RU2225480C2 - Foundation for eccentric loaded column - Google Patents

Abstract

FIELD: industrial building and civil building foundations built on non-uniform soil settlement. SUBSTANCE: foundation has anchor bolts. Through nozzles are formed in foundation body. Nozzles are widened to foundation base and arranged symmetric to foundation axes x and y and in center thereof. Each nozzle is filled with particulate material, particularly with utilizable slag. Double-action pulsating jack is introduced in upper orifice of each nozzle. Jack support plate mating with upper nozzle orifice section is supported by particulate material. From below jacks rest by pistons against removable distribution bars. Ends of each distribution bar rest against removable ends of H-shaped frame. H- shaped frame center rests from below against jack bar connecting column arms. EFFECT: possibility of full design foundation position rebuilding after unbalanced immersion and tilt; decreased material consumption. 2 dwg

Description

The invention relates to the foundations of industrial and civil buildings during construction on soils with uneven settlement.

Uneven settlement is the main reason leading to the appearance of large stresses in the elements of the frame of the structure, to the appearance of cracks in the supporting structures and to the complete failure of the supporting structures, up to failure.

A well-known foundation for an eccentrically loaded column with anchor bolts for fastening [1, p. 368], taken as the closest analogue.

The disadvantages of the analogue are as follows:

- it is impossible to restore the design position of the foundation after uneven precipitation, since there are no devices in the foundation that can restore its design position;

- the material consumption of the foundation is excessively large.

The objective of the invention is the complete restoration of the design position of the foundation after its uneven settlement and roll and the reduction of material consumption.

The problem is solved due to the fact that in the body of the foundation under the eccentrically loaded column containing anchor bolts, according to the invention, through nozzles are made expanding to the bottom of the foundation, placed symmetrically with respect to the axes x and the foundation and its center, each of the nozzles is filled with loose a material, for example, slag requiring disposal, a double-acting pulsating jack is introduced into the upper hole of each nozzle, and the support plate of each jack corresponds to the profile of the upper hole with it is based on bulk material, the jacks are supported by pistons from below into removable distribution beams, the ends of each of the distribution beams are supported from below in a removable H-shaped frame at its ends, and the center 0 of this frame abuts against the bottom of the jack connecting the branches of the column.

The technical result provided by the invention consists in the complete restoration of the design position of the foundation after its uneven draft and heel and a decrease in material consumption.

Comparison of the developed foundation with the analogue shows its significant differences, namely:

- the foundation is equipped with through nozzles passing through the foundation body from top to bottom and expanding downward, and is a macroregulator that provides reduction of stresses in the building frame from uneven settlement of the foundation to a minimum;

- the foundation is equipped with a removable H-shaped frame connected to the column resting on the foundation and pulsating jacks placed between the H-shaped frame and bulk material placed in each of the nozzles;

- pulsating jacks interact with bulk material, for example, slag, in nozzles and squeeze out this bulk material in portions under the base of the foundation;

- each of the nozzles completely restores the design position of the foundation, and not only the sediment is eliminated, but also the foundation roll, both in the longitudinal and transverse directions, and therefore, stresses arising from uneven settlement of the frame are eliminated;

- by adjusting the volume of bulk material pressed into each of the nozzles with pulsation, the design position of the foundation is completely restored, not only the sediment is eliminated, but also the foundation roll, both in the longitudinal and transverse directions, and therefore, stresses arising from uneven settlement frame;

- the developed foundation allows you to stabilize the expected settlement during the construction process, and such stabilization can be performed several times as the mass of the structure increases;

- the mass of the foundation concrete is reduced, since the foundation has cavities in the form of nozzles.

Thus, the developed foundation is significantly different from the analogue.

In FIG. 1 shows a column connected by anchor bolts to a foundation.

In FIG. 2 shows a foundation in section.

The foundation 1 has nozzles 2 passing through the foundation and expanding to its sole. Nozzles 2 are placed in plan symmetrically with respect to the x and y axes. Each of the nozzles 2 is covered with bulk material, for example, slag, sand or gravel with the addition of a plasticizer to increase the flowability of the bulk material. Conventional clay may be used as a plasticizer. Along the long sides of the foundation 1, long beams 3 of the H-shaped frame 4 are installed. Long beams 3 are connected to each other by a beam 5 and form an H-shaped frame 4. The beam 5 is passed through a two-branch column 6 and rests against the jack beams 7 connecting the branches of the column from below 6. Column 6 is connected to the foundation 1 by anchor pins 8 having support straightening nuts from the bottom and fastening nuts from the top. The H-shaped frame 4 is connected to the anchor studs 8. Under the ends of the H-shaped frame 4 there are distribution beams 9 extending above the nozzles 2. Each distribution beam 9 is supported at its ends by a pulsating jack 10, which can be used as a hydraulic pulsator (5, p. . 368-369) (Fig. 2). In turn, the base plate of the jack corresponds to the profile of the upper opening of the nozzle 2 and rests on the bulk material in the nozzle 2. On the long beams 3, a short beam 5 of the H-shaped frame 4 is supported from above. The fifth pulsating jack 10 is installed in the center of the foundation above the center 0 of the fifth nozzle. The piston of this pulsating jack 10 abuts directly from below directly into the beam 5 of the H-shaped frame 4. The beam 5 of the frame 4 is laid between the branches of the column 6 and connected to the foundation 1 by anchor pins 8.

The stabilization and hardening of the soil base under the foundation during the construction process can be carried out in several stages.

Stage 1

The stabilization efficiency increases as the mass of the structure increases. The first stabilization is carried out after the construction of the foundations and is necessary for the implementation of accurate non-alignment mounting of the structure frame. The sequence of work is as follows:

1. Make a geodetic breakdown of the building and dig pits under the foundations.

2. In accordance with the geodetic breakdown, inflatable hollow formers having the profile and shape of nozzles in the foundation are mounted at design points.

3. Install the spatial reinforcing frame of the foundation and fix it relative to the hollow formers.

4. Install anchor rods according to the template and connect them to the reinforcing cage.

5. Install the outer formwork and fix it with respect to the reinforcing spatial frame.

6. The formwork is filled with concrete of the required grade, feeding it with a concrete pump according to the “bottom-up” principle, thereby eliminating the formation of voids. At the same time, concrete is compacted by deep vibrators.

7. After the concrete has set, air is let out from the void formers. Void formers are removed upwards and the formwork is dismantled.

8. Fill the cavity with bulk material, for example, slag, gravel, sand. To increase the fluidity of the soil, some kind of plasticizer is added, for example, clay, and the sinuses around the foundation are filled with any soil.

9. Install a pulsating jack of reciprocating action over each of the nozzles. When using a conventional jack, a higher power jack will be required.

10. Install the H-shaped frame, fix it to the anchor studs of the foundation, and the transverse beam 5 abuts from the bottom and connect to the jack beam of the branches of the column.

11. Turn on the pumping station, which drives the pulsating jacks, and compress the first portion of crushed stone with pulsation, thereby compacting and hardening the soil base under the foundation.

12. Turn on the reverse stroke of the pulsating jacks, pulling them to the H-shaped frame and freeing up space for a new portion of bulk material.

13. A new portion of bulk material is added to the vacated space and the cycles are repeated until the properties of the soil base under the base of the foundation stabilize and the foundation is squeezed out of the ground by the value of the settlement draft of the structure over time. The value of the oil pressure developed by the pumping station is recorded, and subsequently the same oil pressure is created on other foundations, thereby stabilizing the soil base by the same amount. It should be noted that the extrusion of the foundation from the soil is carried out exactly to the design level.

14. In the event of a roll of the foundation in the y-z plane (the z axis is oriented vertically), for example, the settlement of the right side of the foundation is greater than the left, then perform the following steps. The pulsating jacks 10 on the left side of the foundation rest directly on the foundation 1 and the cycles are repeated only with pulsating jacks located on the right side of the foundation until the roll is eliminated. Similarly, when a roll of the foundation occurs in the x-z plane.

15. In a similar manner, the properties of the soil base are stabilized under all the foundations of the structure, creating a calculated oil pressure controlled by a pressure gauge. The stabilization of the soil base is done by monitoring the actual position of the foundations, using laser or conventional levels.

Thus, the developed foundation fulfilled the functions of a macroregulator. After stabilization of the soil base, all foundations are returned to their design position, the properties of the soil base beneath them are leveled, the bearing capacity of the soil base is increased, and the value of precipitation predicted over time is significantly reduced.

2 stage

With a non-alignment method, the frame of the building is completely mounted and, after completion of construction, in buildings of increased reliability, for example, nuclear power plants, the soil base is re-stabilized. In this case, the stresses in the soil foundation under the basement of the foundation have already reached their normative value and have spread to a greater depth, and therefore, despite the fact that the initial stabilization of the soil has already been carried out, the building will be upset, although to a lesser extent.

To reduce rainfall several times use the new foundation as a macroregulator, re-stabilize the soil base in the manner described above (stage 1).

3 stage

The building is operated by regularly leveling the foundations, for example, once every six months of operation. In case of detection of precipitation of one or more foundations, individual stabilization of the soil base is carried out precisely at these settled foundations.

Simultaneously with the stabilization of the properties of the soil base, precipitation and heel are eliminated as described above.

Thus, the developed foundation is a macroregulator that allows you to build buildings on any soil and to regulate the stress state of the structure frame, achieving its optimal state.

The optimal state of the stress state of the frame will lead to a significant increase in reliability and reduce its material consumption.

The economic effect of the developed foundation arose due to the following:

- the use of the foundation as a macroregulator made it possible to exclude the harmful effect of uneven settlement of foundations on the supporting structures of the building frame and thereby significantly increase reliability and reduce the material consumption of the frame;

- simplified operation of the structure, since its design position is easily restored by means of a macroregulator, the functions of which are performed by a foundation with adjustable draft.

Sources of information

1. Belena E.I., Baldin V.A., Vedenikov G.S. and other metal structures. General course: Textbook for universities. - M.: Stroyizdat, 1986.- 478 p.

2. Metal structures. Edited by N.P. Melnikova. - 2nd edition, revised and supplemented - M .: Stroyizdat, 1980. - 776s. - (Designer reference).

3. Nezhdanov K.K., Nezhdanov A.K. The method of straightening the crane path. Russian patent No. 2104362, Bulletin No. 14, 1993.

4. Nezhdanov K.K. and others. The foundation for a metal column. The method of its construction and straightening. Patent of Russia No. 2123091, Bulletin No. 34, 1998.

Compiled by A.N. Inin

Claims (1)

A foundation for an eccentrically loaded column containing anchor bolts, characterized in that through nozzles are made in the body of the foundation, extending to the bottom of the foundation, placed symmetrically with respect to the axes x and the foundation and at its center, each of the nozzles is filled with bulk material, for example slag, requiring disposal, in the upper hole of each of the nozzles introduced a pulsating double-acting jack, and the base plate of each jack corresponds to the profile of the upper hole of the nozzle and rests on bulk material, the jacks are supported by pistons from below into removable distribution beams, the ends of each of the distribution beams are supported from below in a removable H-shaped frame at its ends, and the center 0 of this frame abuts against the bottom of the jack beam connecting the branches of the column.

Images