SU1252507A1 - Drainage of lining - Google Patents

Description

The invention relates to devices for drainage of underground workings and can be used in the construction of tunnels and other underground structures.

The purpose of the invention is to increase the durability of the lining by reducing the unevenness of its deformation.

FIG. 1 shows a diagram of the proposed drainage device; in fig. 2 - diagram of the deformation of the tunnel lining under the action of external loads; in fig. 3 - the same from the side of the drainage device.

The drainage device (Fig. I) is made in the form of cavity 1 behind the lining 2 with drainage 3. It is provided with elastic support rods 4, radially mounted in the zone 5 of the elastic compression of the soil. The rods are rigidly fixed in lining 2 and in the ground 6 with the same pitch. The number of rods is determined by the ratio

e

p kFn

EF where k is the coefficient of elastic pressure of the rock, kN / cm;

FO is the area of the outer surface of the lining in the zone of elastic compression on the side of the drainage device, cm 2;

t is the length of the free part of the rod (without taking into account the length of the fixed ends), cm;

F. — elastic modulus of the rod material, kN / cm;

F - rod cross-section area, see

The dimensions of the zone 5 of elastic compression and the length of the embedment of the ends of the support rods 4 are determined from the conditions of compatibility of deformations of the lining and the soil, as well as providing the necessary strength and rigidity of fastening the rods.

The device works as follows.

The tunnel lining 2 is deformed under the action of vertical loads.

positioning the zone 5 of the elastic compression of the soil in the region of the walls, while the lining mixes are directed radially. At the same time, the lining is deformed at the location of the drainage device. Its radial mixing is prevented by elastic support rods 4, in which forces arise, causing compression deformations of the rods. Since the elastic rods are oriented radially, are located with the same pitch and rigidly fixed ends, and their number is determined by the relation (1). radial displacements of lining U; from the side of the drainage device and adjacent areas are the same.

From the condition (1) it follows that

k f EF, or -,

 K-iEF

le

where PLJ-P is the resultant of the reactive stresses at the contact of the compressed soil with the lining section

Y area enclosed in

i-th point (Fig. 2a);

PI. St - reactive force in the support rod of the 4th drainage device, fixed respectively at the i-th point (Fig. 26).

Since the indicated expression is an equality, then P {, c

; k

Member P; k in the left part of the above expression represents the displacement at the contact of the lining with the ground, the member Pier: FF of the right part is the shortening of the support bar and,;. at the corresponding point of the drainage device.

If it is necessary to anchor the arch of the lining in the drainage device, outside the zone of elastic compression, support rods can also be installed, the number and dimensions of which are determined according to the strength conditions of embedding the ends and the perception of tensile forces.

FIG. 2

/

-t

Fig 3

Claims (1)

FAMILY TRANSFER rigidly fixed at one end to the lining. and for others, in the rock, while the number of rods is determined by the ratio η = KF ₀ / p, where K is the coefficient of elastic resistance of the rock, kN / cm ³ ; E _about the outer surface area of the lining in the zone of elastic compression of the rock from the drainage device, cm ² ; f the length of the free part of the rod (excluding the length of the fixed ends). cm; E modulus of elasticity of the material of the rod, kN./cm ² ; 1 'is the cross-sectional area of the rod, cm ² . SU 1252 Fig 1