Concrete dam stepped construction anti-seepage method

Abstract

The invention discloses a concrete dam stepped construction anti-seepage method, and belongs to the technical field of concrete dam anti-seepage construction. The method comprises the following steps: step 1, determining a combination area of roller compacted concrete and distorted concrete and the position of a boundary; 2, dividing the combined area into a plurality of paving layers from bottom to top; step 3, preparing a template; fourthly, construction of the bottommost paving layer is completed; step 5, mounting and calibrating the template of the paving layer of the secondary bottom layer, sequentially constructing the roller compacted concrete and the distorted concrete of the paving layer of the secondary bottom layer, then fully vibrating the distorted concrete, and removing the template of the paving layer; sixthly, according to the fifth step, construction of the remaining paving layers is completed from bottom to top in sequence; seventhly, the concrete of the top paving layer is subjected to bin face maintenance, and finally the construction joint of the roller compacted concrete and the distorted concrete in the combining area is in a step shape. The anti-seepage performance and the anti-seepage effect of the stepped construction joints are better, and then seepage at the construction joints is prevented.

Description

Technical Field

[0001] The invention relates to a concrete dam step-type construction anti-seepage method, belonging to the technical field of concrete dam anti-seepage construction. Background Art

[0002] In recent years, concrete dams have been widely used in water conservancy projects due to their advantages of fast construction speed and short construction period. When building concrete dams, concrete is often divided into rolled concrete and modified concrete. Modified concrete is mainly used in places around the dam that cannot be rolled or are not rolled sufficiently.

[0003] However, construction gaps are prone to occur at the junction of RCC and deformed concrete, and seepage is very likely to occur at the construction gaps. At present, the main method of preventing seepage is to add waterproof components at the construction gaps, for example, adding anti-seepage curtains, geotextiles or water-stopping parts at the construction gaps for anti-seepage. However, adding waterproof components for anti-seepage is a passive anti-seepage method and cannot fundamentally solve the problem of seepage in the construction gaps at the junction of RCC and deformed concrete. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a step-by-step construction anti-seepage method for concrete dams.

[0005] The present invention is achieved through the following technical solutions:

[0006] A step-by-step construction anti-seepage method for a concrete dam comprises the following steps:

[0007] Step 1: According to the construction drawings, clarify the combined area of ​​​​the rolled concrete and the deformed concrete, and measure and determine the location of the dividing line between the rolled concrete and the deformed concrete in advance;

[0008] Step 2: Divide the combined area of ​​the roller compacted concrete and the modified concrete into multiple paving layers from bottom to top according to the construction process and the pouring height of each bin;

[0009] Step 3: prepare a template for separating the rolled concrete and the modified concrete in the paving layer;

[0010] Step 4: Install and calibrate the template of the bottom paving layer, and sequentially construct the roller compacted concrete and modified concrete of the bottom paving layer, then fully vibrate the modified concrete, and remove the template of the paving layer;

[0011] Step 5: Install and calibrate the template of the secondary bottom paving layer, and sequentially construct the roller compacted concrete and modified concrete of the secondary bottom paving layer, then fully vibrate the modified concrete, and remove the template of the paving layer;

[0012] Step 6: Referring to step 5, complete the construction of the roller compacted concrete and modified concrete of the remaining paving layers from bottom to top;

[0013] Step seven, the surface of the rolled concrete and deformed concrete of the top paving layer is maintained, and the construction joint between the rolled concrete and deformed concrete in the combined area is finally stepped.

[0014] In the step 2, the bonding area between the roller compacted concrete and the modified concrete is divided into 3 to 6 paving layers from bottom to top.

[0015] The thickness of all paving layers divided in step 2 is equal.

[0016] In the step three, the scale 11 is made by combining the thickness of all paving layers.

[0017] The scale 11 is provided with identification segments for respectively indicating the thickness of each paving layer.

[0018] In all paving layers of the combined area, the width of the roller compacted concrete decreases layer by layer from bottom to top, and the width of the deformed concrete increases layer by layer from bottom to top.

[0019] The deformed concrete step width T0 of the bottom paving layer in the combining area shall not be less than 0.5 times the designed filling width T of the deformed concrete.

[0020] Except for the lowest paving layer, the step width of the remaining paving layers in the combined area shall not be less than 0.2 times the designed filling width T of the modified concrete.

[0021] Except for the lowest paving layer, the step width of the remaining paving layers in the bonding area is not greater than 0.5 times the step width T0 of the deformed concrete of the lowest paving layer.

[0022] The steps 4, 5 and 6 are continuously constructed.

[0023] The beneficial effects of the present invention are:

[0024] 1. The combined area of ​​the rolled concrete and the deformed concrete is divided into multiple paving layers from bottom to top, and all the paving layers are constructed in sequence from bottom to top. At the same time, during the construction of each paving layer, the rolled concrete and the deformed concrete in the paving layer are separated by a template to determine the boundary line between the rolled concrete and the deformed concrete in the paving layer, so that the construction joint formed by the rolled concrete and the deformed concrete in the combined area is stepped. Compared with the traditional straight construction joint, the stepped construction joint has better anti-seepage performance and anti-seepage effect, thereby preventing seepage from occurring at the construction joint, fundamentally solving the problem of seepage occurring in the construction joint at the combination of the existing rolled concrete and the deformed concrete.

[0025] 2. When the bottom layer, the middle layer and the top layer are all filled and the modified concrete is fully vibrated, the modified concrete in the modified concrete filling area III flows along the mud flow direction, and then mixes with the rolled concrete in the transition zone I to form new modified concrete, and finally the transition zone I is transformed into the anti-seepage reserve area II, which increases the anti-seepage area and forms the anti-seepage reserve area II on the basis of the original anti-seepage, which significantly improves the anti-seepage performance and anti-seepage effect of the junction of rolled concrete and modified concrete, improves the safety of dam operation, and effectively solves the leakage problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a construction step diagram of the present invention;

[0027] Figure 2 This is a schematic diagram of the explosion structure of the second embodiment of the present invention;

[0028] Figure 3 for Figure 2 Schematic diagram of the main structure;

[0029] Figure 4 This is a schematic diagram of the structure of the concrete connection on both sides of the stepped construction joint.

[0030] In the figure: 1-formwork E, 2-formwork F, 3-formwork G, 4-roller compacted concrete area A, 5-roller compacted concrete area B, 6-roller compacted concrete area C, 7-abnormal concrete area H, 8-abnormal concrete area Q, 9-abnormal concrete area K, 10-mud flow direction, 11-thickness scale, I-transition area, II-reserve area, III-abnormal concrete filling area. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0032] Embodiment 1:

[0033] like Figure 1 As shown, a step-by-step construction anti-seepage method for a concrete dam according to the present invention comprises the following steps:

[0034] Step 1: According to the construction drawings, clarify the combination area of ​​​​RCC and deformed concrete, and measure in advance to determine the location of the dividing line between RCC and deformed concrete.

[0035] Step 2: Divide the combined area of ​​RCC and modified concrete into multiple paving layers from bottom to top according to the construction technology and the pouring height of each bin.

[0036] Step 3: Prepare a template for separating the RCC and deformed concrete in the paving layer. The template is used to separate the RCC and deformed concrete in the same paving layer to determine the boundary between the RCC and deformed concrete in the same paving layer, thereby ensuring that the joint between the RCC and deformed concrete in the final bonding area is stepped.

[0037] Step 4: Install and calibrate the formwork of the bottom paving layer, and construct the rolled concrete and modified concrete of the bottom paving layer in sequence, then fully vibrate the modified concrete and remove the formwork of the paving layer.

[0038] Step 5: Install and calibrate the formwork of the secondary bottom paving layer, and construct the rolled concrete and deformed concrete of the secondary bottom paving layer in sequence, then fully vibrate the deformed concrete and remove the formwork of the paving layer.

[0039] Step 6. Referring to step 5, complete the construction of the roller compacted concrete and modified concrete of the remaining paving layers from bottom to top.

[0040] Step seven, the surface of the rolled concrete and deformed concrete of the top paving layer is maintained, and the construction joint between the rolled concrete and deformed concrete in the combined area is finally stepped.

[0041] Specifically, the bonding area between the rolled concrete and the deformed concrete is divided into multiple paving layers from bottom to top, and all the paving layers are constructed sequentially from bottom to top. At the same time, during the construction of each paving layer, the rolled concrete and the deformed concrete in the paving layer are separated by templates to determine the dividing line between the rolled concrete and the deformed concrete in the paving layer, so that the construction joint formed by the rolled concrete and the deformed concrete in the bonding area is stepped. Compared with the traditional straight construction joint, the stepped construction joint has better anti-seepage performance and anti-seepage effect, thereby preventing seepage from occurring at the construction joint, fundamentally solving the problem of seepage occurring in the construction joint at the bonding area between the rolled concrete and the deformed concrete.

[0042] In addition, the deformed concrete on the upper side of the stepped construction joint will partially flow into the rolled concrete on the lower side of the stepped construction joint during the full vibration process, and combine with the rolled concrete to form new deformed concrete, further improving the anti-seepage performance and anti-seepage effect at the stepped construction joint.

[0043] In the step 2, the combined area of ​​the roller compacted concrete and the deformed concrete is divided into 3 to 6 paving layers from bottom to top. If the number of divided paving layers is greater than 6, although the anti-seepage performance and anti-seepage effect at the stepped construction joints can be further improved, the construction efficiency of the concrete dam will also be reduced; if the number of divided paving layers is less than 3, although the construction efficiency of the concrete dam can be improved, the anti-seepage performance and anti-seepage effect at the stepped construction joints will also be relatively reduced.

[0044] The thickness of all paving layers divided in step 2 is equal.

[0045] In the step three, the scale 11 is made by combining the thickness of all paving layers.

[0046] The scale 11 is provided with marking segments for indicating the thickness of each paving layer, so as to control the thickness of the paving layer by referring to the marking segments on the scale 11.

[0047] In all paving layers of the combined area, the width of the roller compacted concrete decreases layer by layer from bottom to top, and the width of the deformed concrete increases layer by layer from bottom to top.

[0048] The deformed concrete step width T0 of the bottom paving layer in the joint area shall not be less than 0.5 times the designed filling width T of the deformed concrete.

[0049] Except for the lowest paving layer, the step width of the remaining paving layers in the combined area shall not be less than 0.2 times the designed filling width T of the modified concrete.

[0050] The step width of the remaining paving layers in the combined area, except for the bottom paving layer, is not greater than 0.5 times the step width T0 of the deformed concrete of the bottom paving layer. The step width of the remaining paving layers can also be determined according to actual conditions, but must be convenient for the vibrator to vibrate the concrete.

[0051] The steps 4, 5 and 6 are continuously constructed.

[0052] Each paving layer must first be poured with rolled concrete and then filled with deformed concrete. While fully vibrating the deformed concrete, the formwork of the current paving layer is removed and the formwork of the next paving layer is installed. The whole process is kept continuous and completed before the concrete begins to set.

[0053] Embodiment 2:

[0054] like Figures 1 to 4 As shown, a step-by-step construction anti-seepage method for a concrete dam according to the present invention comprises the following steps:

[0055] Step 1: According to the construction drawings, clarify the combination area of ​​​​RCC and deformed concrete, and measure in advance to determine the location of the dividing line between RCC and deformed concrete.

[0056] Step 2: According to the construction technology and the pouring height of each bin, the combined area of ​​the roller compacted concrete and the modified concrete is divided into three paving layers from bottom to top. The bottom paving layer includes the roller compacted concrete area A 4 and the modified concrete area H 7; the middle paving layer includes the roller compacted concrete area B 5 and the modified concrete area Q 8; the top paving layer includes the roller compacted concrete area C 6 and the modified concrete area K 9.

[0057] Step 3: Prepare the templates for separating the RCC and the modified concrete in the paving layer, that is, prepare the template E1 for the bottom paving layer, the template F2 for the middle paving layer, and the template G3 for the top paving layer.

[0058] Step 4: Install and calibrate the template E1 of the bottom paving layer, and sequentially construct the roller compacted concrete A area 4 and the modified concrete H area 7 of the bottom paving layer, then fully vibrate the modified concrete, and remove the template E1 of the paving layer. During the construction of each joint, maintain construction continuity and prohibit the occurrence of gaps.

[0059] Step 5: Install and calibrate the formwork F2 of the middle layer paving layer, and sequentially construct the roller compacted concrete B area 5 and the modified concrete Q area 8 of the middle layer paving layer, then fully vibrate the modified concrete, and remove the formwork F2 of the paving layer. During the construction of each joint, the construction continuity is maintained and no gaps are allowed.

[0060] Step 6: Install and calibrate the template G3 of the top paving layer, and sequentially construct the roller compacted concrete C area 6 and the modified concrete K area 9 of the top paving layer, then fully vibrate the modified concrete, and remove the template G3 of the paving layer. During the construction of each joint, maintain construction continuity and prohibit the occurrence of gaps.

[0061] Step seven, the surface of the rolled concrete and deformed concrete of the top paving layer is maintained, and the construction joint between the rolled concrete and deformed concrete in the combined area is finally stepped.

[0062] like Figure 3 As shown in the figure, the RCC area on the lower side of the stepped construction joint is the transition zone I, and the abnormal concrete area on the upper side of the stepped construction joint is the abnormal concrete filling zone III. When the bottom layer, the middle layer and the top paving layer are all filled, and in the process of fully vibrating the abnormal concrete, the abnormal concrete in the abnormal concrete filling zone III flows along the mud flow direction 10, and then mixes with the RCC in the transition zone I to form a new abnormal concrete, and finally the transition zone I becomes the anti-seepage reserve zone II, which increases the anti-seepage area, forms the anti-seepage reserve zone II on the basis of the original anti-seepage, and significantly improves the anti-seepage performance and anti-seepage effect at the junction of the RCC and the abnormal concrete.

Claims

1. A step-by-step construction anti-seepage method for a concrete dam, characterized in that: The following steps are involved: Step 1: According to the construction drawings, clarify the combined area of ​​​​the rolled concrete and the deformed concrete, and measure and determine the location of the dividing line between the rolled concrete and the deformed concrete in advance; Step 2: Divide the combined area of ​​the roller compacted concrete and the modified concrete into multiple paving layers from bottom to top according to the construction process and the pouring height of each bin; Step 3: prepare a template for separating the rolled concrete and the modified concrete in the paving layer; Step 4: Install and calibrate the template of the bottom paving layer, and sequentially construct the roller compacted concrete and modified concrete of the bottom paving layer, then fully vibrate the modified concrete, and remove the template of the paving layer; Step 5: Install and calibrate the template of the secondary bottom paving layer, and sequentially construct the roller compacted concrete and modified concrete of the secondary bottom paving layer, then fully vibrate the modified concrete, and remove the template of the paving layer; Step 6: Referring to step 5, complete the construction of the roller compacted concrete and modified concrete of the remaining paving layers from bottom to top; Step seven, the surface of the rolled concrete and deformed concrete of the top paving layer is maintained, and the construction joint between the rolled concrete and deformed concrete in the combined area is finally stepped.

2. The step-by-step anti-seepage method for concrete dam construction according to claim 1, characterized in that: In the step 2, the bonding area between the roller compacted concrete and the modified concrete is divided into 3 to 6 paving layers from bottom to top.

3. The step-by-step anti-seepage method for concrete dam construction according to claim 1 or 2, characterized in that: The thickness of all paving layers divided in step 2 is equal.

4. The step-by-step construction anti-seepage method for concrete dams according to claim 1, characterized in that: In the step 3, a ruler (11) is produced by combining the thicknesses of all paving layers.

5. The step-by-step anti-seepage method for concrete dam construction according to claim 4, characterized in that: The scale (11) is provided with identification segments for respectively indicating the thickness of each paving layer.

6. The step-by-step construction anti-seepage method for concrete dams according to claim 1, characterized in that: In all paving layers of the combined area, the width of the roller compacted concrete decreases layer by layer from bottom to top, and the width of the deformed concrete increases layer by layer from bottom to top.

7. The step-by-step anti-seepage method for concrete dam construction according to claim 1, characterized in that: The deformed concrete step width T0 of the bottom paving layer in the combining area shall not be less than 0.5 times the designed filling width T of the deformed concrete.

8. The step-by-step anti-seepage method for concrete dam construction according to claim 1, characterized in that: Except for the lowest paving layer, the step width of the remaining paving layers in the combined area shall not be less than 0.2 times the designed filling width T of the modified concrete.

9. The step-by-step construction anti-seepage method for concrete dams according to claim 1, characterized in that: Except for the lowest paving layer, the step width of the remaining paving layers in the bonding area is not greater than 0.5 times the step width T0 of the deformed concrete of the lowest paving layer.

10. The step-by-step construction anti-seepage method for concrete dams according to claim 1, characterized in that: The steps 4, 5 and 6 are continuously constructed.

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