CN1068616A

CN1068616A - The anti-leakage method of pressure diversion tunnel man-made fracture control

Info

Publication number: CN1068616A
Application number: CN91104829A
Authority: CN
Inventors: 朱暾; 邢贵碧
Original assignee: WUHAN WATER CONSERVANCY AND ELECTRIC POWER COLLEGE
Current assignee: WUHAN WATER CONSERVANCY AND ELECTRIC POWER COLLEGE
Priority date: 1991-07-16
Filing date: 1991-07-16
Publication date: 1993-02-03
Anticipated expiration: 2006-07-16
Also published as: CN1027600C

Abstract

This method utilization steel concrete redistribution of internal force theory, employing is provided with several man-made fractures and hoop steel bar stress and is configured in two measures such as the lining cutting outside in the reinforced concrete lining layer precalculated position, the people is for causing the lining cutting redistribution of internal force, make that lining cutting becomes the large eccentric tension state by the small eccentricity tension state on the reinforced concrete, and in the inboard three dimension stress district that can not ftracture that forms of reinforced concrete lining layer, this three dimension stress district circularizes water-stopping system with embedding waterstop mutual group in advance, thereby satisfies the requirement of pressure diversion tunnel anti-leakage.This method combines application with prestressed reinforced concrete anti-leakage method, and effect is better.

Description

The anti-leakage method of pressure diversion tunnel man-made fracture control

The invention belongs to technical field of civil engineering, the anti-leakage method of particularly a kind of garden shape steel concrete pressure diversion tunnel.

The water-power plant pressure diversion tunnel has strict anti-leakage requirement, and traditional anti-leakage measure has following four types:

A) steel concrete is by the cracking computation anti-leakage;

B) adopt the prestressed reinforced concrete anti-leakage;

C) steel concrete lining steel plate anti-leakage;

D) the steel concrete inner surface is brushed with machine coating anti-leakage.

Above anti-leakage method can reduce two classes: a class (as A and B) is to manage to guarantee that reinforced concrete lining layer does not ftracture, thereby reaches the purpose of anti-leakage; Another kind of (as C and D) allows the steel concrete cracking and through crack occurs, controlling under the crack width prerequisite with steel plate or organic coating anti-leakage.Above method is anti-leakage effectively, but they or invest higher (as A and D), or construction complicated (as B), or maintenance difficulty (as C and D) exist some defective and deficiency.

The objective of the invention is to overcome the deficiency of conventional method, use simple manual presetting method for controlling crack and a kind of effectively anti-leakage of developing, can save construction investment again, shorten the pressure diversion tunnel anti-leakage method of construction period.

Concrete measure of the present invention is:

1) in steel concrete pressure tunnel precalculated position some man-made fractures is set, the position of man-made fracture preferentially is chosen in the less position of positive bending moment, but disposed at equal distance, also disposed at equal distance not, its penetration of fracture can be paid the utmost attention to and be 1/2 to 2/3 of reinforced concrete lining layer thickness, establish copper sheet or Rubber water stop band in the crack with effective sealing, man-made fracture should be able to effectively be born pressure and shearing, can pay the utmost attention to for this reason toothing is done in the crack, be provided with thick 3～5 millimeters between the crack, the steel plate of two oilings or pitch, steel plate is imbedded as dividing plate when concreting.

2) the hoop steel bar stress in the reinforced concrete lining layer is arranged in the lining cutting outside, its layout thickness can be considered in 1/2～1/3 lining thickness scope, divide one or more layers to arrange, its number of steel bars can be determined with the strength calculation formula that the water conservancy project Design Code of Reinforced Concrete provides according to the internal force size at man-made fracture place.

More than two measures to make the pressure tunnel reinforced concrete lining layer be that main load action issues the redistribution of internal force that the stranger is in internal water pressure, reinforced concrete lining layer section between any two man-made fractures is in large eccentric tension stress state, outside concrete in tension, form the normal crack district, its number of steel bars, crack width can be determined with water conservancy project Design Code of Reinforced Concrete given draw greatly partially component strength design formulas and the calculating of crack width calculation formula, and can make control of crack width in allowed band.

Analyze on the steel concrete large eccentric tension member section stress distribution also as can be known, the inboard concrete of reinforced concrete lining layer bears compressive stress, is in the three dimension stress state and can not ftractures.Reliable impervious drop ply and the antipriming between man-made fracture that this position concrete forms constitute an effective annular water-stopping system, thereby satisfy instructions for use.In order to prevent thermal cracking and shrinkage crack, the place is provided with the distributing bar net at pressure tunnel steel concrete inwall, guarantees the service behaviour of impervious drop ply, bears other loads simultaneously and forms the tensile stress that may produce at this position down.

Pressure diversion tunnel tradition anti-leakage method is it not to be ftractureed or the concrete that ftractures is crammed the purpose that the crack reaches anti-leakage by control reinforced concrete soil stress, shows as the anti-leakage of passive protection formula.The present invention reaches the anti-leakage purpose by the people for engineering measure changes stress state, shows as the initiatively anti-leakage of attack formula, thereby has opened up a kind of new anti-leakage approach.

The present invention also can combine application with the impervious method of prestressed reinforced concrete, be that the prestressed reinforced concrete anti-leakage is adopted in second garden, method anti-leakage of the present invention is adopted in first garden, build second garden concrete during concrete enforcement earlier, and second garden concrete applied prestressing force with post stretching, the location arrangements of prestressed reinforcement promptly is positioned at three branch places, cross section from the thick place of lining cutting inwall 1/3 lining cutting.Making lining cutting outside concrete answer pressure in advance is zero, thereby avoided country rock and concrete co-operation to applying prestressed influence, lining cutting is stressed clear and definite, it is obvious to apply prestressed effect, half garden stretching construction difficulty is little simultaneously, loss of prestress is less, has solved Quan Yuanzhou and has applied a prestressed technology difficult problem.After second garden construction finishes, build first garden concrete again, at this moment can the part of impervious drop ply is prefabricated, use as internal mold lifting splicing back, then can also further increase wage.

Adopt anti-leakage of the present invention, construction investment is suitable with the prestressed reinforced concrete anti-leakage, and job practices and programming are suitable with steel plate anti-leakage and coating anti-leakage again, and its economic benefit is conspicuous.Be not only applicable to hydropower station pressure tunnel anti-leakage, be applicable to the anti-leakage of other garden shape structure simultaneously yet.

Accompanying drawing one is a structure principle chart of the present invention.Wherein 1 is man-made fracture, and 2 is the hoop steel bar stress, and 3 is copper sheet or Rubber water stop band, and 4 is the normal crack district, and 5 is impervious drop ply, and 6 is prestressed concrete, and 7 is prestressed reinforcement, and 8 is the distributing bar net, and 9 is the steel concrete internal mold.

Claims

1, a kind of anti-leakage method of pressure diversion tunnel is characterized in that being provided with in steel concrete pressure tunnel precalculated position some the man-made fractures with copper sheet or Rubber water stop band; And with the hoop steel bar stress layered arrangement in the reinforced concrete lining layer in the lining cutting outside.

2, the anti-leakage method of pressure diversion tunnel as claimed in claim 1, it is characterized in that, the position of described man-made fracture can preferentially be chosen in the less position of positive bending moment, its penetration of fracture is 1/2 to 2/3 of a reinforced concrete lining layer thickness, the crack is a zigzag, and the thickness of imbedding as dividing plate when being provided with at concreting between the crack is the steel plate of 3～5 millimeters, two oilings or pitch.

3, as the anti-leakage method of claim 1,2 described pressure diversion tunnels, it is characterized in that: second garden prestressed concrete of building described pressure diversion tunnel earlier, and second garden concrete applied prestressing force with post stretching, the position of prestressed reinforcement can preferentially be arranged in from lining cutting inwall 1/3 lining thickness place.