SU1701789A1 - Method for construction of sectional slope lining - Google Patents

Abstract

FIELD OF THE INVENTION The invention relates to hydraulic engineering and land reclamation construction. The purpose of the invention is to reduce seepage losses and simplify the production of works by intra-volume self-shrinking of the screen as a result of soaking during the launch of water through the canal. A layer of 0.015–0.03 m of swelling material 2, for example, bentonite clay, with a swelling pressure determined by dependencies is laid on the soil base 1 over the entire insulated surface and water is planned with a swelling pressure determined by dependencies. Elastic waterproof walls are laid along the axis of the interplate gaps. strip gaskets 3 and assemble the plates 4. In the interplate gaps, an anchor 6 is arranged, the armature of which is connected to the reinforcement laid in the joint cavity, and monolithic them together. 3 з.п f-ly, 2 ill.

Description

The invention relates to hydraulic engineering and land reclamation construction, in particular, to the construction of prefabricated linings with anchor fastening and an anti-filtration screen, erected on soil slopes of canals and reservoirs.

The purpose of the invention is to reduce seepage losses and simplify the production of work by intravolume self-compression of the screen as a result of soaking during the launch of water through the canal.

Figure 1 shows a fragment of the lining of one reinforced concrete slab; Fig. 2 is a plot of relative swelling of bentonite or its mixture with sand versus relative stress of the load.

The method is carried out as follows.

A layer of 0.025 m of swelling material 2, for example, bentonite clay with a swelling pressure of 0.0012 MPa or 10% (by weight) of clay powder with pressure, is laid on the soil base 1 over the entire insulated surface of the slope as an anti-filtration screen. 0.3 MPa swelling uniformly mixed with 95% sand, while the swelling pressure of the mixture is 0.0012 MPa. The force holding the slab on the slope, taking into account the mass of the slab and the resistance of the pull-out anchors, is 0.0012 at each point.

slabs

0.8

, 0015 MPa.

X |

The pressure of the swelling of the material is selected according to

77 (Ub h 1h

m

 +

-d-ln b-a

c), 0)

where K is the safety factor (1.3-1.1);

уь - volume weight of concrete suspended slab,;

h is the plate thickness, m;

m is the slope coefficient;

,14;

l, d - length and diameter of anchors, m;

p - the number of anchors, pcs;

B, a — width and length of the slab, m;

c is the specific cohesion of the soil of the base, MPa, and the thickness of the layer is selected according to

A ICB, / m

.- - hnp, (2)

AiIH.O

where ABcb is the amount of free swelling of a material sample with an initial height equal to the sum of the layer thickness and the Penetration depth hnp it into the pores of the base soil, m;

Ain.o - the relative value of the swelling is equal to the ratio of the height of the swollen Sample to its original height without load, minus one, the proportion of units;

hnp is the depth of penetration of the material as it swells into the pores of the base of the cladding, m,

. SnabT0-Sh

ppr20

where the snab pressure is swelling according to (1), MPa,

r0 is the reduced radius of the filter pores of the base of the lining, m,

P- porosity of the base soil, fractions

unit;

k is the coefficient of filling of pores during the penetration of the material, the fraction of units;

0 - resistance to shear of the swollen material, MPa,

moreover, the minimum allowable thickness of the layer of swelling material is determined by

5ztsch 2 D Tosn + 2 D 1pl. (3)

where A bsn is an indicator of the accuracy of the layout of the base of the lining, m;

A tnfl is a measure of maintaining the thickness of the cladding plate, m. Then, along the axis of the interplate gaps, elastic waterproof tape pads 3 are placed on the screen in accordance with the layout map of the plates and then the plates A are assembled in the interplate gaps, reinforced grooves and cavity junction 7 and monolith them together Produced concreting the bottom of the channel and shoulders 8. After completion of construction and start-up

water through the channel as a result of soaking occurs intravolume self-compression of the layer of the screen. In this case, the volumetric swelling is compensated by the force holding

the slab on the slope is in accordance with the generalized dependence of the relative swelling on the relative stress of the load (QM. Figure 2). In the graph, the unit of swelling of bentonite or its mixture with sand takes the swelling when the layer is saturated with water in a free state (without a load) and the stress that completely balances the swelling pressure. The equilibrium condition without lifting the slab is observed at point A. The selection of the compositions of stress cement and sand mixtures is carried out experimentally in single-use water meters.

Claims (4)

1. The method of construction of the team slope facing, including the construction of a pro-screening screen, laying along the interplate clearances elastic waterproof gaskets, installation of precast reinforced concrete slabs, their attachment to the slope by anchors embedded in the interplate cavities, mono-molded with anchors, different so that, in order to reduce filtration losses and simplify the production of works by intra-bulk screen self-shrinkage as a result of soaking when water flows through the canal, as a screening screen over the entire insulated surface, before installing the plates, lay a 0.015 thick layer of swelling material .. 0.03 m with the provision of the swelling force acting on a unit of area at any point of the slab within 80 ... 90% of the force at this point holding the slab on the slope. 2 The method according to claim 1, about tl and h a y i and with By using bentonite clay powder with a swelling pressure of 0.0012 ... 0.3 MPa as a swelling material. 3. The method according to claim 2, characterized in that when using bentonite clay with a swelling pressure of 0.004 to 0.3 MPa, 5-95% of sand are added evenly into the sand, respectively. 4. A method according to claim 1, characterized in that on canals and ponds with year-round filling, a mixture of tensile cement and sand in the ratio 1: 4-1: 2 is used as a swelling material, W Ъ4 0,6 0,6 1,0 Aspirated strain voltage  Phys.