The rock-fill concrete dam construction method
The present invention relates to a kind of dam construction method, particularly a kind of process that adopts good fluidity and strong concrete material, intrusion concrete construction technology and the combination of rock-fill dam construction technology of anti-material separation property to apply to dam construction.
Dam concrete just should reduce cement consumption because its large volume will reduce the concrete heat of hydration and cost as far as possible as far as possible.Generally speaking, adopt big particle diameter aggregate can play such effect, therefore, dam concrete often adopts level Four to join at present, and maximum aggregate size can reach 15cm.If conventional concrete adopts bigger aggregate, in work progress, be subjected to the ability of mixing and stirring, the restriction of the ability of vibrating, relatively difficulty.
Loose rock dam are as a kind of common dam type, and the common work progress that rolls loose rock dam is at present: from the stock ground borrow, utilize the automobile transportation directly to go up the dam, utilize heavy vibrating roller to roll then and make rockfill reach the design compactness.Its working procedure is easy, and the dam body cost is low.But the volume ratio concrete dam of loose rock dam is big, and particularly general loose rock dam all can not be crossed water, need flood spillway be set separately, increase a large amount of construction costs.In addition, the antiseepage body of loose rock dam is as adopting earth core, and then construction is disturbed greatly, is subjected to climatic effect, also causes the core-wall cracking because of non-homogeneous sedimentation easily.Yet there are a lot of problems in the reinforced concrete face rockfill dam that develops rapidly in recent years, the anticracking of panel.
Available coagulation soil dam construction method has following two kinds: column job practices and grinding concrete construction method.
Traditional cylinder method construction cooperates temperature control measures to carry out with block placement, and this method has obtained using widely in the construction of concrete dam.As early stage U.S.'s Hu Buddhist concrete gravity arch dam and present Chinese Three Gorges concrete gravity dam.This form of construction work remains present modal dam concrete construction mode guaranteeing to have obtained a lot of experiences aspect concrete construction quality and the control concrete cracking.But this traditional concrete construction needs a large amount of templates, and buries multiple temperature control measures such as cooling water pipe in needing, and operation is many, the cost height, and speed of application is lower.
The grinding concrete construction method is that eighties of last century the seventies U.S. professor Raphael proposes (Raphael, M., " Theoptimum gravity dam ", Proceedings of Conference on Rapid Construction of ConcreteDams, Asilomar, 1970), this method adopts the no slump concrete and the vibroroller cmpacting technology of zero slump, and speed of application is fast, and temperature control measures is simplified, it is fast to have speed, the advantage that cost is low.Adopt the dam of roller compacted concrete more and more, built up the rolled concrete arch dam high above 100m (sub-arch dam of crossdrift and husky board arch dam) in China, the imperial beach Compacted Concrete Gravity Dam Section height of dam that is putting into operation more surpasses 200m.But roller compacted concrete interlayer in conjunction with relative thin a little less than, particularly because speed is fast, temperature control is simplified, in dam construction later stage and operation early stage, concrete temperature is still higher, the crack takes place in this stage in existing part engineering, need repair.Though these are because the crack that temperature load causes mainly is because the cement consumption of roller compacted concrete is lower than conventional concrete,, the heat of hydration of roller compacted concrete still has sizable amount.Employings such as present rolled concrete arch dam induce structural measures such as seam, structural joint to reduce the risk of cracking, but the complexity of constructing increases.
By the intrusion concrete construction technology that U.S. Weltz proposes, extensive use in constructions such as mole, bridge bridge pier.Intrusion concrete (Prepacked Concrete) is will to be filled in the template storehouse through the coarse aggregate of screening earlier, inject the coarse aggregate space and form concrete with special mortar again, be also referred to as prepackaged concrete (Preplaced AggregateConcrete).Its proposition is based on a kind of Admixture that helps the filling agent that is called, and has improved the flowability of mortar, and in the concrete, this flowability more is guaranteed under water.In the intrusion concrete construction, key is the separation that prevents the perfusion mortar material, guarantees normal mortar is sent in the space of coarse aggregate.
The construction of intrusion concrete has dual mode, and first kind is called placement layer by layer, promptly fills coarse aggregate earlier, carries out mortar injection thereafter to the surface, forms constuction joint, then the constuction joint surface is handled, and fills next storehouse coarse aggregate again, carries out repeatedly.The second way is called horse base nanogram mode owing at first use in horse base nanogram bridge engineering, promptly fill coarse aggregate earlier, carry out mortar injection then, but only be filled into the following certain elevation in surface, in the inner seam that forms of coarse aggregate, this joint face is not handled.Because the mutual interlock of coarse aggregate also has good mechanical property.Japanese building association had just formulated " the construction guide of intrusion concrete " in 1966, after the revision in 1974, merged to " clear and 49 years version concrete standard standards ".
Intrusion concrete is owing to use mortar material to pour in a large number, and cement consumption is big, the material cost height, and the heat of hydration is big, thereby never is applied in dam construction up to now.
Self-compacting concrete (Self-Compacting Concrete), high flowing concrete, self-leveling concrete are good fluidity and the strong concrete of anti-material separation property.As self-compacting concrete is under the help of new and effective water reducing agent, obtain mobile splendid concrete, not needing to vibrate, (imperial palace is refined rich for the effect that just can reach self-compaction, Current conditions ofself-compacting concrete in Japan, " Proceeding of the Second InternationalSymposium on Self-Compacting Concrete ", 63-68,2001.).Self-compacting concrete is difficult for generating material and separates, and bleeding is very little, can not produce newborn cortex at concrete surface, and is therefore, new, old concrete contact surface switching performance is good, does not need special the processing just can reach good effect.In addition, this concrete intensity is also higher, and reasonable combination property is arranged, so, also claim high performance concrete (Super Quality Concrete).Japan building association has published the design of high performance for concrete structure and construction guide rule (Japanese building association, " self compacting high strength degree high durability concrete structure design construction guide rule ", (Japanese) 2001), self-compacting concrete is adopted at the position that is difficult for vibrating in the prefabricated gallery of dam joint portion etc. comprehensively, all adopts this technology as dams such as rivers, three Room.In addition, this has also adopted high performance concrete in suspension bridge of span maximum (main span 1991m) engineering in the world in Japanese alum strait Bridge, and side's amount reaches 290,000 m
3, the duration shortened to 2 years from 2.5 years.But same owing to use more cement and high efficiency water reducing agent to cause it on the high side, the heat of hydration is bigger, does not also use the precedent that self-compacting concrete is built the bed rearrangement dam in the world.
Summary of the invention
At the deficiencies in the prior art and defective, the purpose of this invention is to provide a kind of rock-fill concrete dam construction method, this method can effectively reduce cement consumption, it is many to overcome traditional operation that dam concrete construction caused, cost height, the defective that speed of application is lower, and can effectively reduce the concrete heat of hydration, have that technology is simple, thermal insulation warming is little, reduce construction link, accelerate characteristics such as speed of application.
The objective of the invention is to be achieved through the following technical solutions: a kind of rock-fill concrete dam construction method, this method comprises the steps:
(1) adopts without screening or the preliminary enrockment that sieves, utilize the form of construction work of loose rock dam that coarse aggregate is directly put in storage, and form concrete position pre-embedment grouting pipe at needs;
(2) good fluidity and the strong concrete of anti-material separation property are filled into by pre-embedment grouting pipe in the space of enrockment, form rock-fill concrete part or whole dam body.
In the present invention, when rock-fill concrete is in face edge, storehouse, template need be set at first in the described step (1), can on template, reserve the grouting mouth, again coarse aggregate be put in storage.
The present invention applies to dam construction with good fluidity and strong concrete material (as self-compacting concrete, high flowing concrete, self-leveling concrete), intrusion concrete technology and the combination of rock-fill dam construction technology of anti-material separation property, good fluidity that is adopted and the strong concrete material of anti-material separation property can be preferably self-compacting concrete, it is inserted the dam rockfill that adopts the rock-fill dam construction technology to form, obtain rock-fill concrete, just can realize a kind of new dam concrete construction mode, be called the rock-fill concrete dam construction method.Rock-fill concrete can be used as concrete core-wall or concrete dam body in dam.The coarse aggregate of rock-fill concrete dam directly adopts the enrockment without screening or preliminary screening, promptly adopt the mode that rolls loose rock dam that coarse aggregate is directly put in storage, the concrete that adopts the form of construction work of intrusion concrete to utilize pre-buried grout pipe will be used for filling then is filled into the space of enrockment, forms rock-fill concrete.Therefore can use the aggregate of bigger particle diameter, reach the effect that further saving cement reduces cost.Because technology is simple, reduced construction link, greatly the reduction of erection time simultaneously.
Adopt major advantage of the present invention as follows:
1. the coarse aggregate of rock-fill concrete adopts enrockment, and particle diameter is big, and used cement amount is little in the unit volume concrete, and therefore, cost is low, can effectively reduce the concrete thermal insulation warming simultaneously, simplifies temperature control measures.
2. only need mix and stir the concrete of small particle diameter, batching plant reduces greatly, and does not need vibrator to vibrate, and has simplified concrete construction process.If the employing coarse fraction, big aggregate is directly gone up the dam and is rolled, and little aggregate can be used for producing concrete aggregate and the sand that is used for filling, can make full use of material.
3. the concrete process of building mainly contains rockfill and rolls and two processes of concrete filling, and the former and earth and rockfill dam construction are approximate, and the latter does not need to vibrate, and operation is simplified, and can accelerate speed of application.This also is crucial advantage in Dam Construction.
4. for ungetable job site, because it is high to transport the unit price of cement, the rock-fill concrete dam construction method of therefore significantly saving cement has great advantage in this type of place.
Description of drawings:
Fig. 1 is a rock-fill concrete dam construction method schematic diagram.
Fig. 2 is one of embodiment of the present invention: rock-fill concrete core wall rockfill dam job practices schematic diagram.
Fig. 3 is two of an embodiment of the present invention: rock-fill concrete mixed dam job practices schematic diagram.
Fig. 4 is three of an embodiment of the present invention: enrockment coagulation gravity dam or job practice of arch dam schematic diagram.
The specific embodiment
Further specify embodiments of the present invention below in conjunction with drawings and Examples:
The present invention is on the basis of existing technology, good fluidity and strong self-compacting concrete material, intrusion concrete technology and the combination of rock-fill dam construction technology of anti-material separation property are applied to dam construction, employing is without the enrockment 3 of screening or preliminary screening, utilize the form of construction work of loose rock dam that coarse aggregate is directly put in storage, and form concrete position pre-embedment grouting pipe 2 at needs; Then self-compacting concrete 1 is filled into by pre-embedment grouting pipe in the space of enrockment, forms rock-fill concrete part or whole dam body.When rock-fill concrete is in face edge, storehouse, template 4 need at first be set, again coarse aggregate 3 is put in storage.
Embodiment 1: the form of construction work of rock-fill concrete core wall rockfill dam
As shown in Figure 2, in traditional loose rock dam, adopt rock-fill concrete core-wall 8, build the rock-fill concrete core wall rockfill dam as the antiseepage body.
At first, fill upstream dam body 6 and downstream dam body 7 according to will seeking unification of loose rock dam, but in the process of filling, bury grout pipe 2 underground at the core-wall position, after dam embankment arrives certain construction bed thickness 5, utilize these grout pipes 2 to carry out the rock-fill concrete construction, form the rock-fill concrete core-wall.This form of construction work can be constructed without template 4 fully.Mobile the stop back of self-compacting concrete 1 in rockfill forms the rock-fill concrete core-wall automatically.Seam can adopt horse base nanogram mode to construct.
Embodiment 2: the form of construction work of rock-fill concrete mixed dam
At dam upstream side shuttering 4, at first carry out rockfill 3 and fill, carry out the rock-fill concrete construction at upstream side then, form concrete guard wall 9 at upstream side, simultaneously as the antiseepage body, see Fig. 3.If dam is higher, the thickness of upstream side concrete guard wall 9 is bigger, not only needs the 4 grouting mouth perfusion self-compacting concretes of reserving from template side, upstream, also needs to pour into from top pre-embedment grouting pipe 2.
Because what adopt is the rock-fill concrete construction, the mutual interlock of aggregate of upstream side gravity barricade 9 and downstream rockfill 7 helps the The combined effect under the hydraulic action of upstream.
This dam type is compared with the rock-fill concrete core wall rockfill dam, because upstream side is a concrete gravity formula barricade, the cumulative volume of dam body significantly reduces, and can reduce cost and accelerating construction progress.In addition, the easy detection of the construction quality of upstream side gravity barricade also is an advantage.This construction application need be provided with template 4 at upstream face.
Embodiment 3: rock-fill concrete gravity dam or arch dam construction mode
In order further to reduce the dam body volume, the mode that can also adopt full section to inject self-compacting concrete 1 is built rock-fill concrete gravity dam or arch dam, forms full section rock-fill concrete, sees Fig. 4.This construction need be provided with template 4 at the upstream and downstream face.Because cement is few in the dam rock-fill concrete, thermal insulation warming is low, can be on the basis of temperature control measures such as control dam self-compacting concrete 1 implantation temperature, do not bury cooling water pipe underground, carry out concreting without longitudinal joint, can on the basis of saving cost, reach the purpose of rapid construction like this.In addition and the combination of rock-fill concrete mixed dam, in a key water control project, adopt the rock-fill concrete mixed dam as the dash monolith, adopt the rock-fill concrete gravity dam as the overflow monolith, can realize the dam body flood discharge, the superiority that makes this dam type is obtained bigger performance.