Artificial dam of distributed coal mine underground reservoir and its constructing method
The present disclosure provides an artificial dam of a distributed coal mine underground reservoir and its constructing method. The artificial dam comprises a support layer ( 10 ), an anti-seepage layer ( 20 ), and a concrete structure layer ( 30 ) that are successively formed in an auxiliary roadway ( 1 ) from inside to outside, the concrete structure layer ( 30 ) being embedded into a security coal pillar ( 2 ) and/or surrounding rock ( 3 ) around the auxiliary roadway ( 1 ). Because the concrete structure layer ( 30 ) is embedded into the security coal pillar ( 2 ) and/or the surrounding rock ( 3 ) around the auxiliary roadway ( 1 ), the artificial dam is combined to the security coal pillar ( 2 ) to together form a dam for an underground reservoir. Due to multi-layer design, anti-seepage performance and structural strength of the dam can meet the water storage requirements of the underground reservoir.
1. An artificial dam of distributed coal mine underground reservoir, wherein the artificial dam comprises a support layer, an anti-seepage layer, and a concrete structure layer, which are successively formed in an auxiliary roadway from inside to outside, wherein the concrete structure layer is embedded into security coal pillars and/or surrounding rocks around the auxiliary roadway, emergency-observing holes being provided in the support layer, the anti-seepage layer, and the concrete structure layer, the anti-seepage layer being formed from at least one of gangue and loess, the anti-seepage layer being disposed between the support layer and the concrete structure layer such that the anti-seepage layer fills the space between the support layer and the concrete structure layer.
2. The artificial dam according to claim 1 , wherein the concrete structure layer is embedded into the security coal pillars and/or the surrounding rocks in the depth of 30-80 cm.
3. The artificial dam according to claim 1 , wherein multiple bolts are provided between the concrete structure layer and the security coal pillars and/or the surrounding rocks.
4. The artificial dam according to claim 3 , wherein the length of the bolts is 180-210 cm, and the depth of the bolts inserted into the security coal pillars and/or the surrounding rocks is 30-80 cm.
5. The artificial dam according to claim 1 , wherein multiple steel joists are embedded into the concrete structure layer, and the multiple steel joists constitute a shape of “#”.
6. The artificial dam according to claim 1 , wherein the support layer is a brick and concrete structure layer with a thickness of 1.5 m.
7. The artificial dam according to claim 1 , wherein the anti-seepage layer is a gangue structure layer or loess structure layer with a thickness of 2 m.
8. The artificial dam according to claim 1 , wherein a cross section of the artificial dam is rectangular or arc-shaped, and a concave of the artificial dam with arc-shaped cross section faces the underground reservoir.
9. A constructing method of an artificial dam for distributed coal mine underground reservoir, wherein the method comprises the steps of:
selecting positions for constructing the artificial dam between security coal pillars in an auxiliary roadway;
in the auxiliary roadway, successively forming a support layer and an anti-seepage layer from inside to outside;
abutting outside of the anti-seepage layer, notching in the security coal pillars and/or surrounding rocks around the auxiliary roadway, to form recesses;
in the recesses, inserting multiple bolts into the security coal pillars and/or the surrounding rocks;
embedding steel joists into the recesses;
injecting concrete with high pressure to form a concrete structure layer in the recesses so that the anti-seepage layer is disposed between the support layer and the concrete structure layer such that the anti-seepage layer fills the space between the support layer and the concrete structure layer; and
providing emergency-observing holes in the support layer, the anti-seepage layer, and the concrete structure layer.
10. The method according to claim 9 , wherein the step of selecting positions for constructing the artificial dam comprises:
prospecting rock-coal properties, stratums, and structures of roadways to be constructed by using geophysical prospecting and drilling means; and
selecting locations with simple structure and stable rock-coal property as constructing sites of the artificial dam.
11. The method according to claim 9 , wherein before the artificial dam is constructed, the method further comprises:
estimating water pressure in the auxiliary roadway; and
setting a shape of a cross section of the artificial dam according to the water pressure.