CN1076234A - Prevent the method for frost crack of irrigation ditch with rigid facing - Google Patents

Abstract

A kind of method that prevents frost crack of irrigation ditch with rigid facing.It is that loose heat insulating materials such as swelling perlite powder are seated in the plastic flexible pipe, constitutes insulation tunic pipe.The film pipe is laid on below the rigid facing.To be prevented the purpose that canal frost heave destroys.This method good freezing protection effect, material is easy to get, only 9.35 yuan of every construction cost per square meters, and be convenient to construction.

Description

Prevent the method for frost crack of irrigation ditch with rigid facing

A kind of method that prevents frost crack of irrigation ditch with rigid facing.

Cold district, the frost heaving failure problem of rigid facing channel is very serious.At present, solve this difficult problem with following several method both at home and abroad: 1. adopt and increase the weight of and strengthen the rigid facing channel structure, change the section of channel.This method is difficult to the purpose that reaches freeze proof effectively.2. the moisture soil body under the rigidity mask is taked the insulation measure; As do not lay all good polystyrol plastic foam plate of waterproof and heat-insulating property at rigid facing.This method antifreezing effect is better, but it involves great expense, and every cubic metre of cost is at 385 yuan, so be difficult in practical engineering application.Some area proposes to lay the purpose that heat insulating materials such as lower hydrophobic pearlite warming plate of coefficient of thermal conductivity and waterproof thermal-insulated mineral wool board reach frost heaving resistant destruction under rigid facing in recent years, this method can reduce cost 1/3rd than polystyrol plastic foam plate, and its antifreezing effect is also more satisfactory.But because its water absorption rate higher (8%-10%), and to give first system " plate ", production technology is complicated, also difficult extensive use in actual engineering.

The objective of the invention is to: invent a kind ofly have good waterproof performance, good heat preservation performance, have certain elasticity and flexibility and material to be easy to get, price is low, technology is simple, be convenient to construct and insulation layer that can extensive use prevents the method for frost crack of irrigation ditch with rigid facing.

Main contents of the present invention: accompanying drawing is that channel drawing in side sectional elevation (1) is native canal bed, and (2) are insulation film pipe layer, and (3) are the levelling sand bed, and (4) are rigidity membrane layer, and (5) put insulation film pipe layer for canal.

The loose efficient heat insulating materials such as swelling perlite powder of filling (determined by the cross-sectional length of channel by the length of plastic flexible pipe in wall thickness is the plastic flexible pipe of 0.10-0.15mm; The diameter of plastic flexible pipe＜be insulation layer thickness by soil insulation, antifreeze calculating are determined), the two ends that is full of the plastic flexible pipe of efficient heat insulating material such as swelling perlite powder stays one section empty film pipe, it is dead with corrosion-resistant rope bundle that it is turned back, and accomplishes to make heat insulating material and isolate from outer air in the pipe.Just made insulation tunic pipe.

As shown in drawings, in the native canal bed of fixing (1),, promptly on native canal bed (1), constituted an insulation layer perpendicular to the closely parallel insulation tunic pipe (2) that makes that is paved with of the direction of channel.On insulation tunic pipe, re-lay the wet mixing layer of sand (3) of one deck 2-3cm, as the levelling transition zone.Go up cast-in-place or pave various rigidity membrane layers (4) at levelling transition zone (3).When laying insulation tunic pipe, should backguy on the two lateral slopes of Tu Qu, the backguy position should be higher than the waterline of design maximum flow.Insulation tunic pipe two ends and backguy snap, and are higher than the waterline of design maximum flow with assurance insulation layer pipe end point-blank.In adjacent film pipe two ends, the canal dike on both sides is down laid 2/3rds the insulation film pipe that width is a maximum depth of frozen ground along channel direction.Volt soil thereon again, its volt soil thickness should greater than with equal 30cm.To avoid the insulation film tube-surface to damage in the construction as far as possible.

The thick degree of plastic flexible pipe diameter＜promptly be incubated〉calculate by following formula:

H treasure=(H-(K snow h snow+k mixes h to be mixed+the husky h sand of k))/(k treasure)

In the formula: H-is the maximum frozen depth of local end insulation soil, can be checked in or be calculated with formula by local meteorological data.

$\mathrm{H=A(}\sqrt{P}\mathrm{+0.018P)}$

K snow, K mud, K sand, K treasure are respectively snow, coagulation surface layer, sand bed coefficient.Can be by finding in " K value table when different soil adopt different heat insulating material ".

H snow, h mix, h is husky-be respectively the thickness of local average snow depth, concrete surface layer thickness, levelling sand.

The anti-freeze expansion destruction methods that the insulation film pipe insulation layer of this filling crushed crude pearlite is used for the rigid facing channel has applicability preferably; Because the heat insulating material in the insulation tunic pipe is with flexible pipe and isolate from outer air, and its coefficient of thermal conductivity very low (0.04-0.05w/m.k), so it has good protection against the tide, waterproof, heat insulation function.Simultaneously because the insulation film pipe of filling crushed crude pearlite has certain elasticity and flexibility, even the moisture soil body like this under the insulation layer may because of some reason take place to a certain degree freeze and produce a certain amount of frost-heaving deformation also can absorb by insulation tunic pipe.And crushed crude pearlite and plastic flexible pipe material are easy to get, need not any reprocessing equipment, buy and to use construction technology simple, price is low, and to compare the result as follows with polystyrol plastic foam plate heat preserving method and hydrophobic pearlite board heat preserving method: the thickness with the method insulation layer when maximum depth of frozen ground is 1.5 meters as calculated is 12.5cm, and the insulation layer cost of materials that (being the plastic flexible pipe diameter) is every square metre is 9.35 yuan.If with polystyrene board insulation layer method, when maximum depth of frozen ground was 1.5 meters, its insulation layer funds calculated and should be 9.37cm, and then every square metre heat insulating material expense is 36.07 yuan, is 3.86 times of this method.If with the method for hydrophobic pearlite board insulation, when maximum depth of frozen ground was 1.5 meters, its insulation layer thickness was 23.58cm as calculated, then every square meter of material expense is 20.75 yuan, is 2.22 times of this method, so its applicability is conspicuous.

Example: the maximum frozen depth H that the somewhere is not incubated soil is 1.4 meters, and snow depth is the 10-30 centimetre, 15cm averages) the concrete pavement thickness h that will cast mixes and is 12cm, the husky transition zone of levelling is 3cm, and checking in COEFFICIENT K snow is 1.60, and K sand is 0.95, it is 1.14 that K mixes, and K treasure is 9.60.Then its plastic flexible pipe diameter H treasure (i.e. insulation mixes layer thickness) is

H treasure=(H-(K snow h snow+k mixes h to be mixed+the husky h sand of k))/(k treasure)

The above-mentioned every data of substitution:

Try to achieve h treasure=10.05(cm)

The thickness that promptly needs filling crushed crude pearlite plastic flexible pipe insulation layer is that 10.05cm(is that the diameter of plastic flexible pipe should be 10.05 centimeters).For safety, result of calculation be multiply by the global factor of safety of 1.2-1.4, the diameter of then getting plastic flexible pipe is that 12-14cm gets final product.

Claims (3)

1, a kind of method that is used to prevent frost crack of irrigation ditch with rigid facing.It is characterized in that by the insulation layer that efficient heat insulating material, plastic flexible pipe, sands etc. such as expanded pearlite powder are formed said insulation layer is with efficient heat insulating materials such as swelling perlite powders, is filled in the plastic flexible pipe, constitutes insulation tunic pipe.

2, according to the said method that prevents frost crack of irrigation ditch with rigid facing of claim (1).It is characterized in that said insulation tunic pipe is closely parallel being paved with on the native canal bed of fixing perpendicular to channel direction.

3, according to claim 1, the 2 said methods that prevent frost crack of irrigation ditch with rigid facing.It is characterized in that said insulation tunic pipe when laying, the two ends of film pipe should be higher than the waterline of the big design discharge of channel amount, and the two ends of film pipe will be pricked dead with the corrosion-resistant rope.

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