WO2006026888A1

WO2006026888A1 - An incline bed and horizontal push method for constructing a dam with rolled concrete

Info

Publication number: WO2006026888A1
Application number: PCT/CN2004/000880
Authority: WO
Inventors: Lichen Yang; Guangran Yang
Original assignee: Lichen Yang; Guangran Yang
Priority date: 2004-07-29
Filing date: 2004-07-29
Publication date: 2006-03-16

Abstract

An incline bed and horizontal push method for constructing a dam with rolled concrete comprises the following steps: laying-out, slot surface green cutting, mixing roller compacted concrete, transporting, inclined-layer paving, cutting joint, nuclear density testing, applying simultaneously mortar-enriched compact roller concrete at joints of adjacent shuttering, constructions inside the dam and the like, curing and low-temperature protection, furthermore, processing dense treat against the pouring bin surface for the lift range of the rolled concrete, as well as arranging induction joints in the water drawing surface of the dam. Applying the method to the construction of the large volume concrete dam offers advantage of high speed and quality, low cost, durability, and minimum adverse effect due to high or low temperature and rainy weather.

Description

Inclined layer flattening paving method for roller compacted concrete dam construction

The present invention relates to a method of construction of a river dam for a water conservancy project. Specifically, the present invention relates to a sloping layer flat tiling method for damming concrete construction. Background technique

Up to now, the RCC dam construction, which is now commonly used, is called horizontal paving. It is carried out on the horizontal storage surface. If the casting surface is small, the amount of stencil is greatly increased, and the surrounding storage surface is 10 The rim is restrained and the construction speed is reduced because only the large warehouse surface can be poured horizontally. In this way, when the concrete preparation and supply capacity is under a given condition, each paving is laminated, it needs to wait, the time required. As a result, the mechanical properties of the concrete bond layer are thus reduced. Under high temperature or rainfall conditions, it is more prominent, and construction is forced to stop, which is prone to quality accidents. This limits the rapid and economic construction of difficult concrete dams.

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Disclosure of the present invention

The present invention is directed to overcoming the deficiencies in the prior art described above, and to provide a high-rise, high-quality, economical, and large-volume RCC dam construction method.

The object of the present invention can be achieved by the following measures: The process flow of the inclined layer push-pull method, package

20 The direction of the construction of the inclined layer is the same as that of the warehouse. The pouring is 3 - 15 layers, and the thickness of the casting layer is 0.9 - 4. 5m. The amount of 2000 - 90000m ³ , the slope of the slope is 1: 8 - 1: 25 for the lofting, on the foundation rock surface of the dam bank slope, the beginning and the end of the concrete pouring are in the same direction as the construction direction. , the structure, the specified position of the rolling layer of each numbered layer is marked by the surveying; the seam surface is roughed, and the "old" concrete layer before the laying of the sand pad is treated twice, first

25 times, before the planned pouring construction and before the concrete pouring, the 40MPa high-pressure jet water is used for the first time, before the adjacent pouring construction, the area along the horizontal strip of the slope foot, the surface adhesion is removed by the pouring construction. Contaminants, until fresh, dry and anhydrous film state; RCC mixing, transportation, construction level paving mortar, inclined layer paving, inclined layer rolling, horizontal strips of sloped slope feet, front The edge is 30 - 50CD1 as the "side limit", not laminated, the inclined layer rolling and the wheel track overlap 0. 5 - lm, the inclined layer flat push 0 paving method the width of the horizontal strip along the slope front Less than the width of the inclined layer paving, ^ the interval between the construction joints is less than the time of the inclined layer rolling cycle; the closing surface of the RCC pouring construction is close to the dam body and the downstream template is the first vibrating and dense After 90-120min, the coagulation hardening in the construction reaches the correction page (Article 91) When reshaping the state, use the curved wave plate vibrator to vibrate to increase the penetration diameter of the construction joint and improve the tensile mechanical properties. The dam body roller compacted concrete is used for vibration-free rolling and direct slurry to improve the construction joint and compact. To prevent the occurrence of cracks in the dam (especially the upstream dam surface), the artificial boring method is used to form the induction joint before the pouring of the upper layer of RCC, and the stress is set as the drainage hole; The slitting and nuclear density detection are carried out, and at the same time, the slurry is applied to the transition zone between the adjacent formwork, the structure of the dam body and the traditional concrete joint, and the milled concrete is used for the transition zone treatment; and then the health preservation and low temperature protection are carried out until the next pouring lift cycle.

Brief description of the drawing

Figure 1 The process flow of the inclined layer push-pull method.

Fig. 2 Plane diagram of the inclined layer paving method: 1. The extent of the pouring layer, 2. The layer of the inclined layer, 3. The horizontal strip of the inclined slope, 4. The order of the paving strip, 5. The concrete pouring The short side dimensions of the warehouse face gallery, 6. The length dimension of the contour of the concrete pouring bin.

Fig. 3 is a schematic cross-sectional view of the inclined layer paving method: 11. Thickness of the inclined layer, 12. Length of the top surface of a diagonal layer, 13. Slope of the inclined layer level 1: 8 - 1: 25, 14. Construction occupation direction, 15. The height of the lift of the planned concrete placement, 16. The length of the slope of each inclined slope, 17. The top surface (the end surface of the concrete pouring lift), 18. The construction level of the old concrete.

Fig. 4 Schematic diagram of the opening of the oblique layer paving method: 01. The thickness of the inclined layer 02. The length of the top surface of a diagonal layer, the slope of the layer of the inclined layer of 03. 1. 8-1. 25, 04. Construction occupation direction, 05 The height of the lift of the planned concrete pouring, 06. The reserved level of the opening is about 10m, 07. The length of each horizontal slope is <1111, 08. The top surface (the end surface of the concrete pouring lift), 09. Construction level of old concrete.

Fig.5 Schematic diagram of the cross-section of the inclined layer paving method: 21. The thickness of the inclined layer, 22. The length of the top surface of the inclined layer, 23. The slope of the inclined layer layer, 24. The adjacent section of the closing section (or the abutment) The reserved level of the rock face is about 10m long. 25. The height of the lift of the planned concrete pouring. 26. In order to adjust, the pouring area is not getting smaller and smaller, and the plastic bond performance between the laminated layers is required. The abutment rock slope is not required), and the horizontally crushed layer is entrained, 27. the top surface (the end surface of the concrete pouring lift), 28. The construction level of the old concrete.

Fig. 6 Schematic diagram of the lift profile of the dam body: 31. Height of the pouring lift: nxO. 3m (n is a positive integer), 32, 33 adjacent to the upper and lower formwork, vibrating with a curved wave plate vibrating machine, 34. Pressed concrete, 35, 36. Upper and lower rich slurry compacted concrete and dam body RCC interface (Christmas tree effect).

Figure 7 Schematic diagram of the construction of the RCC gravity dam surface: 41. Designed dam body joints, 42. Induced joints (order ab=bc 10m) (moderate area 15m), 43. Stress dry holes, 44. The method of pushing the dam is indicated. Best technical solution for implementing the invention

The inclined layer flat push paving method is used for RCC construction, separate bin stage, normal pouring stage and closing correction page (fine ^Article 91) At the stage, as shown in Figure 4, Figure 3, and Figure 5, the fans of the rationale have been clarified. The construction occupation direction is determined according to factors such as concrete production, supply capacity, dam size and detail structure. For example, under normal temperature conditions, the concrete production capacity is 250m ³ /h. For RCC arch dams or gravity dams up to 100 meters, the best construction plan is to take the longitudinal direction, that is, to open the dam shoulder from the starting point of concrete supply into the dam. And at the beginning of the dam shoulder to close the warehouse. There is no formwork between the dam sections, and the seam is made by a vibrating slitting machine. For high-gravity dams over 100 meters, the dam width is large, and it can be divided vertically and vertically. From the downstream to the upstream, the construction is carried out from one end of the bank slope.

Inclined slope 1: 8-1: 25 variation range is available, based on the strength of the supplied concrete supply (mVh) and the slope is slow; slope 2. 3. ~ 7. 1. The cosine function of the elevation angle is > 99. This indicates that the attenuation of the vibratory rolling function on the level of the inclined layer is slight; it does not damage the concrete mixture against separation.

As we all know, the quality of new and old concrete cement joints on the dam construction level is shown in Figure 3.18, which is the most critical part.

To this end, the present invention particularly emphasizes: First, the application of high pressure (about 40 MPa) spray water blistering treatment as shown in Figure 3.18, as long as the continuous casting time allows, when the roller compacted concrete reaches 20% of the design age strength Beginning to blister, the blistering exposes a good calcium carbonate crystalline film with a firm surface to the concrete without requiring the bulging of the aggregate; because the cementation strength depends on the cement granules rather than the coarse aggregates; second, the concrete is poured Before paving the mortar mat, remove the contaminants from the pouring construction to clean, and become semi-dry, state (if the rain can be blown by compressed air or negative pressure machine to absorb surface water); third, in the treatment Immediately spread the mortar on the surface of the warehouse (the strength of the mortar is greater than the strength of the roller compacted concrete 1 ~ 2), then cover the RCC, and immediately vibrate and compact; Fourth, when the longitudinal construction, the dam body compacted concrete and The upstream self-seepage anti-seepage RCC shall occupy the width of half of the horizontal strips in order to prevent the construction from stalling for a reason, and the weak layers are concentrated and there is little possibility of seepage. Hazard; Fifth, the horizontal strip width of the slope foot should be less than the horizontal width of one inclined layer, that is, Figure 3, 16<12, the purpose is to construct the horizontal strip RCC with less than one inclined layer. Time period. One or more of these measures are beneficial to the compaction of the laminated concrete layer and the mechanical properties of the RCC body.

The inclined layer flat-pushing method requires the process technology of RCC transportation, paving to eliminate the separation of the physical aggregate, and the nuclear density meter detection after the slitting and rolling, and the horizontal paving method: 3⁄4 condensation The earthwork skill is the same, and the inclined layer flat push paving method can intuitively and conveniently carry out the construction work of the construction layer joint without interference, and can ensure that the crushed layer is compacted in a plastic state, and the practice has shown that the compacted layer is compacted. Very little can be detected from the core of the dam.

In recent years, China has first used the solidified compacted concrete for the dam full-section rolling >'Kun concrete construction, which created a very convenient condition. The slurry-grinding RCC is mixed with a correction sheet of about 7% of the cement material (Article 9 1) 93% of the RCC mixture is vibrated with a plug-in vibrator; the cementitious material slurry is mixed with special properties (retardation, durability, anti-seepage, micro-expansion) admixture, the ratio of which is determined by experiment and used High-speed mixing, high-speed mixer (>900rpm) can fully pulverize cement particles, which can slow down sedimentation and coagulation; pipeline pumping for reinforced concrete on the dam, roller compacted concrete construction, roller compacted concrete paving after artificial bottoming The middle and second layers are sprayed with a slurry volume of about 2L/m ² (rolling layer thickness of 0.3m). The concrete is closed and the vibrating compact is dense. The slurry-rich compacted roller compacted concrete is beneficial to the RCC and the dam structure. Upper and lower dam formwork, split joint formwork for splitting, rock face; corridor, well hole, reinforced concrete, etc.) Synchronous pouring lift construction: first vibrating and solidifying compacted RCC and vibrating simultaneously with RCC Rolling, the roller requires 10-20 cm on the tapped and solidified roller compacted concrete. Therefore, the slurry-rich compacted RCC is only required to be paved to a width of 30 cm adjacent to the downstream of the dam; the upstream of the dam is determined according to the designed anti-seepage structure requirements. This constitutes a full-faced RCC building of any shape.

Roller compacted concrete dams are mechanized construction, requiring a small number of manuals to coordinate, dynamic quality management and process requirements for key technical parts. Practice of the Invention ISO9004: 2000 Appendix A Self-Assessment Guide Operational maturity level: "5 best operational level; the strongest comprehensive improvement process; confirm the best results of horizontal comparison." Therefore, the implementation of the inclined layer flat-pushing method and its matching RCC dam construction method guarantees the cementing quality of the seam surface of the construction layer, ensuring that no cracks occur on the dam surface; The construction economy is more economical. The advantages of RCC dam construction: (investment and short construction period) can be fully utilized to replace the traditional concrete dam (1936 US, Hoover dam dam construction method) will become possible. This is the significance and role of the present invention.

Example 1

The inclined layer flat push paving method is used in the performance of Jiangyaoba. If the pouring warehouse surface is 60m X 200m = UOOOm ² , the pouring layer thickness is 3m, and the concrete pouring pouring strength q = 200m ³ -h ^-1 , the horizontal layer and For different slope ratios, the thickness of each layer is 0.3 m, and the slope of the slope is 1: 8 - 1: 25. See Table 1 for the comparison of interlayer intervals.

Table 1 Comparison of interlayer interval time of various paving slope ratios

Slope 1: m, m 25 20 15 10 8

α (° ) 0 (opening level) 2. 29 2. 86 3. 81 5. 71 7. 13

Number of paving layers 10 26 34 45 67 84

4 ί & Build Time per Floor 18: 00 6: 55 5: 24 4: 03 2: 42 2: 10

Inter-layer spacing time comparison 8. 33 3. 20 2. 50 1. 88 1. 12 1. 00

The slope ratios listed in Table 1 have no effect on the mechanical operation performance and concrete properties because the elevation angle ^[艮 is small and the cosine values are above 0.99.

Correction page (fine shell! f section 91) Industrial construction application '|~生

1. Due to the long side of the pouring and pouring face, ', in order to meet the speed of mixing the soil into the warehouse': to determine the slope of the inclined layer, to make the mechanical flow of the rolling warehouse surface, the process is concentrated, high-speed continuous, large The land has increased overall productivity.

2. The quality of RCC is inextricably linked with several time parameters. The inclined layer paving method is the only method that may meet this time requirement. For example, the American Concrete Institute has requested: a. Roller compacted concrete The time from the exit to the completion of the crushing does not exceed 40 minutes.

b. The time from rolling into the grouting concrete mixture does not exceed 10 minutes.

c. The layering material of the layer and the seam surface shall not exceed 15 minutes from paving to covering.

3. The method can be used both horizontally and vertically. Therefore, its rolling layer or construction joint can be inclined to the upstream, which is beneficial to the stability of the dam.

4. The spatial constraints of the construction of the horizontal layer paving method have been changed. The construction preparation, maintenance and quality supervision are intuitive and orderly, and the management is simplified. The large-scale flow operation of the dam is formed, the disturbance of the pouring operation is small, and the construction safety is improved. Degree, increased utilization rate of construction machinery, smooth construction and more rationalization.

5. Simplified the layout of concrete warehousing roads, eliminating the trouble of installing vertical transportation parts, eliminating the construction difficulty and hidden danger of the stencil. - ■· ^ .

6. The interval between floors is reduced. The new and old concrete joints are the key parts of the quality. They account for about the area of the slopes within 1 / 10 of the area of the inclined layer. It is easy to ensure the construction joints with this method. The freshness of the surface pad sand pad is covered with concrete in a very short time without being subjected to the rolling of the construction machine, and compacted and compacted to obtain the most reliable seam surface impermeability and cementing firmness.

7. The method is more suitable for construction under special conditions, such as rainy days, high temperature sunshine or low temperature season construction.

8. On the dam, the downstream rich slurry compaction and the ram body compacted concrete closing surface (ie the horizontal warehouse surface where the lift is terminated), due to the process of vibrating and compacting, the water rises and the air floats to the surface. Residues; the hair-like cracks formed by the indentation of the rolling wheel, the surface concrete fine stone and the vibration grinding frequency resonate and "jump", weakening the close combination with the surrounding concrete mixture, etc., causing the surface layer to be thick The durability of 30-50 face concrete (impregnancy, frost resistance) and mechanical properties (especially tensile strength) are very poor, and it is a key part that jeopardizes the life of the dam (ie, the longest period of maintenance without maintenance). To solve this problem, I propose:

a. Rich slurry compacted RCC, 90-120min after the first vibrating compaction, when the concrete "hardens" to reach the state of "remodeling" (Note: "Remolded" state, vibrate into the 10cm depth with vibrating rod, Vibration for 30 seconds, still can be slurryed within 10cm, and no holes are left.) 1. Apply lkw curve plate vibrator (waveform correction page (fine 3⁄4, 91) 25. 4^25. 4mm, 500 c400 iron plate) vibrate in the longitudinal direction (vertical flow direction) until it is fully flooded. b. On the receiving surface of the roller compacted concrete of the dam, 6G-90rain after the completion of the first vibration rolling, using 1-2 times of vibrationless rolling (slow speed <0.3m/s walking, 1-2 round trip).

9. In order to prevent the vertical boring crack in the dam anti-seepage area, the length of the dam section should be 10m (15πι in the mild area). In order to avoid the smoothness of the roller compaction due to the small dam block, the dam is poured in the upper dam. The construction process is followed by hand-drilling to induce the diameter of the hole 38 legs; terminate the stress relief hole diameter

150-200mm, so that the upper and lower joints have a drainage function, and discharge to the drainage corridor in the dam. For the dam body length of 20m or more, this is very beneficial for the construction of the tamping concrete, but the practice shows that The dam block often causes vertical cracks after several years of slitting. The present invention utilizes the health stop time on the receiving surface, in the large

The slabs of the concrete are poured. The depth of the drill is 0. 7 times the concrete pouring. The diameter of the drilled hole is 38 mm, the spacing is 10 cm, and the drilling depth is 0. 7 times the concrete pouring. Lifting thickness; The diameter of the drilling stress relief hole is 150 mm, the inducing hole is backfilled with drilling slag or dry sand, the stress relief hole is blocked with wooden board, measuring and recording, drilling, connecting the upper and lower, and the bottom is connected with the drainage gallery. To exclude dam seepage water. It satisfies the "seepage control and anti-seepage structure of RCC dam" itself, stable anti-seepage effect, adaptability to deformation, convenient construction and no interference.

10. Comprehensive technical and economic benefits:

a. Comparison of the construction of the inclined layer flattening and the horizontal layer paving method, as shown in Table 2, (taking the performance of Jiangyan dam as an example) the comprehensive construction efficiency:

Comparison of construction speed efficiency of two kinds of roller compacted concrete paving method

* The average of the behavioral statistics on the number; the behavior is the relative ratio of the two paving methods.

The values listed in Table 2 indicate that the inclined layer flat push paving is most suitable for the large warehouse surface at the same lift height. The efficiency of the horizontal layer paving method is 100, and the inclined layer paving method is 143. Table 3, comparison of the flat layer paving method and the inclined layer flat paving method and superiority.

Correction page "Rules 91" b. Economic benefits

Jiangya dam to dam RCC performance, for example, the swash layer placing method than the 30% efficiency level layer paving method, improving economic efficiency RMB26. 40 membered / m ^3, eliminating the need for templates and Gap The economic benefit of the slurry-rich slurry on both sides is RMB 2.30/m ³ .

c. Social benefits

The construction of the river dam water conservancy project is a social basic industry for flood control and disaster mitigation, and the discovery of water conservancy and power resources. The application of this patented technology simplifies the construction process, ensures quality, speeds up the progress, and early exerts the project efficiency, which will certainly produce significant social benefits. .

d. The superiority of the flat-level paving method and the inclined layer flat-pushing method is summarized in Table 3.

Correction page Details ^Article 91)

Claims

Rights request

1. A method for inclined layer paving of RCC dam construction, which is composed of roller compacted concrete mixing, transportation, slitting, nuclear density detection, and at the same time in the vicinity of the board, the structure of the dam body and The traditional concrete transfer site uses a slurry-grinding RCC, a health-care, low-temperature protection, and a process of the next pouring lift, which is characterized by the construction occupation direction of the inclined layer and the length direction of the storage surface. Consistently, pouring 3 - 15 rolling layers, pouring layer thickness 0. 9 - 4. 5m, concrete weight of each lift pouring 2000 - 90000m ³ , slope grade 1: 8 - 1: 25 for stakeout , on the foundation rock face of the dam bank slope, the starting and ending end of the concrete pouring, the lateral formwork and structure in the same direction as the construction direction, and the determined position of each numbered inclined layer rolling is marked by the surveying; The "old" concrete layer before the sand paddle is treated twice. For the first time, before the planned pouring construction and concrete pouring, it is washed with 40MPa high-pressure jet water, twice, before the pouring construction, the horizontal bar along the slope band The area, which removes the surface-attached contaminants caused by the pouring construction; the inclined layer paving, paving and rolling in the inclined layer, wherein the horizontal strip of the inclined slope foot, the front edge leaves 30 - 50cni as the "limit"", not rolling, the inclined layer rolling and the horizontal strip rolling surface overlap 0. 5 - lm, the width of the horizontal strip along the slope before the inclined layer paving construction is less than the width of the oblique layer paving , the interval between the construction joints is less than the time of the paving cycle of the roller compacted concrete; the closing surface of the roller compacted concrete pouring construction, 90-120?nin after the first vibrating compaction, when the concrete hardens to reach the remodeling state The rich pulp vibrating concrete is vibrated by the curved wave plate, and the dam body compacted concrete is pressed with no vibration to the slurry, so that the construction joint of the dam concrete pouring is more compact.

2. The inclined layer flat-pushing method for roller compacted concrete dam construction according to claim 1, characterized in that the health care stop time on the collection surface is used, and the spacing between the dam transverse joints is designed. At 1/2, an artificial drilling method is used to form an induced joint that prevents cracks from occurring on the upstream surface of the dam.

3. The inclined J: flat push paving method for roller compacted concrete dam construction according to claim 2, characterized in that the length of the induced joint is more than 3 meters, and the formation of the induced joint is close to the dam surface. Set the copper water stop parts 1 or more, the drill induction hole diameter is 38 mm, the spacing is 10 cm, the drilling depth is 0.7 times the concrete pouring lift thickness; the drilling stress relief hole diameter is greater than 150 mm, the induction hole is drilled The slag or dry sand is backfilled, and the stress relief hole is sealed with a wooden board to measure the record, drill, make the upper and lower through, and the bottom is connected with the drainage gallery to exclude the dam seepage water.

Correction page (Article 91)