US3438207A - Method of making concrete retaining wall in earth situs - Google Patents

Description

April 15, 1969 L, A, TURZILLQ 3,438,207

METHOD OF MAKING CONCRETE RETAINING WALL IN EARTH SITUS Filed Deo. 2o, 1967 sheet df 2 /83 II BY Ll v.

Attorney April 15, 1969 L.. A. TuRzlLLo 3,438,207

METHOD OF MAKING CONCRETE RETAINING WALL IN EARTH SITUS Filed Dec. 2o, 1967 i sheet 2 of 2 1 J la (g5 K 13B 21./ INVENTOR. 2f 8 4Z Le@ Amadio MMM www Attorn eg United States Patent O 3,438,207 METHOD OF MAKING CONCRETE RETAINING WALL IN EARTH SITUS Lee A. Turzillo, Bath, Ohio (2078 Glengary Road, Akron, Ohio 44313) Filed Dec. 20, 1967, Ser. No. 692,072 Int. Cl. E02d 29/16, 29/00 U.S. Cl. 61-35 6 Claims ABSTRACT F THE DISCLOSURE BACKGROUND OF INVENTION In the past, the general method used to protect a building against collapse, while excavation work was being done closely adjacent the building, for example, has been to drive or form sheet piling, or cast-in-place concrete piles, close to the building foundation. This procedure was time-consuming and expensive. Sheet piling means sometimes used to retain earth surrounding an excavation was not always suitable because it placed serious limitations on how close to a building foundation the excavation could be made.

SUMMARY OF INVENTION The method of the present invention, as an example, may be used for making a concrete-retaining wall or bulkhead directly against or substantially close to building foundations without causing or permitting collapse of the building. In a typical use of the method, porous-walled bag means are, in a downward progression of successive layers thereof, inflated to expand and harden in fixed relation to relatively fixed structural surfaces within the situs to be supported thereby. The spaces for each downwardly successive layer of bag means are provided by progressive, removal of earth below successively fixedly supported and hardened bag means, in coordination with progressive layer-by-layer removal of earth from the excavation cutoff area.

A general object of the inveniton is to provide an improved method of the character described which makes it possible to provide a protective cast-in-place concrete wall, tightly in an earth situs and close to a building foundation, without endangering the building at any time during or after formaton of the protective wall.

These and other objects of the invention will be manifest from the following brief description and the accompanying drawings.

Of the accompanying drawings:

FIGURES 1 to 4 are fragmentary vertical cross-sections through an earth situs, adjacent a building or like foundation therein, and generally illustrating a progressive series of steps of the method of the invention, an additional step, corresponding to that of FIGURE 3, being shown in chain-dotted lines in FIGURE 4.

FIGURE 5 is a cross-section corresponding to FIG- URE 3, but illustrating how an excavation cut-off Wall is completed by repetition of the steps of FIGURES 2 to 4, in conjunction with step-by-step, downwardly progressive 3,438,207 Patented Apr. 15, 1969 Fice removal of earth to form an excavation of given depth.

FIGURE 6 is a fragmentary top plan view illustrating a portion of the finished cast-in-place concrete wall shown in FIGURE 5.

FIGURE 7 is a view corresponding to FIGURE 6, but broken away and in cross-section to show modifications, including cross-bar inserted between H-bar flanges to restrain expansion of bag wall.

FIGURE 8 is a fragmentary vertical cross-section taken substantially on the line 8-8 of FIGURE 7.

Referring particularly to FIGURES 5 and 6, there is illustrated a cast-in-place concrete wall 10, produced by the method of the invention, to prevent cave-in of earth E of a situs, close to a building foundation or like structure F, while workmen are digging or scooping out an excavation 11 (see FIGURE 5), as for another building (not shown). Wall 10, composed of concrete-filled bags or bag means 14a, 14a superposed one upon another may be constructed by the cast-in-place method of the invention, without use of heavy, bulky equipment previously required for forming sheet pile walls for protecting excavation cut-off areas. The method also avoids damaging earth cave-ins which could occur when any kind of wall or sheeting is built next to a building, especially after the excavation is dug to full depth.

Various objections to prior art methods for forming protective walls around excavation cut-off areas, next to a building or like foundation in an earth situs, for example, are obviated by the method of the present invention, exemplified in the following description thereof.

First, a series of elongated, rigid elements, in the form of steel, H- shaped soldier beams 13, 13 are, by suitable means, driven vertically into the earth of the situs E to be transversely spaced with reference to each other around the predetermined periphery of the excavation cut-off area. FIGURE l shows one such soldier beam 13 driven or otherwise provided in the earth, near a building foundation F, and to a depth extending beyond the estimated depth of the required excavation.

Next, the earth may be scooped out to a predetermined small proportional extent 11a of the full required depth c-f excavation 11, and to an excavation cut-off line 16, outwardly of the soldier beams 13, as shown in FIGURE 2, and then a closed flexible-walled bag or bag means 14 is placed in the cavity portion thereby dened between two transversely adjacent soldier beams 13.

Hydraulic cement mortar, supplied under pressure from a power-operated pump (not shown), is now injected into the first bag means 14, through a conduit 15 (see FIG- URE 2), until the fabric walls of the bag are expanded to shape substantially as shown in FIGURE 3. The bag Walls are thereby yieldingly distended into conformity with the shapes of contacted wall portions, within channels 17, =17 of the next adjacent soldier beams 13 (see FIGURES 3 and 4), as well as being expanded into tight conformity with earth cut-off walls 16 created by the aforementioned partial excavation 11a. Upon hardening of the cement mortar in the expanded bag means 14a, the walls thereof are thereby bonded in tight frictional engagement with the contacted surfaces of the soldier beams and the earth surfaces 16 and 18.

Upon setting or hardening of the cement mortar in the first layers of bag means 14, between successively spaced soldier beams 13 all around the excavation area, generally as shown in FIGUR-E 3, additional earth is removed from the excavation area, as illustrated at 11b in FIGURE 4, to provide a cavity 19 beneath the first expanded bag means 14a of each section between adjacent soldier beams. A second bag means 14 is then positioned in each cavity 19, as shown in full lines in FIGURE l4. The second bag means 14 is then expanded by injection of mortar, as before, to the condition shown in chain-dotted lines in FIG- UR-E 4. Upon hardening of the concrete mortar in the second bag means 14, as described above, the grout-expanded flexible walls thereof are iixedly supported by being bonded to the first expanded bag means 14a, to earth surfaces 16a and 18a and to the soldier beams 13.

These bag positioning and partial excavating steps are repeated, as described above, until full depth of the excavation is achieved as shown at 11 in FIGURE 5, and until the resultant concrete wall is extended as necessary in columns 21, 21 of superposed expanded bag means 14a, around the excavation cut-off area (see FIGURE 6).

Pressure-induced bonding of the bag walls to each other, and to surrounding structures, including the soldier beams 13, and earth structures, is substantially increased by use of bag means 14 made of porous fabric, such as square-mesh burlap or other porous sheet materials. In use of such porous fabric, a small fraction of iiuid, pressurized mortar injected into each bag means is extruded through such porous bag walls to form a thin coating of self-hardenable concrete, which conforms and becomes bonded to irregularities in the concreted surfaces. The extended mortar from next adjacent bag walls unites as substantially integral connecting layers of concrete.

Elongated rods may be suitably incorporated lengthwise within the respective bag means 14, prior to the groutinjection step. Each expanded bag means 14a is thereby solidly keyed into the channels defined by spaced flanges of the soldier beams, and acts as horizontal sheeting to retain the excavation. Also, the expanded walls of the bag means iill voids behind the excavated area and thereby form a tight seal against soil being protected or shored.

Referring particularly to FIGURES 7 and 8, the expanded shape of the bag means may be controlled during the grout injection step of the method, by positioning rigid, elongated restraining members of bars 2S between the forward flanges 13a, 13a of next adjacent uprights 13, and outwardly of the forward wall of the respective bag means 14, while the hydraulic cement mortar is being pumped in. This added procedure reduces the size of the expanded bag means necessary, and accordingly tends to reduce the cost of materials used.

In severe cases Where iiowable sand exists in the situs, bag means 14 may be forcibly inserted under the last previously placed and inflated bag means, with little or no under-excavating. The so inserted bag means can then be pressure grouted at the same time further under-excavating is performed. The completed wall, as shown in FIGURES 6 and 7, oifers many advantages over so-called wood sheeting, including the fact that the walls of the adjacent superposed bag means 14a are bonded to each other to form tight joints when they are cast in place. Wood sheeting of the prior art, on the other hand, allows tine earth materials to sift through joints or cracks between sections of the same, which tends to undermine the shored area, and requires constant plugging and/or maintenance. The present invention also eliminates the problem of voids formed directly behind such wood sheeting. These voids often caused eventual damaging settlement of earth behind the wood sheeting with resultant shifting of surrounding structures. The grout expanded bag walls of the present invention completely iill the sheeted areas, and tightly conform to the cut-off face portions of the excavation area.

The improved method makes it possible to build a strong, reliable, cast-in-place concrete retaining wall under working space conditions which would otherwise prevent use of bulky pile driving equipment. In other words, an earth retaining wall may be built by the present method with little more than a relatively small, hydraulic-cement, pumping unit, in addition to the usual earth excavating equipment.

In practice of the method described above, there is no time during progressive removal of earth from the excavation cut-off area, when the unexcavated perimeter of earth is not sufficiently supported against unwanted movement of earth into or toward the excavation (see FIG- URES 2 to 6).

Modifications of the invention may be resorted to without departing from the spirit thereof or the scope of the appended claims.

What is claimed is:

1. A method for making a cast-in-place protective wall or barrier, as for retaining the earth around an excavation cut-ofi area in an earth situs, comprising: the steps of providing a plurality of laterally spaced, rigid backing elements, extending vertically within the earth situs; positioning a first tiexible-walled bag means upon the earth of the situs to extend between laterally opposed portions of said elements; pumping pressurized iiuid cement mortar into said rst bag means to expand the walls thereof into tight frictional engagement with opposing structure in the situs including opposed portions of said elements, and allowing said cement mortar to harden and thereby fixedly to support the expanded bag means against said opposing structure; removing earth of the situs 'from irnmediately beneath said fixedly supported, expanded bag means, to form a space thereunder between said elements; positioning and mortar-expanding a second bag means within said space to be likewise iixedly supported against opposing structure including said iirst bag means; and repeating such steps of the process in downward progression as necessary to form a plurality of ixedly positioned bag means to requisite depth within the earth situs.

2. A method as in claim 1, wherein said spaced rigid elements have laterally opposed channel-shaped portions into which portions of said bag means are grout expanded.

3. A method as in claim 2, wherein walls of said bag means are porous, whereby limited amounts of said grout expanded therethrough bonds the bag means to each other and to contacted structure of the situs.

4. A method as in claim 1, wherein walls of said bag means are porous, whereby limited amounts of said grout expanded therethrough bonds the bag means to each other and to contacted structure of the situs.

5. A method as in claim `4, wherein the steps of the method are repeated between series of laterally spaced said rigid elements around at least a substantial peripheral extent of an excavation cut-oti area, and said removal of earth to form the spaces below successive ixedly supported, expanded bag means being coordinated with progressive removal of earth from within said excavation cut-off area.

6. A method as in claim 1, wherein the steps of the method are repeated between series of laterally spaced said rigid elements around at least a substantial peripheral extent of an excavation cut-off area, and said removal of earth to form the spaces below successive iixedly supported, expanded bag means being coordinated with progressive removal of earth from within said excavation cut-ofi area.

References Cited UNITED STATES PATENTS 1,421,857 '7/1922. Store 61-46 3,099,911 8/1963 Turzillo 61-35 JACOB SHAPIRO, Primary Examiner.

U.S. Cl. X.R.

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