CN111236274A - Process improvement of engineering mining method for strip mine slope structure and reclamation mode - Google Patents

Abstract

Thoroughly transforming the traditional side slope structure and reclamation mode of the surface mine; the effective reclamation area of the side slope is increased from less than 20% to more than 95%, the land condition of the side slope reclamation is converted to be good in nature, the reclamation operation efficiency is converted to be safe and efficient in mechanized construction, and finally the green mining construction in the field of open mines is promoted to realize breakthrough development.

Description

Process improvement of engineering mining method for strip mine slope structure and reclamation mode

The technical field is as follows:

the application belongs to the technical field of land reclamation of open-pit mines.

Technical background:

the project mining method of certificate No. 1852716 (patent No. 2013101302502) proposes a new concept and a new process that enables a legacy structure and a gob after a mine is closed to be recycled by prior design and production control, but does not propose a feasible technical scheme for how a surface mine reforms a conventional excavation structure and realizes slope reclamation and ecological reconstruction; for many years, the traditional mining technology and the specifications and regulations derived from the traditional mining technology have the main and only technical idea of resource mining and operation safety, and the mining mode of the strip mine slope engineering is regulated according to the main technical idea, such as: the height of the step is not more than 15 meters, the slope angle is 60-70 degrees, the width of the safety step is 3-4 meters, the step is cleaned for 4-5 meters, and the integral slope angle meets the stability safety factor, … and the like; however, the traditional side slope structure mode cannot adapt to the new trend of green mine construction and ecological sustainable development in theory or practice; the prior side slope structure mode restricts the side slope reclamation and ecological reconstruction of the surface mine; for example, parameters according to the conventional specification: the slope angle is 60-65 degrees, the width of the safety step is 3-4 meters, the height of the step is 15 meters, and the reclamation process comprises building of a retaining wall and backfilling planting; roughly estimated, the projection area of the slope surface accounts for about 70% of the whole area of the side slope, and the steeply inclined slope surface cannot be reclaimed and greened at all; removing the retaining wall and the safety distance occupied outside the wall by the remaining step platform, wherein the actual filling and reclamation area of the step is less than 20% of the whole area of the side slope; the step backfill soil has narrow and shallow foundation, so that the standing condition for forest growth is difficult to form, and the reclamation greening has a false name; the land reclamation work of strip mine side slopes across the country is caused, and the thunder Long reaches for decades, but the effect is not always achieved.

The applicant has carried out field investigation on the reclamation of the slope land of a plurality of open-pit mines in the south, and the findings are as follows: the side slope is obtrusive and bare, and a few saplings and miscanthus on high steps are like a few thin hairs on bald heads and only the door surface can be installed; with mine personnel seating, everyone talks about: the width of the platform is more than 3 meters, after the retaining wall is built, the actual backfilling soil is less than 2 meters, the backfilling soil thickness is dozens of centimeters, and the construction is very difficult; under the action of sunlight insolation and rock transpiration, the planting layer with the minimum cross section can not nourish water at all, and plants are difficult to grow normally; some design units and mines have also tested the method of planting the climbing tiger climbing plants on the steps, hope that vines climb green slope, but years of tests show that the climbing tiger vines are difficult to climb and breed on hot rock walls with little effect; the application considers that: to really solve the difficult problem of side slope land reclamation of surface mines, the traditional surface mine side slope structure mode which lasts for decades must be thoroughly reformed, and the site-setting conditions for side slope land reclamation are fundamentally built and improved, so that the real green mine ecological reconstruction can be realized.

The invention content is as follows:

for a firmer rock slope layer section, the traditional step slope angle of 60-70 degrees is increased to (or approaches to) 90 degrees, and the slope occupation is eliminated; finally, the slope is formed by cutting through a smooth blasting method, and the broken zone part is reinforced by anchor spraying; the height of the step is reduced to be below 10 meters, the width of the layering platform is increased to be above 8 meters, and the smoothness of the construction machinery is guaranteed; the backfill mode of the traditional retaining wall retaining block is cancelled, and the assembly of reinforced concrete prefabricated parts is changed, so that the occupation of a building on a reclamation site is reduced; FIG. 1 is a supporting and backfilling mode of a rock slope step, and FIG. 3 is a perspective view of the supporting and backfilling mode; assembling a retaining structure by using a retaining support 1 and a retaining plate 2, wherein the height of the retaining structure is not less than 2 m, and the distance between the retaining supports is determined by design; mortar is filled among the soil retaining bracket, the soil retaining plate and the rock foundation to prevent water leakage; slightly inclining, lifting and thickening the backfill soil from the slope edge to the slope bottom, wherein the minimum backfill thickness is preferably not less than 2 m, and finishing a wave-shaped terrace to retain rainwater; the step drainage mode is as follows: at proper intervals, a soil retaining bracket with a special drainage function of a transverse drainage hole 3 and a vertical drainage hole 4 is arranged (the rest soil retaining brackets are not provided with the drainage function), and the upper part of the vertical drainage hole 4 is covered with a permeable cover 5 and a filter body 6; rainwater flows over the wavy terrace from the bottom to the slope edge to cause sufficient infiltration and storage, and redundant surface water is filtered by the water permeable cover 5 and the filter 6 and then is drained to a next stage or the bottom of the slope through the slope water drain pipe 10 and the transverse flow dispersing pipe 9; the permeable cover 5 is made of permeable concrete pressed film and has filtering and water permeability; the filter body 6 is a reverse filter body formed by combining medium sand, coarse sand and fine stone and is used for filtering silt; the transverse flow-dispersing pipe 9 is provided with flower holes, so that the upper drain water is dispersed to two sides to reduce impact, and the upper drain water is enabled to overflow and seep down through the wavy terrace again; in fig. 1, the reinforcement anchor 8 is arranged according to the field situation; the specifications and reinforcing bars of the retaining frame 1 and the retaining plate 2 are determined by the calculation of the filling pressure.

For soil slope layer sections, in order to facilitate the installation of slope protection plates, the slope angle is preferably set to be about 80 degrees, so that the occupied area of the slope is reduced; the height of the step is reduced to below 5 meters, and the width of the platform is increased to above 6 meters; the supporting and blocking structure is assembled by reinforced concrete prefabricated parts; FIG. 2 is a supporting and backfilling mode of a soil slope step, and FIG. 4 is a perspective view of the supporting and backfilling mode; a retaining structure is assembled by the slope protection plate 11, the L-shaped cover plate 12, the hook head bracket 13 and the retaining plate 2; when the platform soil energy is suitable for planting trees, the height of the supporting and retaining structure and the soil filling thickness can be properly reduced; the distance between the hook head brackets is determined by design; mortar is filled among the slope protection plate, the L-shaped cover plate, the soil retaining plate and the hook head bracket at the top of the slope and between the slope protection plate, the L-shaped cover plate, the soil retaining plate and the hook head bracket and the base surface to prevent water leakage; slightly inclining, lifting and thickening the backfill from the slope edge to the slope bottom, and finishing a wave-shaped terrace to retain rainwater; the drainage mode of the soil step is basically the same as that of a rock step; because the soil slope surface has poor self-stability, a slope protection plate structure is additionally arranged, the bottom end of the slope protection plate is inserted into the base surface of the lower step, and the upper end of the slope protection plate is clamped and positioned by an L-shaped cover plate; the length of the L-shaped cover plate is equal to the distance between the hook head supports, and the hook heads at the outer ends of the hook head supports are hooked to position the L-shaped cover plate; the slope protection structure can also adopt an anchor net spraying mode; in fig. 2 the reinforcement anchor 8 is arranged according to the field situation; the specifications and the reinforcing bars of the slope protection plate, the L-shaped cover plate, the hook head bracket and the soil retaining plate are determined by calculation of the soil filling pressure.

Compared with the traditional process, the novel slope structure and the reclamation mode have substantial reform and essential difference, and the advantages are mainly expressed in three aspects: firstly, the reclamation area of the side slope is increased from less than 20 percent to more than 95 percent, and the essential breakthrough is realized; secondly, the effective section area of the step planting soil layer is increased from about 1 square meter to more than about 20 square meters, the thickness of the planting layer is increased from dozens of centimeters to more than 2 meters, the data seems to be only quantitative change, and the step-over from quantitative change to qualitative change is actually completed; the land reclamation conditions are not suitable to be converted into suitable conditions, the water and soil conservation state is converted into good state from poor quality, and the ecological reconstruction effect is also converted into the cage with the scallion from the rare hair on the bald head; thirdly, the reclamation efficiency and the reclamation effect are changed from the manual operation of lifting the core and hanging the inner container by the small steps to the safe and efficient mechanized construction, and the essential change and innovation are also realized.

Feasibility analysis of the new process implementation: the traditional excavation process and the side slope structure mode of the surface mine are changed, and the feasibility in various aspects such as theory, practice, technical economy and the like is realized; in terms of safety, the structural reform of the side slope generally reduces the integral side slope angle, the regional environment safety is beneficial and has no harm, and the influence of the change of the step slope angle on the side slope safety can be completely controlled; in terms of technical economy, the mining industry in China has been developed for decades, and the basic national conditions and the mineral conditions are nowadays compared with those of the same felicitous plants; small metal open-pit mines are few, and most of the rest of the open-pit mines except coal mines and iron ore large open-pit mines are building material types; for these mines, the influence of the change of the slope structure on the overall benefits of the mine is basically insignificant; the establishment of ecological benefits and the realization of the transformation from the traditional mining industry to the green mining industry are important and urgent for the sustainable development of the national transportation of civilian life and the social and economic culture.

Description of the drawings:

fig. 1 is a schematic diagram of a rock stratum step retaining and reclamation structure, and the meaning of the marked symbols in the diagram is as follows:

1-retaining support, 2-retaining plate, 3-transverse drain hole,

4-vertical water drainage holes, 5-permeable cover, 6-filtering body,

7-wave terrace, 8-reinforcing anchor rod, 9-transverse flow dispersing pipe,

10-slope drain pipe.

Fig. 2 is a schematic diagram of a soil layer step retaining and reclamation structure, and the meaning of the marked symbols in the diagram is as follows:

2-earth retaining plate, 3-horizontal drainage hole, 4-vertical drainage hole,

5-permeable cover, 6-filtering body, 7-wave floor,

8-reinforced anchor rod, 9-transverse flow-dispersing pipe, 10-slope water-discharging pipe

11-slope protection plate, 12-L-shaped cover plate, 13-hook head bracket.

Fig. 3 is a schematic perspective view of a supporting and blocking structure of a rock step, wherein the meaning of the reference symbols in the drawing is as follows:

1-retaining support, 2-retaining plate, 3-transverse drain hole,

4-vertical water drainage hole, 5-permeable cover, 8-reinforced anchor rod.

Fig. 4 is a schematic perspective view of a soil layer step retaining structure, and the meaning of the reference symbols in the figure is as follows:

2-earth retaining plate, 11-slope protecting plate, 12-L-shaped cover plate,

and 13-eave tile bracket.

The specific implementation method comprises the following steps:

the new process relates to the substantial changes of technical specifications, excavation structures and reclamation processes of the whole open-pit mine industry, the large influence surface and the wide spread range are extremely common, and the single mine change is hardly used as the change; the government competent departments are involved, and organizations and design units, safety supervision departments, production and construction enterprises and related technical personnel receive new technical training, reformulate or improve the technical specifications of the industry, and form a dragon-type integral metamorphic update in China.

Claims (1)

1. The engineering mining method is used for improving the process of the open-pit mine side slope structure and the reclamation mode, the open-pit mine side slope structure and the corresponding reclamation mode in the prior art are traditionally continued for decades, but the congenital defects of the open-pit mine side slope structure and the corresponding reclamation mode cannot adapt to the era trend of developing the green mining industry; the invention carries out comprehensive innovation and transformation on the traditional mode, and has the main technical characteristics as follows:

the step slope angle of the rock layer slope is increased to about 90 degrees, the step height is reduced to below 10 meters, and the platform width is increased to above 8 meters; assembling a step retaining structure by using a retaining support and a retaining plate prefabricated part, thickening backfilled soil to more than 2 meters, and finishing from a slope edge to a slope bottom to form a slightly inclined raised wavy terrace so as to retain rainwater, promote infiltration and preserve soil moisture; the step drainage mode is as follows: a bracket with a special drainage function is arranged at a proper distance, and after the excessive surface water filters sediment, the excessive surface water is drained downwards through a drainage pore channel arranged in the bracket and a side slope drainage pipeline; in the soil slope layer section, the step slope angle is set to be about 80 degrees, the step height is reduced to be below 5 meters, and the platform width is increased to be above 6 meters; assembling the supporting and retaining structures by corresponding prefabricated parts; the backfill mode and the drainage method are basically the same as the arrangement of the rock layer slope; compared with the traditional process, the novel slope structure and the reclamation mode have substantial reformation and essential difference which are mainly shown as follows: the whole effective reclamation area of the side slope is increased from less than 20% to more than 95%, the land condition of the side slope reclamation is converted to be good in nature, the reclamation operation efficiency is converted to be safe and efficient in mechanized construction, and finally the green mining construction in the field of surface mines is promoted to realize breakthrough development.

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