CN110984079B - Construction method of self-compacting concrete rock-fill dam - Google Patents
Construction method of self-compacting concrete rock-fill dam Download PDFInfo
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02B—HYDRAULIC ENGINEERING
- E02B7/00—Barrages or weirs; Layout, construction, methods of, or devices for, making same
- E02B7/02—Fixed barrages
- E02B7/04—Dams across valleys
- E02B7/06—Earth-fill dams; Rock-fill dams
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
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- E02D15/00—Handling building or like materials for hydraulic engineering or foundations
Abstract
The invention relates to a construction method of a self-compacting concrete rock-fill dam, which comprises the following steps: s1 dam face forming; s2 putting rubble stones into a warehouse through an upper dam; s3 self-compacting concrete pumping upper dam: and step S4, pouring the self-compacting concrete into a bin. According to the invention, multiple dimensions such as a rock-fill mode, stone particle size control, concrete water-cement ratio control and a grouting method are optimized, so that the self-compaction filling of concrete can be completed without adding a grouting pipe in the whole construction process, the transportation, rock-fill and irrigation processes can be completed through mechanical equipment, the inserting and distribution of the grouting pipe and the accurate pouring of the grouting pipe are reduced, the flow rate of concrete in a rock-fill body is high, the diffusion is fast, and the construction efficiency of the rock-fill dam is greatly improved.
Description
Technical Field
The invention relates to the technical field of rock-fill dam construction methods, in particular to a self-compacting concrete rock-fill dam construction method.
Background
The rock-fill dam is one kind of earth-rock dam, and is a dam built by filling stone as a main body and matching with an anti-seepage body. The rockfill dam has the advantages of local material utilization, adaptability to various different topographic and geological conditions and climatic conditions, strong capability of resisting high-intensity earthquake and the like, so that the construction and damming technology of the rockfill dam can be rapidly developed.
In the prior art, there are several methods for constructing earth and rockfill dams: 1) the construction method of the concrete dam is constructed by adopting the self-compacting concrete material, and the method is mainly applied to the construction of the dam body structure with a larger concrete seepage-proofing body; 2) the earth-rock dam adopts a composite material to replace concrete to prepare the face plate, the construction process of the composite material face plate is complex, the anti-seepage body needs to be designed to assist in anti-seepage, the construction period is long, and the anti-seepage capability is difficult to ensure; 3) the anti-seepage panel is composed of a glass fiber mortar layer and a glass fiber reinforced plastic layer, and the construction method thereof.
Chinese patent No. CN1238609C discloses a construction method of rock-fill concrete dam, and relates to a technique for applying concrete material with good fluidity and strong material separation resistance to dam construction by using a grouting concrete construction technique and combining with the rock-fill dam construction technique. The method adopts the rock-fill which is not screened or primarily screened, directly puts the coarse aggregate into a bin by utilizing the construction mode of the rock-fill dam, and embeds a grouting pipe at the position where concrete is required to be formed; and then filling the concrete for filling into the gaps of the rock-fill through the pre-buried grouting pipes to form a rock-fill concrete part dam body or the whole dam body.
The above prior art solutions have the following drawbacks: although it has possessed the faster advantage of rock-fill dam construction speed, it needs a large amount of distribution grout pipes in the work progress, and is more to the restriction of construction, mainly shows: 1. the rapid stone stacking by mechanical equipment is difficult to carry out; 2. the depth position and the distribution density of the grouting pipe need strict requirements, otherwise, the problems of small distribution quantity of middle-layer mortar, poor diffusion uniformity of the bottom layer and the like can occur; 3. the grouting is supported by a grouting pipe, and the grouting speed is limited; the above problems all result in the efficiency of the whole construction process not being high enough.
Disclosure of Invention
The invention aims to provide a construction method of a self-compacting concrete rock-fill dam, which achieves the advantage of greatly improving the construction efficiency of the rock-fill dam.
The above object of the present invention is achieved by the following technical solutions:
a construction method of a self-compacting concrete rock-fill dam comprises the following steps:
s1, forming a dam face, namely building the outer contour of the formed dam face by adopting facing stone masonry or a template;
s2 putting the rubble stones into a warehouse through a dam, sending the rubble stones into the chiseled foundation surface, and forming a natural rockfill body by swinging the stones through a backhoe excavator; the volume distribution of the block stones in the bin is large at the bottom and small at the top, large at the middle and small at the outside, rough block stones are pretreated before entering the bin, and the minimum grain diameter of the rough block stones is not less than 30 cm;
s3 self-compacting concrete pumping upper dam: wherein the water-gel ratio of water of the self-compacting concrete to the gel material is controlled within the range of 0.65-0.68;
s4, pouring self-compacting concrete into a bin, pouring the concrete on the dam to a rockfill body, wherein pouring points are uniformly distributed in the pouring process, and the distance between the pouring points is less than 3 m; the pouring sequence is in a unidirectional sequence and can not be poured in a reciprocating mode.
By adopting the technical scheme, the manner of adopting the rockfill with the large bottom, the small top, the large middle and the small outside enables the gaps in the whole rockfill to naturally form the following characteristics, the number of the gaps is gradually reduced from top to bottom, but the sizes of the gaps are gradually increased, the communication rate among the gaps is increased, especially after the particle size of the rubble is controlled to be more than or equal to 30cm, enough flux can be basically kept among all the gaps, on the basis, the water-cement ratio is controlled to be in the range of 0.65-0.68, the fluidity of the concrete can be fully kept in a proper range value on the basis of ensuring the solidification quality, the concrete can smoothly and naturally flow into the gaps of the rockfill under the pouring method of the step S4, the self-compaction filling of the concrete can be completed without adding a grouting pipe in the whole process, and the transportation, the rockfill and the pouring can be completed by mechanical equipment, and the cloth inserting and the accurate pouring of the grouting pipe are omitted, the flow rate of concrete in the rock-fill body is high, the diffusion is fast, and the construction efficiency of the rock-fill dam is greatly improved.
The invention is further configured to: the method for building and forming the external contour of the dam face by adopting the facing stones comprises the following steps: step S1.1, pre-paving mortar with the thickness of a on a foundation surface, building face stones one by one to form the outer contour of a dam surface, wherein the average interval between the horizontally adjacent face stones is b, a = (1.3-1.7) b, the face stones sink to a certain extent after being built, and knocking and shaking by using an iron hammer to enable the seat mortar to overflow and ensure compactness; manually tamping and inserting the mortar in the vertical joint between the facing stones, wherein common tools comprise a steel bar tamping and inserting rod, a bamboo sheet tamping and inserting rod or a tamping and inserting steel plate;
and S1.2, after the one-layer masonry is finished, continuously pre-paving mortar with the thickness of a on the basis of the top surface of the finished layer, and building the upper layer by the same method until the current construction layer of the dam body is set to be high.
By adopting the technical scheme, the occlusion strength between the facing stones can be controlled by controlling the pre-paving thickness of the mortar, but the mortar is weaker in water impact resistance relative to the facing stones after being solidified, and the two strengths can be kept at appropriate performance requirements by limiting the proportion by 1.3-1.7.
The invention is further configured to: in the step S2, before the rubble is put into a bin, the surface of the basic surface needs to be treated, the surface of the basic surface needs to be chiseled and washed, and the rubble is naturally dried after being cleaned; the impact force generated on the basic bin is controlled in the process of putting the rubble stones into the bin so as to avoid causing early damage to the building; in the step S3, the self-compacting concrete is transported to the top of the dam by a transporting device, the self-compacting concrete is transported by a concrete transporting vehicle or pumped by a pressure pump in the horizontal transportation, and the self-compacting concrete is pumped by a pressure pump in the vertical transportation.
By adopting the technical scheme, the bonding strength between the rubble and the foundation surface after rubble stacking and grouting can be effectively improved after the rubble is chiseled; the pressure pump can improve continuous conveying capacity and can conveniently provide vertical conveying.
The invention is further configured to: it is permissible in step S2 to use a small amount of slate but not more than 10% by weight of the total weight of the rockfill material. The rockfill material should be local weakly weathered fresh limestone with a saturated compressive strength (Rs) not less than 40MPa, and should be cleaned before warehousing, and the mud content is not more than 0.5%, and is not allowed to contain mud blocks. The foundation bin and the upper layer of concrete can be put into the bin when the strength of the foundation bin and the upper layer of concrete reaches more than 2.5 MPa.
By adopting the technical scheme, more rubbles can be generated in the process of quarrying and breaking stones, and due to the characteristic of the flaky structure, the particle size structure of the rubbles can not be measured by 30CM completely, namely the whole other sizes exceed 30CM more, but the thickness is possibly less than 30CM, the influence of the rubbles on the gap control of the rockfill body is small, and when the total weight is controlled within 10%, the rockfill body can still keep a proper natural gap.
The invention is further configured to: in step S3, a double horizontal shaft forced mixer is adopted for mixing the self-compacting concrete; feeding the self-compacting concrete in sequence during mixing, firstly putting the weighed aggregate and the gelled material into a mixer respectively for dry mixing for 30s, then adding water and an additive and continuing to stir for 60s, wherein the additive comprises a high-efficiency water reducing agent and an anti-segregation agent; the gel material comprises cement and fly ash, and when the gel material is 30kg, the dosage of the cement is adjusted within the range of 10 kg-20 kg; the using amount of the fly ash is adjusted within the range of 20-10 kg.
By adopting the technical scheme, the double-horizontal-shaft forced mixer can produce a stirring material with partial powder, the flowability of the self-compacting concrete is effectively improved, the dry mixing of the aggregate and the gelled material also aims at improving the crushing property and the mixing uniformity, then water and an additive are added to improve the flowability, and the control of the gelled material is mainly used for keeping the gluing effect.
The invention is further configured to: self-compacting concrete will be comprehensive before mixing and detect the raw and other materials in the place, survey the moisture content of aggregate, mud content, according to the change condition of aggregate moisture content, adjust the water consumption at any time. Wherein the aggregate comprises fine aggregate and coarse aggregate, and the proportion of the fine aggregate and the coarse aggregate is 1: 4; the fine aggregate contains fine powder with the particle size of less than 0.125mm not less than 10 percent, the mud content is not more than 3 percent, the mud block content is not more than 1 percent, and the fine aggregate is selected from artificial sand, natural sand or the combination of the artificial sand and the natural sand which are hard, clean and good in gradation; the fineness modulus of the artificial sand is 2.4-2.8, and the fineness modulus of the natural sand is 2.2-3.0. The water content of the fine aggregate should be kept stable, and the water content of the artificial sand saturated surface is not more than 6%. The coarse aggregate is pebbles, broken stones or broken pebbles which are graded continuously or in 2 single-particle size grades, and the maximum particle size is not more than 20 mm. The mud content of the coarse aggregate cannot exceed 1 percent, and the content of the needle-shaped flaky particles cannot exceed 8 percent; the coarse aggregate porosity should be less than 40%.
Through adopting above-mentioned technical scheme, the aggregate has the effect that improves mobility or drive flow under the circumstances of gravity self-compaction, when the quality requirement restriction of aggregate above-mentioned reference index, can effectual improvement concrete self-compaction effect.
The invention is further configured to: in step S4, small stones can be thrown into the cavity for leveling if the stones on the surface are less after pouring; in order to ensure better bonding of the next bin, the pouring top surface of each bin is provided with a stone corner, and the height of the stone corner is 5-20 cm higher than that of the top surface.
Through adopting above-mentioned technical scheme, the effectual bonding strength who improves between the upper and lower storehouse.
The invention is further configured to: step S5, performing seam face roughening and pouring;
step S6, performance observation is carried out, the volume weight, the porosity and the compactness of the rock-fill concrete are measured, and the dosage proportion of the rock-fill density and the self-compacting concrete of the next layer is controlled according to the detection result;
step S7 maintenance;
and step S8, repeating the steps 1-7 until the dam body is completely constructed.
By adopting the technical scheme, the bonding strength between the rock-fill bodies, between the rock-fill bodies and the dam faces and between the rock-fill bodies and other side surface conjugants is effectively improved, the integral structural strength is kept, and each index of the next bin can be timely adjusted through performance detection so as to implement management and control on each performance index of the whole dam body.
The invention is further configured to: step S1 includes the step S1.3 of erecting a support between the tops of dam faces or between the dam faces and a mountain, hanging an irrigation bag on the support, wherein the bottom of the irrigation bag is through, the bag face of the irrigation bag is provided with a plurality of holes, the aperture of the hole at the lower half part of the bag face is larger than that of the hole at the upper half part, and the total area of the holes at the lower half part is larger than that of the holes at the upper half part; the top of the irrigation bag is provided with an irrigation opening;
in the step S2, the rock is swayed to form a natural rock-fill body and simultaneously naturally cover the irrigation bag so as to leave the irrigation opening and part of the irrigation bag at the top;
when the self-compacting concrete is poured into the warehouse in the step S4, the position of the flushing and pouring bag is located between two adjacent pouring points of the self-compacting concrete according to the pouring sequence, at least two pouring points are arranged between the adjacent flushing and pouring bags at intervals, and after the self-compacting concrete completes pouring of the pouring points at the downstream of the flushing and pouring bags, the concrete is pressed into the flushing and pouring bag through the flushing and pouring port so as to strengthen the compactness of the concrete at the middle lower part.
By adopting the technical scheme, the hung irrigation bag does not influence the natural rockfill of rubble stones, and when in pouring, the irrigation bag is poured after pouring of the front and rear self-compacting concrete pouring points, so that the filling effect can be achieved, the filled concrete is forced to be further compressed through the through hole at the lower part and the opening on the bag surface, and the compactness is improved; and the holes of the lower part of the irrigation bag are larger than the holes of the upper part, so that sufficient conveying pressure can be provided for concrete injection of the lower part.
The invention is further configured to: and S6 performance observation, wherein one test pit is dug when the rockfill concrete is poured at 4000-6000 m for carrying out double-cropping, so as to detect the unit weight and the porosity of the rockfill concrete. Pre-burying a vertically placed steel pipe in the rockfill process of the step S2, pulling out the steel pipe pre-buried in the step S2 after the rockfill concrete is hardened, and observing and evaluating the compactness of the hole to require that the defect area in the hole is less than or equal to 5% of the total area; performing a water injection test on the embedded hole to detect the compactness of the rock-fill concrete embedded hole; and adjusting the dosage proportion of the rockfill density and the self-compacting concrete of the next layer according to the detection result.
By adopting the technical scheme, the volume weight, the porosity and the compactness of the tested rock-fill concrete can be detected in real time, and the dosage proportion of the rock-fill density and the self-compacting concrete of the next layer is controlled according to the detection result; so as to implement management and control on various performance indexes of the whole dam body.
In conclusion, the beneficial technical effects of the invention are as follows:
the multiple dimensions such as a rockfill mode, stone particle size control, concrete water-cement ratio control, a grouting method and the like are optimized, so that self-compaction filling of concrete can be completed without adding a grouting pipe in the whole construction process, the transportation, rockfill and irrigation can be completed through mechanical equipment, the inserting and distribution of the grouting pipe and the accurate pouring of the grouting pipe are reduced, the concrete in a rockfill body has high flow rate and fast diffusion, and the construction efficiency of a rockfill dam is greatly improved;
by controlling the pre-laying thickness of the mortar, the mortar can keep enough structural strength and enough water impact and corrosion resistance;
the self-compacting effect of the concrete is effectively improved by controlling the proportion of the gel material and the aggregate and the performance index.
Drawings
FIG. 1 is a schematic process flow diagram of example 1;
FIG. 2 is a schematic view of self-compacting concrete casting of example 1;
FIG. 3 is a self-compacting concrete pour point profile of example 1;
FIG. 4 is a fly ash performance index requirement table for example 1;
FIG. 5 is a table of the construction mix ratio parameters for compacted concrete according to example 1;
FIG. 6 is a schematic view of self-compacting concrete placement of example 3;
FIG. 7 is a self-compacting concrete pour point profile of example 3.
In the figure, 1, a rock-fill body; 2. self-compacting concrete; 3. dam facing; 4. a support; 5. filling the bag; 6. and (6) casting points.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
step S1, forming the dam face 3, and building and forming the external contour of the dam face 3 by adopting facing stones;
step S1.1, pre-paving mortar with the thickness of a on a foundation surface, building face stones one by one to form the outer contour of a dam face 3, wherein the average interval between the horizontally adjacent face stones is b, a = (1.3-1.7) b, the face stones sink to a certain extent after being built, and knocking and shaking by using an iron hammer to enable the seat mortar to overflow and ensure compactness; manually tamping and inserting the mortar in the vertical joint between the facing stones, wherein common tools comprise a steel bar tamping and inserting rod, a bamboo sheet tamping and inserting rod or a tamping and inserting steel plate;
s1.2, after the completion of the first layer of masonry, continuously pre-paving mortar with the thickness of a on the basis of the top surface of the completed layer, and building an upper layer by the same method until the set height of the current construction layer of the dam body is generally 2.0 m;
step S2, putting rubble stones into a warehouse through an upper dam:
and S2.1, performing surface treatment on the base surface, namely roughening and washing the surface of the base surface, and naturally drying after cleaning.
S2.2, sending the rubble into the chiseled base surface, and forming a natural rockfill body 1 by swinging the rubble with a backhoe excavator; the volume of the rock blocks in the bin is distributed into a large lower part and a large middle part, the rock piles with larger grain diameters are arranged at the middle lower part of the bin surface, and the rock piles with smaller grain diameters are arranged at the middle upper part of the bin surface, so that the quality of the surface layer is not influenced. And a vertically placed steel pipe is pre-buried in the rockfill process.
The rough stone materials are pretreated before warehousing, the minimum grain diameter is not less than 30cm, the maximum grain diameter is limited by the convenience of transportation and warehousing and is not more than 1.0m, and a small amount of stones are allowed to be used but the weight of the stones is not more than 10 percent of the total weight of the rockfill materials. The rockfill material should be local weakly weathered fresh limestone with a saturated compressive strength (Rs) not less than 40MPa, and should be cleaned before warehousing, and the mud content is not more than 0.5%, and is not allowed to contain mud blocks. The foundation bin and the upper layer of concrete can be put into the bin when the strength of the foundation bin and the upper layer of concrete reaches more than 2.5 MPa. The impact force generated on the basic bin is controlled in the process of putting the rubble stones into the bin, so that early damage to buildings is avoided.
Step S3 self-compacting concrete 2 pump dam up:
and S3.1, mixing the self-compacting concrete 2 on site, wherein the mixing proportion is the basis for mixing the self-compacting concrete 2, so that after the site sand-gravel production system operates stably, raw materials are selected to complete a mixing proportion test. After the mixing proportion of the test room is achieved, a proper field is selected to implement the test block on the field, and all performances of the self-compacting concrete 2 are comprehensively verified.
The self-compacting concrete 2 is mixed by a double horizontal shaft forced mixer. When the self-compacting concrete 2 is mixed, materials are sequentially fed, firstly, weighed aggregates and gelled materials are respectively put into a stirrer to be dry-mixed for 30s, then, water and additives are added to be continuously stirred for 60s, wherein the additives comprise a high-efficiency water reducing agent and an anti-segregation agent. Wherein the dosage of the sandstone can be adjusted within the range of +/-5 percent, the cementing material comprises cement and fly ash, when the dosage of the cementing material is 30kg, the dosage of the cement is adjusted within the range of 10 kg-20 kg, and the cement is preferably portland cement; the use amount of the fly ash is adjusted within the range of 20-10 kg, but the water-glue ratio is controlled within the range of 0.65-0.68. Self-compacting concrete 2 will be comprehensive before mixing and detect the raw and other materials in the place, survey the moisture content of aggregate, mud content, according to the change condition of aggregate moisture content, adjust the water consumption at any time. Wherein the aggregate comprises fine aggregate and coarse aggregate, and the proportion of the fine aggregate and the coarse aggregate is 1: 4; the fine aggregate contains fine powder with the particle size of less than 0.125mm not less than 10 percent, the mud content is not more than 3 percent, the mud block content is not more than 1 percent, and the fine aggregate is selected from artificial sand, natural sand or the combination of the artificial sand and the natural sand which are hard, clean and good in gradation; the fineness modulus of the artificial sand is 2.4-2.8, and the fineness modulus of the natural sand is 2.2-3.0. The water content of the fine aggregate should be kept stable, and the water content of the artificial sand saturated surface is not more than 6%. The coarse aggregate is pebbles, broken stones or broken pebbles which are graded continuously or in 2 single-particle size grades, and the maximum particle size is not more than 20 mm. The mud content of the coarse aggregate cannot exceed 1 percent, and the content of the needle-shaped flaky particles cannot exceed 8 percent; the coarse aggregate void content is preferably less than 40%.
And S3.2, conveying the prepared self-compacting concrete 2 to the top of the dam face 3 by adopting conveying equipment, wherein the concrete is conveyed by adopting a concrete truck or pumped by adopting a pressure pump in horizontal conveying, and the self-compacting concrete is conveyed by adopting a pressure pump in vertical conveying.
Step S4, pouring the self-compacting concrete 2 into a bin, pouring the concrete on the dam to the rockfill 1, wherein pouring points are uniformly distributed in the pouring process, and the distance between the pouring points is less than 3 m; the pouring sequence is in a unidirectional sequence and can not be poured in a reciprocating mode. After pouring is finished, if the surface of the stone block is less, small stone blocks can be thrown in for leveling; in order to ensure better bonding of the next bin, the pouring top surface of each bin is provided with a stone corner, and the height of the stone corner is 5-20 cm higher than that of the top surface. The pouring and warehousing can be realized by pumping, an excavator bucket, a chute, a tank crane and the like.
And S5, brushing the joint surface, wherein the joint surface needs to be washed clean before the horizontal construction joint is poured, and the next layer of concrete can be poured. If floating slurry appears, the slurry is washed clean by high-pressure water before initial setting, and then the next construction procedure can be carried out.
And S6 performance observation, wherein one test pit is dug when the rockfill concrete is poured at 4000-6000 m for carrying out double-cropping, so as to detect the unit weight and the porosity of the rockfill concrete. After the rock-fill concrete is hardened, pulling out the steel pipe pre-embedded in the step S2, and observing and evaluating the compactness of the hole to require that the defect area in the hole is less than or equal to 5% of the total area; performing a water injection test on the embedded hole to detect the compactness of the rock-fill concrete embedded hole; and controlling the dosage proportion of the rockfill density and the self-compacting concrete 2 of the next layer according to the two detection results.
And step S7, performing curing, namely starting watering curing within 6-18 hours after the rockfill concrete is poured, watering in advance under the hot and dry weather conditions, and setting a self-flowing water pipe to form a water jacket method for curing in high-temperature seasons for accelerating the heat dissipation of the surface of the concrete.
And step S8, repeating the steps 1-7 until the dam body is completely constructed.
The performance index of the admixture is in accordance with the relevant regulations in concrete admixture (GB/T8076-2008) and hydraulic concrete admixture technical regulation (DL/T5100-1999), the admixture has the performances of high water reducing rate, small slump loss of concrete mixture, capability of improving concrete shrinkage and the like, and meets the requirements of large fluidity and good cohesiveness of special self-compacting concrete 2.
The performance index of the fly ash is shown in figure 4, and the parameter table of the self-compacting concrete construction mix proportion is shown in figure 5.
The implementation principle of the embodiment is as follows: the method comprises the steps of naturally stacking the rock blocks meeting certain particle size requirements on a bin surface, and pouring special self-compacting concrete meeting the requirements on the surface of a rock pile body, wherein the special self-compacting concrete can fill the gaps of the rock pile body without vibrating and only depends on the self weight of the special self-compacting concrete to form complete and compact concrete.
Example 2: the difference from the embodiment 1 is that the template forming in the step S1 adopts a steel template, a wood template and the like to build the external outline of the dam face, wherein the steel template is made of Q235 steel or 16Mn steel, and the thickness of the face plate is more than or equal to 4 mm; the material of the wood template panel is higher than that of II and the like, and the thickness of the panel is more than or equal to 4 cm. Because the self-compacting concrete has high fluidity and the template has good sealing property, sealing strips need to be pasted at the joints of the template to prevent slurry leakage. Meanwhile, the special self-compacting concrete has high flowability, and the side pressure of the template is also high. Therefore, the formwork must be erected to ensure stability, and the rigidity and the strength of the formwork must be capable of resisting the lateral pressure generated by the self-compacting concrete, and the actual calculation is carried out according to 2.5 times of water pressure.
Example 3: as shown in fig. 6 and 7, the difference from embodiment 1 is that step S1 includes step S1.3 of erecting a support 4 between the tops of the dam faces or between the dam faces and the mountain, hanging an irrigation bag 5 on the support 4, wherein the bottom of the irrigation bag 5 is through, and the bag face of the irrigation bag 5 is provided with a plurality of holes, the hole diameter of the lower half of the bag face is larger than the hole diameter of the upper half, and the total area of the lower half of the holes is larger than the total area of the upper half of the holes; the top of the irrigation bag 5 is provided with an irrigation opening.
The rock is rocked in step S2 to form a natural rock-fill body and also naturally cover the irrigation bag 5 to leave the irrigation opening and a top portion of the irrigation bag 5.
When the self-compacting concrete is poured into the warehouse in the step S4, the position of the flushing and pouring bag 5 should be located between two adjacent pouring points 6 of the self-compacting concrete according to the pouring sequence, and at least two pouring points 6 are spaced between the adjacent flushing and pouring bags 5, after the self-compacting concrete completes the pouring of the pouring points 6 at the downstream of the flushing and pouring bag 5, the concrete is pressed into the flushing and pouring bag 5 through the flushing and pouring opening, so as to strengthen the compactness of the concrete at the middle lower part.
And step S6, after the concrete is hardened, cutting off the irrigation bags 5 above the top layer of the rock-fill concrete.
The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.
Claims (8)
1. A construction method of a self-compacting concrete rock-fill dam is characterized by comprising the following steps: the method comprises the following steps:
s1, forming the dam face (3), and building the outer contour of the formed dam face (3) by facing stone masonry or a template; erecting a support (4) between the tops of dam faces or between the dam faces and a mountain, hanging an irrigation bag (5) on the support (4), wherein the bottom of the irrigation bag (5) is communicated, a plurality of holes are formed in the bag face of the irrigation bag (5), the aperture of the hole in the lower half part of the bag face is larger than that of the hole in the upper half part, and the total area of the holes in the lower half part is larger than that of the holes in the upper half part; the top of the irrigation bag (5) is provided with an irrigation opening;
s2, putting the rubble stones into a warehouse through a dam, sending the rubble stones into the chiseled foundation surface, and forming a natural rockfill body (1) by swinging the stones through a backhoe excavator; the volume distribution of the block stones in the bin is large at the bottom and small at the top, large at the middle and small at the outside, rough block stones are pretreated before entering the bin, and the minimum grain diameter of the rough block stones is not less than 30 cm; forming a natural rock-fill body by the rock swinging, and naturally covering the irrigation bag (5) to leave the irrigation opening and a part of the irrigation bag (5) at the top;
step S3 self-compacting concrete (2) is pumped into the dam: wherein the water-gel ratio of water of the self-compacting concrete (2) to the gel material is controlled within the range of 0.65-0.68;
s4, pouring the self-compacting concrete (2) into a bin, pouring the concrete on the dam to the rockfill (1), wherein pouring points are uniformly distributed in the pouring process, and the distance between the pouring points is less than 3 m; the back of the previous pouring point is required to be filled with the concrete, the concrete can be moved to the next pouring point, and the pouring sequence is in a one-way sequence and can not be poured in a reciprocating manner; when the self-compacting concrete is poured into a warehouse, the position of the flushing and pouring bag (5) is positioned between two adjacent pouring points (6) of the self-compacting concrete according to the pouring sequence, at least two pouring points (6) are spaced between the adjacent flushing and pouring bags (5), and after the self-compacting concrete completes pouring of the pouring points (6) at the downstream of the flushing and pouring bag (5), the concrete is pressed into the flushing and pouring bag (5) through a flushing and pouring opening so as to strengthen the compactness of the concrete at the middle lower part;
step S5, performing seam face brushing and pouring;
s6 performance observation, namely measuring the volume weight, porosity and compactness of the rock-fill concrete, and controlling the dosage proportion of the rock-fill density and the self-compacting concrete (2) of the next layer according to the detection result; after the concrete is hardened, cutting off the irrigation bag (5) above the top layer of the rock-fill concrete;
step S7 maintenance; watering and curing are started within 6-18 h after the rockfill concrete is poured, watering is carried out in advance under the hot and dry weather conditions, and in high-temperature seasons, in order to accelerate the heat dissipation of the surface of the concrete, a self-flowing water pipe is arranged to form water jacket curing;
and step S8, repeating the steps 1-7 until the dam body is completely constructed.
2. The self-compacting concrete rock-fill dam construction method of claim 1, characterized in that: the external contour of the dam face (3) built by facing stones comprises the following steps: step S1.1, pre-paving mortar with the thickness of a on a foundation surface, building face stones one by one to form the outer contour of a dam surface (3), wherein the average interval between the horizontally adjacent face stones is b, wherein a = (1.3-1.7) b, the face stones sink to a certain extent after being built, and knocking and shaking by an iron hammer are applied to enable the seat mortar to overflow and ensure compactness; manually tamping and inserting the mortar in the vertical joint between the facing stones, wherein common tools comprise a steel bar tamping and inserting rod, a bamboo sheet tamping and inserting rod or a tamping and inserting steel plate;
and S1.2, after the one-layer masonry is finished, continuously pre-paving mortar with the thickness of a on the basis of the top surface of the finished layer, and building the upper layer by the same method until the current construction layer of the dam body is set to be high.
3. The self-compacting concrete rock-fill dam construction method of claim 1, characterized in that: in the step S2, before the rubble stones are put into the bin, the surface of the base surface needs to be treated, the surface of the base surface needs to be chiseled and washed, and the rubble stones are naturally dried after being cleaned; the impact force generated on the basic bin is controlled in the process of putting the rubble stones into the bin so as to avoid causing early damage to the building; in the step S3, the prepared self-compacting concrete (2) is conveyed to the top of the dam face (3) by adopting conveying equipment, the concrete is conveyed by adopting a concrete truck or pumped by adopting a pressure pump in horizontal conveying, and the self-compacting concrete is conveyed by adopting a pressure pump in vertical conveying.
4. The self-compacting concrete rock-fill dam construction method of claim 1, characterized in that: in step S2, it is allowed to use a small amount of stone chips but the weight of the stone chips should not exceed 10% of the total weight of the rockfill material; the rockfill material should be selected from local weakly weathered fresh limestone materials, the saturated compressive strength (Rs) of the rockfill material is not less than 40MPa, the rockfill material should be cleaned before warehousing, the mud content is not more than 0.5%, and mud blocks are not allowed to be contained; the foundation bin and the upper layer of concrete can be put into the bin when the strength of the foundation bin and the upper layer of concrete reaches more than 2.5 MPa.
5. The self-compacting concrete rock-fill dam construction method of claim 1, characterized in that: in the step S3, a double horizontal shaft forced mixer is adopted for mixing the self-compacting concrete (2); feeding the self-compacting concrete (2) in sequence during mixing, firstly putting the weighed aggregate and the gelled material into a mixer respectively for dry mixing for 30s, then adding water and an additive for continuously stirring for 60s, wherein the additive comprises a high-efficiency water reducing agent and an anti-segregation agent; the gel material comprises cement and fly ash, and when the gel material is 30kg, the dosage of the cement is adjusted within the range of 10 kg-20 kg; the using amount of the fly ash is adjusted within the range of 20-10 kg.
6. The self-compacting concrete rock-fill dam construction method of claim 5, characterized in that: before the self-compacting concrete (2) is mixed, raw materials in a field are comprehensively detected, the moisture content and the mud content of aggregate are measured, and the water consumption is adjusted at any time according to the change condition of the moisture content of the aggregate; wherein the aggregate comprises fine aggregate and coarse aggregate, and the proportion of the fine aggregate and the coarse aggregate is 1: 4; the fine aggregate contains fine powder with the particle size of less than 0.125mm not less than 10 percent, the mud content is not more than 3 percent, the mud block content is not more than 1 percent, and the fine aggregate is selected from artificial sand, natural sand or the combination of the artificial sand and the natural sand which are hard, clean and good in gradation; the fineness modulus of the artificial sand is 2.4-2.8, and the fineness modulus of the natural sand is 2.2-3.0; the water content of the fine aggregate should be kept stable, and the water content of the artificial sand saturated surface is not more than 6%; the coarse aggregate adopts continuous grading or 2 single-particle size grading pebbles, broken stones or crushed pebbles, and the maximum particle size is not more than 20 mm; the mud content of the coarse aggregate cannot exceed 1 percent, and the content of the needle-shaped flaky particles cannot exceed 8 percent; the coarse aggregate porosity should be less than 40%.
7. The self-compacting concrete rock-fill dam construction method of claim 1, characterized in that: in the step S4, if the surface stones are less after the pouring is completed, small stones can be thrown into the surface stones for leveling; in order to ensure better bonding of the next bin, the pouring top surface of each bin is provided with a stone corner, and the height of the stone corner is 5-20 cm higher than that of the top surface.
8. The self-compacting concrete rock-fill dam construction method of claim 1, characterized in that: step S6, performing performance observation, namely digging one test pit every time 4000-6000 m of pouring of the rock-fill concrete is performed to detect the volume weight and porosity of the rock-fill concrete; pre-burying a vertically placed steel pipe in the rockfill process of the step S2, pulling out the steel pipe pre-buried in the step S2 after the rockfill concrete is hardened, and observing and evaluating the compactness of the hole to require that the defect area in the hole is less than or equal to 5% of the total area; performing a water injection test on the embedded hole to detect the compactness of the rock-fill concrete embedded hole; and controlling the dosage proportion of the rockfill density and the self-compacting concrete (2) of the next layer according to the two detection results.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1238609C (en) * | 2003-02-14 | 2006-01-25 | 清华大学 | Construction method for rock-fill concrete dam |
| CN101074560A (en) * | 2007-06-08 | 2007-11-21 | 清华大学 | Method for constructing normal piled concrete |
-
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- 2019-12-20 CN CN201911321457.1A patent/CN110984079B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1238609C (en) * | 2003-02-14 | 2006-01-25 | 清华大学 | Construction method for rock-fill concrete dam |
| CN101074560A (en) * | 2007-06-08 | 2007-11-21 | 清华大学 | Method for constructing normal piled concrete |
Non-Patent Citations (5)
| Title |
|---|
| 堆石混凝土施工技术应用研究;王韶华等;《人民长江》;20190628;第173-177页 * |
| 福建砌石拱坝施工技术与经济分析;曾金水;《水利水电科技进展》;20020430;第14-17页 * |
| 自密实堆石混凝土在恒山水库除险加固工程中的应用;杨会峰;《山西水利科技》;20100930;第54-55、58页 * |
| 自密实混凝土堆石坝坝体浇筑专项方案（经专家评审通过的）;龙凤呈祥;《豆丁》;20191208;第1-26页 * |
| 龙凤呈祥.自密实混凝土堆石坝坝体浇筑专项方案（经专家评审通过的）.《豆丁》.2019,第1-26页. * |
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