Background
The seepage is a common risk problem of the earth-rock dam, and has various seepage types, complex cause and serious consequences. In the process of reinforcing the earth-rock dam, aiming at the leakage problem of the dam body and the dam foundation, a reinforcing treatment method combining a dam body concrete impervious wall and dam foundation curtain grouting is adopted for most earth-rock dams, the leakage is effectively controlled after the reinforcement, the problem of the seepage damage of the dam body and the dam foundation can be solved, and the seepage safety of the dam is ensured. However, after part of earth and rockfill dam bodies are reinforced by the concrete impervious wall, the problem of seepage of the dam bodies is solved, and the seepage of the joint parts of the dam bodies and the dam foundation is still found in later operation.
The wall thickness of the dam body concrete impervious wall is generally 40-60cm, if the dam foundation impervious curtain is grouted, the construction difficulty is high by adopting the method of drilling the dam body concrete impervious wall, the wall is easy to damage in the drilling process due to the inclination error of the drilling hole, and the dam body grouting curtain can not be effectively connected with the dam body impervious wall.
Therefore, it is necessary to develop an effective connection structure for earth and rockfill dam body seepage prevention and dam foundation seepage prevention.
SUMMERY OF THE UTILITY MODEL
The utility model aims to overcome the defects of the background technology and provide an effective connection structure for preventing seepage of a self-earth-rock dam body and a dam foundation.
In order to achieve the purpose, the technical scheme of the utility model is as follows: effective connection structure of earth and rockfill dam body prevention of seepage and dam foundation prevention of seepage its characterized in that: the dam comprises a dam body, a concrete impervious wall positioned in the middle of the dam body, a grouting hole positioned on the upstream side of the dam body and close to the concrete impervious wall, and curtain grouting positioned at the bottom of the grouting hole.
In the technical scheme, the grouting holes comprise a first-order grouting hole and a second-order grouting hole; the I-order grouting holes and the II-order grouting holes are alternated mutually.
In the technical scheme, the grouting holes are arranged in three rows, the grouting holes are drilled in the first row far away from the concrete impervious wall, the grouting holes are drilled in the third row close to the concrete impervious wall, and the grouting holes are drilled in the second row between the first row of drilling holes and the third row of drilling holes.
In the technical scheme, the curtain grouting is positioned below the third row of drilled holes.
In the technical scheme, the distance between the grouting holes in the first sequence and the grouting holes in the second sequence is 0.8 m, and the distance between the first row of drilling holes and the outer edge of the concrete impervious wall is 2.2 m.
Compared with the prior art, the utility model has the following advantages:
1) the grouting material is simple and convenient to construct, all the used materials are the existing finished product materials, and the grouting material can be put into engineering construction only by simple processing and mixing.
2) The utility model can effectively avoid the possible wall body damage problem caused by the drilling of the concrete impervious wall body and provides a new idea for the impervious connection of the dam body and the dam foundation.
Detailed Description
The embodiments of the present invention will be described in detail with reference to the accompanying drawings, which are not intended to limit the present invention, but are merely exemplary. While the advantages of the utility model will be apparent and readily appreciated by the description.
With reference to the accompanying drawings: effective connection structure of earth and rockfill dam body prevention of seepage and dam foundation prevention of seepage its characterized in that: the dam comprises a dam body 1, a concrete impervious wall 2 positioned in the middle of the dam body 1, a grouting hole 3 positioned on the upstream side of the dam body 1 and close to the concrete impervious wall 2, and curtain grouting 4 positioned at the bottom of the grouting hole 3.
The grouting holes 3 comprise a first-order grouting hole 51 and a second-order grouting hole 52; the sequence I grouting holes 51 and the sequence II grouting holes 52 are alternated mutually.
The grouting holes 3 are provided with three rows, a first row of drilling holes 31 are far away from the concrete impervious wall 2, a third row of drilling holes 33 are close to the concrete impervious wall 2, and a second row of drilling holes 32 are arranged between the first row of drilling holes 31 and the third row of drilling holes 33.
The curtain grouting 4 is located below the third row of holes 33.
The distance between the first-order grouting hole 51 and the second-order grouting hole 52 is 0.8 m, and the distance between the first row of drilling holes 31 and the outer edge of the concrete impervious wall 2 is 2.2 m.
The construction method of the effective connection structure of the earth-rock dam body seepage prevention and the dam foundation seepage prevention is characterized by comprising the following steps:
step 1: arranging three rows of grouting holes 3 on the top surface of the dam body 1 at the upstream side, wherein the drilling sequence of the grouting holes 3 is a first row of drilling holes 31, a second row of drilling holes 32 and a third row of drilling holes 33; the subsequent grouting adopts a hole spacing grouting method, namely, only grouting I-order grouting holes 51;
step 2: mixing cement, fly ash and bentonite as raw materials to form a solution, and mixing the solution and water according to a water-cement ratio of 0.7-1.0:1 to form stable slurry; grouting the first row of drill holes 31 and the second row of drill holes 32;
and step 3: and filling and grouting are carried out on the third row of drill holes 33, and construction is completed.
In the step 1, a grouting hole 3 is drilled vertically, and the depth of the grouting hole 3 is the same as the height of the concrete impervious wall 2; the distance between the first-order grouting hole 51 and the second-order grouting hole 52 is 0.8 m, and the construction is performed in sections, wherein each section is 3.2 m long; the first row of drilling holes 31 is 2.2 meters away from the outer edge of the concrete impervious wall 2.
In the step 2: the grouting pressure of the drilling rod is 0.1 MPa; the perfusion depth is controlled to be 3 meters; the diffusion radius of the slurry was controlled to 1.6 m.
In the step 3: the perfusion depth is controlled to be 3 meters; the grouting pressure of the drilling rod is 0.5-1 MPa.
In practical use, the utility model forms a base structure which is tightly connected with the concrete impervious wall 2 at the bottom end of the upstream side of the dam body concrete impervious wall 2 through a comprehensive grouting technology, and the base structure is used as a grouting board for dam foundation curtain grouting 4, so that a dam foundation of the dam body 1 forms a complete impervious system through effective connection of the grouting boards.
The utility model realizes the effective connection between the dam body 1 and the dam foundation; the method comprises the steps of firstly, alternately and alternately grouting by sections, grouting I-order grouting holes 51 (each section is 3.2 meters long, the grouting sections are alternately constructed at intervals along the axis direction of a dam, and grouting is performed in a jump hole interval grouting mode to prevent grout from losing in order to prevent adjacent holes from crossing grout, and stable grout (the stable grout refers to cement grout which is mixed with a small amount of stabilizer, has no more than 5% of precipitation water within 2 hours and is not easy to precipitate and separate and has high stability) is poured at the peripheral side of each section, and the stable grout can be divided into cement stable grout, mixed stable grout, paste stable grout and quick-setting paste stable grout according to different material components to form closed periphery and is refilled for grouting.
The grouting sequence of the grouting holes 3 adopts a hole spacing grouting method, namely after one I-sequence grouting hole 51 is injected, one II-sequence grouting hole 52 is spaced, then the next I-sequence grouting hole 51 is injected, and no matter horizontal grouting or longitudinal grouting is carried out, one II-sequence grouting hole 52 is spaced.
Other parts not described belong to the prior art.