Tailings dam flood interception dam assisted by using mining and beneficiation waste rock and its construction method

Abstract

The present invention discloses a tailings dam constructed with the aid of mining waste rock and a construction method thereof. The flood diversion dam includes a gravity dam body cast with rubble stone concrete and a back-pressure platform. The back-pressure platform is filled with mining waste rock. The back-pressure platform is constructed on the downstream side of the gravity dam body, and the back-pressure platform is arranged in contact with the inclined surface of the downstream side of the gravity dam body. The back-pressure platform spanning the entire riverbed of the present invention can significantly improve the overall stability and safety of the flood diversion dam, effectively control the uneven settlement caused by the gravity dam on the weak covering layer foundation, greatly reduce the risk of dam body cracking, and prevent the gravity dam covering layer foundation from deep shear overall instability and damage. The platform filling construction of the present invention keeps rising synchronously with the gravity dam body, and the back-pressure platform is used to build the access road to the warehouse during the construction period, which effectively solves the problem of transporting tens of thousands of cubic meters of rubble stone into the warehouse during the gradual casting and rising process of the rubble stone concrete gravity dam.

Description

Technical Field

[0001] The present invention belongs to the technical field of mine tailings pond engineering, and specifically relates to a tailings pond flood interception dam constructed with the aid of mining and dressing waste rock, and a construction method thereof. Background Art

[0002] Tailings dams are generally constructed in streams upstream of the tailings pond. Their function is to intercept floodwaters generated in the valley during the flood season and discharge them downstream through flood discharge channels, thereby ensuring the flood control safety of the tailings pond during the flood season. The dam site of the flood diversion dam usually has a deep overburden foundation, and the dam type selected tends to be a gravity dam with reliable working performance and simple construction technology. An important issue in building a gravity dam on an overburden foundation is how to ensure the overall stability and safety of the gravity dam. In addition, how to prevent harmful uneven settlement of the gravity dam on the overburden foundation and prevent deep shear overall instability and failure of the overburden foundation under the action of the dam body are also technical issues that need to be handled with caution. For economic and environmental purposes, a total of tens of thousands of cubic meters of rubble stone needs to be added during the pouring of the concrete gravity dam. This requires solving the problem of transporting the rubble stone into the warehouse during the gradual pouring and rising of the gravity dam.

[0003] Mines generate large amounts of waste rock during the mining and mineral processing processes. Discarding this waste rock in waste rock dumps not only occupies significant land but also damages the surrounding ecological environment. Properly utilizing this waste rock to construct flood interception dams and counterpressure platforms could yield significant economic and ecological benefits. Summary of the Invention

[0004] The object of the present invention is to provide a tailings pond flood interception dam constructed with the aid of mining and dressing waste rock and a construction method thereof, thereby solving the above-mentioned problems.

[0005] To achieve the above-mentioned purpose, the present invention first discloses a tailings flood intercepting dam constructed with the assistance of mining and dressing waste rock, comprising a gravity dam body and a back-pressure platform. The gravity dam body is cast with rubble concrete, and the back-pressure platform is filled with mining and dressing waste rock. The back-pressure platform is constructed on the downstream side of the gravity dam body, and the back-pressure platform is arranged in contact with the inclined surface of the downstream side of the gravity dam body.

[0006] Furthermore, the height of the counter-pressure platform is 45%-55% of the height of the gravity dam body.

[0007] Furthermore, the width of the top of the back-pressure platform is greater than or equal to 10 meters, and the slope of the downstream side of the back-pressure platform is greater than or equal to 1:1.8.

[0008] Furthermore, a flood diversion dam construction access road is provided on the counter-pressure platform, and the flood diversion dam construction access road is provided in a zigzag shape on the inclined surface on the downstream side of the counter-pressure platform.

[0009] Furthermore, the roadbed of the flood diversion dam construction access road on the counter-pressure platform is a compacted mining waste rock slope, the road surface is an 18-22 cm thick mud-bound gravel road surface, the road surface width is not less than 6 meters, the slope is not more than 11%, and the turning radius is not less than 15 meters.

[0010] Furthermore, the gravity dam body is provided with a flood diversion dam construction access road. The flood diversion dam construction access road is constructed from the center of the top of the counter-pressure platform to the left and right banks at a slope of 9%-11% using mining waste rock filling. The road surface of the flood diversion dam construction access road is 18-22 cm thick mud-bound gravel road surface, and the road surface width is not less than 6 meters.

[0011] Then, the present invention discloses a construction method of a tailings dam constructed with mining and dressing waste rock as an auxiliary, comprising the following steps:

[0012] 1) Keep the backpressure platform filling and the gravity dam body concrete pouring rising synchronously, and use the slope of the backpressure platform to form a zigzag flood interception dam construction access road, which directly reaches the concrete pouring warehouse surface of the gravity dam body that is flush with the top surface of the backpressure platform construction;

[0013] 2) When the gravity dam body is higher than the top elevation of the counter-pressure platform, the flood intercepting dam construction access road is built from the center of the top of the counter-pressure platform to the left and right banks at a slope of 9%-11% to the concrete pouring surface of the gravity dam.

[0014] Compared with the prior art, the advantages of the present invention are:

[0015] 1. The back pressure platform spanning the entire riverbed described in the present invention can significantly improve the overall stability and safety of the flood interception dam, effectively control the uneven settlement caused by the gravity dam on the weak overburden foundation, greatly reduce the risk of dam cracking, and prevent deep shear overall instability and failure of the gravity dam overburden foundation.

[0016] 2. The counter-pressure platform of the present invention is filled with mine waste rock, which can effectively utilize the excess waste rock generated by mineral processing and mining, reduce the amount of waste rock treatment engineering, save costs, and is beneficial to protecting the local ecological environment, with good ecological benefits.

[0017] 3. The counter-pressure platform of the present invention facilitates the construction of a construction road for the concrete entry of the flood intercepting dam body. By utilizing this construction road, a large amount of rubble stones required for the pouring of the dam body concrete can be directly transported into the warehouse by dump trucks, thereby greatly improving the pouring efficiency of the rubble stone concrete of the gravity dam body and saving the transportation time and cost of the rubble stones. That is, the construction of the entry road during the construction period by utilizing the counter-pressure platform effectively solves the problem of transporting tens of thousands of cubic meters of rubble stones into the warehouse during the gradual pouring and rising process of the rubble stone concrete gravity dam.

[0018] The present invention will be described in further detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0020] Figure 1 It is a structural schematic diagram of a tailings pond flood interception dam constructed with the aid of mining and dressing waste rock according to a preferred embodiment of the present invention.

[0021] Legend:

[0022] 1. Gravity dam body; 2. Counterpressure platform; 3. Access road for flood diversion dam construction. DETAILED DESCRIPTION

[0023] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0024] like Figure 1 As shown, the present invention discloses a tailings flood interception dam constructed with mining and dressing waste rock. This dam, constructed for a mining company's tailings flood interception dam, comprises a gravity dam body 1 and a backpressure platform 2. The gravity dam body 1 is a C20 rubble concrete gravity dam with a crest elevation of 1790 meters, a dam height of 24 meters, a crest width of 4 meters, and a crest length of 238 meters. The dam foundation is a soft foundation of Quaternary pebbles interbedded with silty clay. The upstream face of the gravity dam body 1 is vertically inclined 5 meters below the crest, with a lower slope ratio of 1:0.3 and a downstream slope ratio of 1:0.8. The total amount of rubble added to the concrete of the gravity dam body 1 exceeds 20,000 tons. The mining company produces more than 10 million tons of waste rock every year in the mining and dressing of vanadium-titanium magnetite. The waste rock mass mainly contains minerals such as pyroxene, basic plagioclase, olivine, and amphibole. Its physical and mechanical properties are dense, hard, high compressive strength, high apparent density, and low surface water absorption. It is very suitable for use as a back pressure platform for building gravity dams, and is also very suitable for use as rough stone added in the pouring of dam concrete.

[0025] This flood interception dam utilizes mining waste rock to construct a counterpressure platform 2 downstream of the dam, spanning the entire river valley. The platform's top elevation is 1777 meters, its width is 10 meters, and its downstream slope is 1:1.85. This not only effectively improves the overall stability and safety of the gravity dam body 1, but also provides a convenient way to directly transport large amounts of rough rock into the silo during the concrete construction period of the gravity dam body 1, promoting the utilization of mining waste rock and achieving significant economic and ecological benefits.

[0026] 1. Construction of counter-pressure platform

[0027] Using mining waste rock, a counterpressure platform 2 was constructed downstream of the flood interception dam, spanning the entire river valley. It is 12 meters high, 10 meters wide at the top, and has a downstream slope of 1:1.85. Calculations show that due to the counterpressure support provided by the counterpressure platform 2, the overall anti-sliding stability safety factor of the flood interception dam meets relevant regulatory requirements, with differential settlement of the dam foundation surface exceeding 1 cm. The deep anti-sliding stability safety factor of the dam foundation overburden layer is significantly greater than the regulatory allowable value.

[0028] The specific construction steps of the back pressure platform 2 are as follows:

[0029] Step 1: As the gravity dam body 1 of the flood interceptor dam is poured and raised in layers, the backpressure platform 2 is filled and raised synchronously with the gravity dam body 1. When the concrete strength age of the newly poured layer (layer thickness 2m) reaches 15 days, the next layer of backpressure platform 2 can be filled and constructed.

[0030] Step 2: The waste rock on counterpressure platform 2 was laid and compacted along the axis of the gravity dam. Counterpressure platform 2 spanned the entire riverbed. The waste rock was transported by 20t dump trucks, leveled by bulldozers, and compacted by vibratory rollers. The compacted layer thickness was controlled to 1.0m. This means that for every one layer of concrete poured for the gravity dam body 1, two layers of concrete were poured for counterpressure platform 2.

[0031] 2. Construction of access road 3 for flood diversion dam construction below the top elevation of 1777.0 meters for counterpressure platform 2

[0032] Step 1: While the counter pressure platform 2 is being constructed, mine waste rock is used to fill the roadbed of the construction road, such as Figure 1 As shown, after the roadbed is formed, vibration compaction must also be used to ensure that the road does not sink during use.

[0033] Step 2: Construction of mud-stone pavement. The crushed stone and clay must be mixed evenly, the paving thickness must be in place at one time, water must be sprinkled moderately, and the road must be rolled with a vibrating roller. During the rolling process, stone chips must be added in time, and the number of rolling times must be controlled to 4-6 times.

[0034] Step 3: Zigzag along the downstream slope of counter-pressure platform 2 to reach the concrete pouring area of gravity dam body 1, which is flush with the top surface of counter-pressure platform 2. The construction road needs to be watered and maintained during use to prevent mud and gravel from forming on rainy days and dust on sunny days.

[0035] 3. Construction of access road 3 for flood interception dam construction at a top elevation of 1777.0 meters above the counterpressure platform 2

[0036] Step 1: Use mine waste rock to build the roadbed of the construction road from the center of the top of the counter-pressure platform 2 to the left and right banks with a slope of 10% to the concrete bin surface elevation of the gravity dam body 1, and use vibratory roller to compact the roadbed.

[0037] Step 2: Pave the mud-stone pavement and compact it with a vibratory roller. During the compaction process, stone chips should be added in time and the number of compaction times should be controlled to 4-6 times. After compaction, the thickness of the mud-stone pavement is 20 cm and the width of the pavement is 6 meters.

[0038] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A tailings dam constructed with mining and dressing waste rock as an auxiliary, characterized in that: The invention comprises a gravity dam body (1) and a back-pressure platform (2), wherein the gravity dam body (1) is cast with rough stone concrete, and the back-pressure platform (2) is filled with mining waste rock. The back-pressure platform (2) is built on the downstream side of the gravity dam body (1), and the back-pressure platform (2) is arranged in contact with the inclined surface of the downstream side of the gravity dam body (1); the height of the back-pressure platform (2) is 45%-55% of the height of the gravity dam body (1); and the slope of the downstream side of the back-pressure platform (2) is greater than or equal to 1:1.

8.

2. The tailings dam constructed with mining and dressing waste rock as an auxiliary tool according to claim 1 is characterized in that: The width of the top of the back pressure platform (2) is greater than or equal to 10 meters.

3. The tailings flood interception dam constructed with mining and dressing waste rock as an auxiliary tool according to any one of claims 1-2, characterized in that: A flood intercepting dam construction access road (3) is provided on the counter-pressure platform (2), and the flood intercepting dam construction access road (3) is arranged in a zigzag shape on an inclined surface on the downstream side of the counter-pressure platform (2).

4. The tailings dam constructed with mining and dressing waste rock as an auxiliary means according to claim 3 is characterized in that: The roadbed of the flood intercepting dam construction access road (3) on the counter-pressure platform (2) is a compacted mining waste rock slope, the road surface is an 18-22 cm thick mud-bonded gravel road surface, the road surface width is not less than 6 meters, the slope is not more than 11%, and the turning radius is not less than 15 meters.

5. The tailings dam constructed with mining and dressing waste rock as an auxiliary means according to claim 3 is characterized in that: The flood intercepting dam construction access road (3) is provided on the gravity dam body (1). The flood intercepting dam construction access road (3) is a construction road that is constructed from the center of the top of the counter-pressure platform (2) to the left and right banks at a slope of 9%-11% using mining waste rock filling. The road surface of the flood intercepting dam construction access road (3) is a mud-bound gravel road surface with a thickness of 18-22 cm and a road surface width of not less than 6 meters.

6. A method for constructing a tailings dam using mining and dressing waste rock as an auxiliary means, comprising the method according to any one of claims 1 to 5, wherein: The steps include: 1) The filling of the counter-pressure platform (2) and the concrete pouring of the gravity dam body (1) are kept rising synchronously, and a zigzag flood intercepting dam construction access road (3) is formed by turning back the slope of the counter-pressure platform (2) to directly reach the concrete pouring warehouse surface of the gravity dam body (1) which is flush with the construction top surface of the counter-pressure platform (2); 2) When the gravity dam body (1) is higher than the top elevation of the counter-pressure platform (2), the flood intercepting dam construction access road (3) is constructed from the center of the top of the counter-pressure platform (2) to the left and right banks at a slope of 9%-11% to the concrete pouring surface of the gravity dam.

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