US2382768A - Means for lowering a construction with a comparatively large base into the soil - Google Patents

Description

s. H. H. ZWEERG 2,382,768 MEANS FOR LOWERING A CONSTRUCTION WITH A COMPARATIVELY LARGE BASE INTO THE SOIL Filed July' 31, 1840 2 $heetsSheet 1 5 6 d 5 OlT A 4 o\ A M n W INVENTOR 5.16419. Zmesns ATTORNEY.

Patented Aug. 14, 1945 MEANS FOR LOWERING A'CONSTBUCTION WITH A COMPARATIVELY LARGE BASE INTO THE SOIL Bernardus Hermanus Henricns Zweers, Naarden,

Netherlands todian vested in the Alien Property Cus- Application July 31, 1940, Serial No. 343,940

In Germany August 8, 1939 12 Claims.

The invention relates to the lowering into soil up to the required depth of foundational constructions which have been previously constructed in their entirety or in part-as for example the section of a tunnel, a quay foundation, or any foundational construction in general with a comparatively large basic surface-by means of washing away the supporting soil. The lowering of piles and sheet pilings according to the jetting method whereby by means of a spurting jet the resistance of the soil is .so diminished that the pile or sheet can be introduced into the soil through its own weight or by loading, for example with the help of a drop hammer-is well known and in general use.

The invention, however, relates to the lowering of a foundational construction with .a comparatively large basic surface into the soil up to the required depth, and is particularly effective when an even distribution of pressure over the underlying soil is of major importance.

The soil may be excavated, for example to' within one meter of the required depth and .is as far as possible flattened. Then the roundational construction is placed and lowered into position, or is wholly or partly constructed .on the spot. Thereafter a liquid is led under the construction in supply pipes that have been previously provided. If this properly done, the sand will be Washed away allowing the construction to sink.

Such a method, however, requires special precisions, since irregularities in the previously flattened soil cannot always be avoided, especially when the flattening has to he done under water, and moreover since soil is not, as a rule, homogeneous, unequally distributed pressure is usually inevitable, causing very :great extra strain to the afloundation, as tor instance in the case of a very long tunnel section. Besides, if the liquid were then "to be supplied, there would be the difilculty that the Water would "-flow along quite irregular paths of the least resistancewhich cannot be ascertained beforehand, so that the soil would not be washed away evenly over the whole surface. Consequently, the right position and an-even pressure for the construction on the soil would not be obtained.

Therefore, acording to the invention .r'ibs, preferably with a triangular cross section, are fixed to the base of the construction. When .aioundational construction provided with such .ribs is lowered :on to soil that has been previously flattened or dredged, .these ribs penetrate the soil ribs and the surface of the soil. .If liquid is now,

led under the foundation it will find an outlet in these ohannels. When the velocity of the liquid is sufficiently hi h. soil will be carried away by it. Such displacement of the topmost later I of soil between the penetrating ribs causes .an increase in the pressure per surface unit of soil: equilibrium is consequently disturbed, and the construction sinks until'a new equilibrium has been'obtaincd. This process generally takes place continuously, and is carried on until the required depth has been reached. f

Since, theribs, and consequently also the channe'ls'l'imitedby them are regularlydistributed over the whole of the base of the construction, and since .the liquid generally flows through all the channels fltaneoulslv, uniform penetration and almost the same .5011 pressure iS obtained all over.

Moreover, toensure that ressure is evenly distributed along the Whole length of .a rib, the .removal of soil from the channel itself can be effected ularly. The iurther one gets from the beginning of the channel, the greater will be the velocity .of the liquid required .to transport the soil. This determines the widthof the cham nels which can be ascertained by experiment. The necessary decrease in their widths may :be

o'bta'inedby filling them .upat the top, increasing channel.

vByfldividi ng the number of ribs :into :atdeast 3 groups to which =theliquid :can be supplied in- To avoid subsequent sinking caused by fur-' ther penetration of the ribsowing to'g-reat loads,

the pressure on the soil during or immecliately after thepenetration of the ribs may be increased beyond the maximum that the buildmg is expected to weigh on completion. In addition I the channels as well as the spaces adjoining the sides of the foundation may be filled up, for instance with concrete.

The liquid can be led from an axial rib to both sides by means of channels. But this can also be done from one, or from two opposite sides of the foundational construction, whereby in the first case all channels e'ndon one side, and in the second case alternatively on opposite sides.

If an axialrib is applied, by making the ribs on the one side opposite the channels on the other side of said 'axialrib (Figs. 6 and 7),and by arranging that most of the liquid for the one channel is supplied from the opposite rib on the other side of the axial rib, the width of this axial ribmay be decreased. r

The invention also includes within its scope constructions which can be sunk into the soil according to this method. and furthermore j'a separate supporting plate (Figs; 6 and '7) provided with ribs which may be substituted for the specially made lower portion of the construction, and on which thereforethe construction can be placed. i

, In the accompanying drawings these embodiments of the invention are illustrated, embodying the principal features of this invention. v

Fig. 1 shows a cross section of a concrete block with two adjoining tunneltraflicroads;

Fig. 2 shows part of the vertical section along the line IIII f Fig. 1;

Fig. 3 is a horizontal sectional detail view taken alongthe line III-III of Fig. 1;" i

Fig. 4 is a'bottom'plan view of Fig. 1;

Fig. 5 is' a sectional view through'a slightly modified form cf'the'inventionf Fig. 6 is a sectional view through another modified form of the invention;

Fig. 7 is a bottom plan view of Fig. 6. Y

At the bottom of the tunnel in the drawings there is a lengthwise axial rib 2 of which they cross section is a'triangle with its base uppermost, and from which axial ribs 3 with'the same triangular cross sectionextend transversely to both sides of the tunnel, forming channels .4 between them.

By employing a filling in the upper portion of each channel 4 (Figs. 2 and 4), thecross sectional areas of the channels aredimini shed from the center toward the outerends. Experiments have shown that thereby the soil 6, which owing to the Weight of the construction. I, partly presses into channels 4. The channels are thusformed into tubular passageways, so that the soil will be evenly carried away when liquid flows through the passageways. v

From the axial rib 2 by means of a partition 8 and stream directors 9 the liquid supplied to channels I4, [5, l6 and I], by tubes], is caused to flow outwards to both sidesthrough the chanthe supporting plate.

When the superstructure and specially constructed lower portion form a unitary structure 'as shown in Fig. 1, the tubes may be arranged in-the middle as indicated by I, but when a separate supporting plate is provided it is preferable toconnect'thepipes I at the sides as shown in Fig. 5. i

According to Figs. 3 and 4 there is a cross partition i3 dividing the channels into four groups 14, 15, i6 and H. For example, if the rear or the right side of the construction should sink too far, less or no liquid at all is supplied to the groups I 4| 5 and |5|6 respectively.

In Figs. 6 and 7 another'modification is shown wherein the superstructure la is mounted upon a separate plate Ilc having'a centrally disposed rib 20 and a plurality'of transversely disposed ribs 2| extending outwardly from the center rib thereby forming channels 22 therebetween, which channels are similar to channels 4 previously described. The ribs 2| on one side of centrally disposed rib 20 are placed opposite the channels 22 on the other side of rib 20, and the liquid for each channel 22 is supplied from a conduit 23 in a rib 2| on the opposite side of the central rib 20.

Having now particularly described and ascertained the nature of said invention and the manner in which it can be performed, I declare that what I claim is:

1. In combination, a tunnel section, foundational construction-supporting plate or other threedimensional construction with a large basic sur- .face, a plurality of substantially parallel spaced ribs formed on the underside and extending to the edge of said surface thereby 'forming intermediate spaced channels between said ribs of substantial depth at said edge, said ribs adapted to cooperate with the earth to form tubular passageways extending to the edge of said basic surface, and means for directing liquid longitudinally through said passageways in order to wash laterally away the earth from under said construction.

2. In combination, a tunnel section, foundational construction supporting plate or other threedimensional construction with'a large basic surface, a plurality of substantially flush-top spaced ribs formed on the underside and extending to the edge of said surface, thus providing spaced chan nels between the ribs of substantial depth at said edge, said ribs adapted to cooperate with the earth toform tubular passageways extending to the edge of said basic surface, an axial rib disposed transversely of said first ribs and forming a cross-sectional closure for each of said intermediate channels, and means provided at the closed end of each channel for directing liquid longitudinally through said passageways in order to wash laterally away the earth-from under said construction.

3. In combination a tunnel section, foundational construction supporting plate or other construction'having a large basic surface, and having a vertically disposed sidewall, merging with said surface edge, a plurality of substantially flush-top spaced ribs formed on the underside of said sur face and extending to said edge, thus providing spaced channels between the ribs of substantial depth at said edge, said ribs adapted to cooperate with the earth to form tubular passageways extending to the edge of said basic surface, and means for directing liquid longitudinally through said passageways in order to wash laterally away the soil from under said construction, the cross sectional areas of the channels decreasing in the direction of the flow of the liquid.

4. In combination, a tunnel section, foundational construction supporting plate or other three-dimensional construction with a large basic surface, a plurality of substantially flush-top spaced ribsformed on the underside and extending to the edge of said surface, thus providing spaced channels between the ribs of substantial depth at said edge, said ribs adapted to cooperate with the earth to form tubular passageways extending to the edge of said basic surface, an axial rib disposed transversely of said first ribs and forming a cross-sectional closure for each of said intermediate channels, and means provided at the closed end of each channel for directing liquid longitudinally through said passageways in order to wash laterally away the earth from under said construction, the cross-sectional areas of the channels decreasing in the direction of the flow of the liquid.

5. In combination with a construction having a large basic surface, a plurality of substantially flush top spaced ribs formed upon said surface thereby forming intermediate channels of substantial depth throughout the entire length of the latter, said ribs adapted to cooperate with the earth surface to form each of said channels into a tubular passageway extending to the edge of said surface, said channels being open on their undersides and decreasing in cross-sectional areas toward said edge, and a plurality of means for directing liquid longitudinally through each of said passageways in the direction of decreasing cross-sectional area to Wash laterally away the earth from under said construction.

6. In combination with a construction havin a large basic surface with sidewalls extending upversely of said first ribs and forming a. crosssectional closure for each of said channels, and means for directing liquid through said passageways to wash laterally away the earth from under said construction.

8. In combination with a construction having a large basic surface with sidewalls extending upwardly from the edges of said surface, a plurality of spaced ribs formed upon said basic surface thereby providing intermediate channels,

each channel having an orifice of a substantial cross-sectional area at the intersection of said basic surface with at least one of said sidewalls, said ribs adapted to cooperate with the earth surface to form each of said channels into a tubular passageway, said channels decreasing in cross-sectional areas toward the respective orifices, and means for directing liquid through said passageways to wash laterally away the earth from under said construction.

9. In combination with a construction having a large basic surface with sidewalls extending upwardly from the edges of said surface, a plurality of spaced ribs formed upon said basic surface thereby providing intermediate channels, each channel having an orifice of a substantial cross-sectional area at the intersection of said basic surface with at least one of said sidewalls, said ribs adapted to cooperate with the earth surface to form each of said channels into a tubular passageway, a second rib disposed transversely of said first ribs and forming a crosssectional closure for each of said channels, said channels decreasing in cross-sectional areas toward the respective orifices, and means for directing liquid through said passageways to wash latwardly from the edges of said surface, a plurality of spaced ribs formed upon said basic surface thereby providing intermediate channels, each channel having an orifice of a substantial cross-- sectional area at the intersection of said basic surface with at least one of said sidewalls, said ribs adapted to cooperate with the earth surface to form each of said channels into a tubular passageway, and means for directing liquid through said passageways to wash laterally away the earth from under said construction.

7. In combination with a construction having a, large basic surface with sidewalls extending upwardly from the edgesof said surface, a plurality of spaced ribs formed upon said basic surface thereby providing intermediate channels, each channel having an orifice of a substantial cross-sectional area at the intersection of said basic surface with at least one of said sidewalls, said ribs adapted to cooperate with the earth surface to form each of said channels into a tubular passageway, a second rib disposed transerally away the earth from under said construction.

10. In combination with a construction having a large basic surface and having a sidewall extending upwardly from the edge of said surface, a rib formed upon said surface, two groups of transverse spaced ribs on said surface and extending respectively from each side of said first rib to said edge, thereby forming intermediate channls between adjacent transverse ribs, each channel having a substantial cross-sectional area at the intersection of said basic surface with the sidewall, said transverse ribs adapted to cooperate with the earth surface to form each of said channels into a tubular passageway extending to said edge, liquid supplying means arranged in each transverse rib on one side of the first named rib and opening into a channel between adjacent transverse ribs on the other side of the firstnamed rib.

11. A construction as set forth in claim 10- wherein the transverse ribs on one side of the

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