 mm. Preferably, the thickness of the second fiber concrete layer is 10 mm.

[0059] In the embodiment, the material of the second fiber concrete layer is the same as that of the first fiber concrete layer 1.

[0060] A method for protecting the slope landslide of a quicksand open-pit mine, which comprises:

[0061] Step 10: spraying a first fiber concrete layer 1 on the surface of the bottom slope to seal and temporarily stabilize the surface of the slope; in the embodiment, the first fiber concrete layer 1 is C25 fiber concrete, in which the fiber has a diameter of 0.4 mm, a length of 20 mm, and a mixing amount of 4% of the weight of the mixture, and the thickness of the first fiber concrete layer is 10 mm.

[0062] Step 20: constructing a drainage ditch 4 on the slope bottom surface to form a drainage ditch 4 extending along the length direction of the slope; in the embodiment, the drainage ditch 4 is arranged at a distance of 0.5 m from the surface of the bottom slope, has a size of 1.0 m×0.5 m, and has a slope of 3 ‰.

[0063] Step 30: constructing a dewatering hole 2 at the bottom slope, which extends from the surface of the bottom slope to the inside of the bottom slope to be connected with underground water; in the embodiment, the dewatering holes 2 are arranged in one row and are arranged at a distance of 0.5 m from the slope bottom surface, each dewatering hole 2 has a hole depth of 30 m, a hole diameter of φ108 mm, and a hole distance of 4 m, and has an upward angle of 3°.

[0064] Step 40, setting filter holes on the filter pipe 10, winding geotextile 13 on the outer periphery of the filter pipe 10, inserting the filter pipe 10 wrapped with geotextile 13 into the dewatering hole 2, and reserving a section extending out of the bottom slope surface, which corresponds to the drainage ditch 4, to form a dewatering channel, which can reduce the initial underground water level 14 in the quicksand layer to the dewatered underground water level 15; in this embodiment, the filter holes with a hole diameter of 10 mm and a hole spacing of 200 mm are first set on the PVC pipe, and then the geotextile 13 is wound; when the filter pipe 10 is inserted into the dewatering hole 2, the outer end thereof extends outward by 1 m and corresponds to the drainage ditch 4.

[0065] Step 50, constructing the shallow grouting hole 3 above the dewatering hole 2 and pouring cement slurry into the shallow grouting hole 3, which can permeate into the bottom slope to fill the pore of the quicksand layer after the dewatered underground water;

[0066] In this embodiment, as shown in Figure 3 , the shallow grouting hole 3 is provided with 6 rows, the row spacing is 2 m, the hole spacing is 2 m, the distance between the lowermost row of shallow grouting holes 3 and the slope bottom surface is 1.5 m, and the distance between the uppermost row of shallow grouting holes 3 and the top end of the bottom slope is 1.5 m. Moreover, the hole diameter of each shallow grouting hole 3 is 40 mm, and the hole depth is 3 m.

[0067] The grouting flower pipe 11 with a diameter of 35 mm is punched into the shallow grouting hole 3 by a drilling machine, and the outer end of the grouting flower pipe 22 is exposed by 0.5 m, and then the grouting pipe 12, the grouting pump 5, the slurry conveying pipe 6 and the stirring barrel 7 are connected in sequence. During grouting, the uppermost row of shallow grouting holes 3 and the lowermost row of shallow grouting holes 3 are grouted first, and then the intermediate shallow grouting holes 3 are grouted, so as to fill the pores in the quicksand layer, reinforce the quicksand layer of the bottom slope, further improve the physical and mechanical properties of the bottom quicksand layer, and achieve the purpose of maintaining the stability of the overall slope.

[0068] Step 60, spraying a second fiber reinforced concrete layer on the first fiber reinforced concrete layer 1 to completely seal the slope surface.

[0069] The above description is only a preferred embodiment of the present application, and therefore cannot limit the scope of the present application, that is, equivalent changes and modifications made according to the scope and content of the present patent should still be within the scope of the present application.

Claims

1. A flow sand layer open-pit mine slope landslide protection structure, characterized in that: The protection structure comprises: a first fiber concrete layer sprayed on the surface of the bottom slope; a drainage ditch arranged on the bottom surface of the slope and extending along the length direction of the slope; a drainage channel for lowering the initial underground water level in the quicksand layer, the outer end of the drainage channel extending out of the surface of the bottom slope and being connected with the drainage ditch, and the inner end of the drainage channel extending to the inside of the bottom slope and being connected with the underground water; a shallow grouting hole arranged perpendicularly to the surface of the bottom slope and above the drainage channel, the shallow grouting hole being filled with cement grout, and the cement grout penetrating into the inside of the bottom slope to fill the pores of the quicksand layer after the underground water is drained; a second fiber concrete layer sprayed on the surface of the first fiber concrete layer; the drainage channel comprises a drainage hole and a filter pipe, the filter pipe being provided with a plurality of filter holes and being wrapped with geotextile around the outer periphery, the filter pipe being inserted into the drainage hole, and the outer end of the filter pipe being the outer end of the drainage channel; the drainage holes are arranged in at least one row, each row of the drainage holes comprises a plurality of horizontally spaced drainage holes, the distance between the drainage holes and the bottom surface of the slope is 0.3-0.7 meters, and the depth of the drainage holes is 20-40 meters; the shallow grouting holes are arranged in a plurality of rows and are spaced vertically, each row of the shallow grouting holes comprises a plurality of vertically spaced shallow grouting holes, the row distance of the shallow grouting holes is 1-3 meters, the hole distance of the shallow grouting holes is 1-3 meters, the distance between the lowermost row of the shallow grouting holes and the bottom surface of the slope is 1-2 meters, and the distance between the uppermost row of the shallow grouting holes and the top end of the bottom slope is 1-2 meters.

2. The flow sand layer open-pit mine slope landslide protection structure according to claim 1, characterized in that: the distance between the drainage holes and the bottom surface of the slope is 0.5 meters, and the depth of the drainage holes is 30 meters.

3. The flow sand layer open-pit mine slope landslide protection structure according to claim 1, characterized in that: the thickness of the first fiber concrete layer and the second fiber concrete layer is 8-12 millimeters.

4. The flow sand layer open-pit mine slope landslide protection structure according to claim 3, characterized in that: the thickness of the first fiber concrete layer and the second fiber concrete layer is 10 millimeters.

5. The flow sand layer open-pit mine slope landslide protection structure according to claim 1, characterized in that: the row distance of the shallow grouting holes is 2 meters, the hole distance of the shallow grouting holes is 2 meters, the distance between the lowermost row of the shallow grouting holes and the bottom surface of the slope is 1.5 meters, and the distance between the uppermost row of the shallow grouting holes and the top end of the bottom slope is 1.5 meters.

6. A method for preventing slope landslide of a quicksand layer open-pit mine, which applies the slope landslide prevention structure of any one of claims 1 to 5, characterized in that: comprises: step 10, spraying a first fiber concrete layer on the surface of the bottom slope to seal and temporarily stabilize the surface of the slope; step 20, constructing a drainage ditch on the bottom surface of the slope to form a drainage ditch extending along the length direction of the slope; step 30, constructing a drainage hole at the bottom slope, the drainage hole extending from the surface of the bottom slope to the inside of the bottom slope and being connected with the underground water; step 40, arranging filter holes on the filter pipe, wrapping geotextile around the outer periphery of the filter pipe, inserting the filter pipe wrapped with the geotextile into the drainage hole, and reserving a section extending out of the surface of the bottom slope, the reserved section corresponding to the drainage ditch to form a drainage channel, the drainage channel lowering the initial underground water level in the quicksand layer to the underground water level after the underground water is drained; step 50, constructing a shallow grouting hole above the drainage hole, and filling the shallow grouting hole with cement grout, the cement grout penetrating into the inside of the bottom slope to fill the pores of the quicksand layer after the underground water is drained; step 60, spraying a second fiber concrete layer on the first fiber concrete layer to completely seal the surface of the slope.

7. A method of preventing slope failure in a sand-wash open pit according to claim 6, characterized in that: In step 50, the shallow grouting holes are arranged in multiple rows and are arranged at intervals up and down. When grouting, the shallow grouting holes at the uppermost row and the shallow grouting holes at the lowermost row are grouted first, and then the shallow grouting holes in the middle are grouted.

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