SU939649A1 - Foundation - Google Patents

Description

The invention relates to construction and can be used in the construction of foundations in industrial and civil construction in seismic areas.

A foundation is known that is reinforced in the form of a reinforced concrete ring, they generally have a rigid connection with the shell in its upper part, the cavity of which is filled with sand, on which the reinforced concrete foundation plate is supported, having the possibility of free slip in the cavity of the shell (tl).

The disadvantages of this foundation are the increased labor intensity in compacting the soil around the foundation under a ring rigidly connected to the shell, reducing the reliability of the foundation in seismic areas and when working for stability.

The closest to the proposed technical essence is the foundation consisting of a reinforced concrete shell filled with sand, with a foundation shoe 12 supported on it,

The disadvantages of the known foundation - increased shell height, reducing the reliability of the foundation in seismic areas and when working on stability.

The purpose of the invention is to increase the reliability of the foundation for stability under the action of an off-center load in seismic areas and a reduction in material intensity.

The goal is achieved by the fact that the foundation / inclusive of a shell filled with a bulk material and mounted on a bulk material

10 bgiomak, the contour of which repeats the contour of the shell, is sybzhen with a short pile vertically placed in the bulk material, the lower surface of the support baimuck is made convex and curved with a central recess into which the upper end of the short pile is wound.

At the same time, the transverse dimensions of the support arm in the plan are 0.63–0.85 of the corresponding dimensions of the shell, and the height of the curvilinear part of the support batsmak is 0.1–0.25 smaller than its transverse length.

25 size.

The drawing shows the proposed foundation.

The foundation contains a shell 1 in the form of a square, rectangle,

30 circle and other shapes. Inside

3a7-lien shell of loose material cm 2, on which the foundation shoe 3 with the corresponding shell configuration is supported. In the central part of the shoe sole, there is a recess in which the upper part of the short pile 4 penetrates the bulk material to a depth not exceeding the lower edge of the shell. The tip of the piles fell out in the form of a wedge (if the shell is rectangular), a rhombus (if the shell is in the form of a square), a cone (if the shell is in the form of a circle), etc.

The reinforced concrete shell is manufactured by known methods, and the reinforcement is accepted by calculation. Bulk material is poured into the casing. A template is formed with a mock that displays the shape of a shoe segment, in the central part of which there is an opening for a short reinforced concrete pile. The template is removed and in its place a prefabricated foundation shoe is installed with a recess in the base of the segment for the piles.

The bottom of the shoe has the shape of a segment, which is characterized by the height of the perpendicular of the DS, restored from the middle of the chord AB to the Intersection with the arc AB. The length of the chord AB is equal to the diameter of the sole (if the shoe has the shape of a circle) or the lengths of the square (if the shoe has the shape of a square or rectangle). - 0.25 AB, where Ned is recommended optimal

height perpendicular to diabetes, m

In the central part of the segment there was a recess with the dimensions of ZOOHZOOx XU and 400x400x200 mm, etc. The lateral dimensions of a reinforced concrete pile are taken from the calculation of the effect of transverse force or flexural moment in the calculation of stability.

Depending on the type of backfill material, the length of the pile is assumed to be large (if the backfill material is sand) or less (if Lean concrete). A gap of up to 10 mm is allowed between the walls of the recess and the walls of the pile.

Short reinforced concrete improves the work of the entire foundation for horizontal loads, including seismic, makes the foundation stable against tipping, and also improves the joint work of the backfill material and the reinforced concrete shell.

If the formwork and shoe is circular

F.6 o6t GD8 yf | 5 diameter base foundation MccCff Mi /

dnR - inner diameter of the shell m.

; If the formwork and the shoe have the shape of a square or square AF.5 kc.A | tf, B.5 kc-B ||,.

where AF0, VO.R - the side of the foundation and n ° shoe, m; o6 cS side shell without

taking into account its thickness; kc - coefficient obtained experimentally by way, ke 0,63-0,85.

The height of the segment depends on the type of backfill material and the size ratio of the shell and the shoe.

The operation of this design is as follows.

The load through the foundation shoe is transferred to the backfill material. In the absence of a shell in the backfill, shear stresses along the border of the sole of the shoe — rgyHT backfill — develop, which limits the limit of external loads. The presence of the shell eliminates this drawback and the magnitude of the external load on these biomacs increases by 2-2.5 times. The backfill material, compacted by means of friction force and lateral pressure forces, is drawn into the draft and the shell. As a result, the ground pressure under the bottom edge of the casing does not exceed the calculated one. . But such a sole construction is very unstable and does not work well when checking for tilting. To eliminate this drawback, a short pile is suggested.

The proposed Foundation is designed for use in the construction of frame industrial and civilian single and multi-storey buildings and structures with central and eccentric load application in seismic regions of theirs, at loads of 100-60D tf in all soil conditions, both without prior improvement and with production complex work to improve them.

Material savings are achieved by reducing the height of the shell and the volume of backfill, increasing the reliability of the foundations in seismic areas, which eliminates the need for additional work to ensure the seismic stability of buildings in cel.

Claims (2)

1. The foundation, which includes a shell filled with bulk material and a baipfak installed on bulk material, the contour of which repeats the shell contour, characterized in that, in order to increase the foundation's reliability for stability under off-center load in seismic areas and reduce material intensity, it is equipped with a short pile vertically placed in C1 1 the bulk material, and the bottom surface of the support shoe is made convex and curvilinear with a central recess into which the upper th short piles. 2. The foundation of claim 1, about tl and ch.ay and i, with the fact that the transverse dimensions of the support shoe in the plan are 0.63-0.85 of the corresponding dimensions of the shell, and the height of the curved linear part of the support The shoe has a 0.1-0.25 size smaller than its transverse size. Information sources, taken into account during the examination 1. Savinov O.A. Modern capital constructions. L.-, Stroiedat, 1964, p.225. 2. Investigation of foundations, foundations and hydraulic structures. Volume 216.- Proceedings of the NPI, Novocherkassk, 1970, p. 158 (prototype).