US3412562A

US3412562A - Structural wall and method

Info

Publication number: US3412562A
Application number: US682763A
Authority: US
Inventors: Doughty Samuel Clifford
Original assignee: Ben C Gerwick Inc
Current assignee: Ben C Gerwick Inc
Priority date: 1967-11-14
Filing date: 1967-11-14
Publication date: 1968-11-26
Anticipated expiration: 1985-11-26

Description

Nov. 26, 1968 s. c. DOUGHTY 3,412,562

STRUCTURAL WALL AND METHOD Filed Nov. 14, 1967 2 Sheets-Sheet 1 F l g. 6 INVENTOR.

S. CLIFFORD DOUGHTY Attorneys Nov. 26, 1968 Filed NOV. 14, 1967 54 5o 62 I H, L Y

S. C. DOUGHTY STRUCTURAL WALL AND METHOD 2 Sheets-Sheet 2 INVENTOR. S. CLIFFORD DOUGHTY Attorneys United States atent 3,412,562 STRUCTURAL WALL AND METHOD Samuel Clifford Doughty, Burlingame, Califi, assignor to Ben C. Gerwick, Inc., San Francisco, Calif a corporation of California Continuation-impart of application Ser. No. 418,778,

Dec. 16, 1964. This application Nov. 14, 1967, Ser.

Claims. (Cl. 6139) ABSTRACT OF THE DISCLOSURE A structural wall formed with a number of upright and laterally spaced apart H-beam members wherein the span between members is provided relative to the thickness of the wall so as to provide arch action support to the wall when earth on one side of the wall is excavated. After excavation, a finish facing is applied to the exposed wall carried by means attached to the exposed flanges of the H-beam members or by attachment to the concrete. To form the wall, the H-beam members are lodged in the ground as guided by pre-drilled holes formed at intervals and followed by the excavation of material from between the webs of the H-beams. A slurry is maintained in the trench being formed and concrete is poured employing the tremie method.

Cross-reference to related application This application is a continuation-in-part of US. patent application, Ser. No. 418,778, filed Dec. 16, 1964, now abandoned in the name of S. Clifford Doughty.

Background of the invention This invention relates to concrete wall contsructions and to a method of constructing same.

In the construction of large buildings, subways, and other structures in cities, a major problem is the provision of a supporting structure, installed before or during excavation, which will hold back the surrounding ground and provide lateral support to adjacent buildings, streets, etc. In the past this has often been accomplished by the installation of steel sheet piles driven before excavation starts, or by the use of soldier beams and lagging. The latter method has the disadvantage that it drains the surrounding soil, frequently permitting the adjoining buildings to settle. Installation of steel sheet piles is expensive and usually causes considerable vibration and noise.

Another approach has been the construction, before excavation starts, of a concrete wall. This concrete wall can usually be installed with a minimum of noise and vibration and can serve as a part of the permanent wall of the structure. Spaced holes are drilled, then filled with concrete. Later, additional holes are drilled between and filled with concrete. During the hole drilling, a slurry, such as a bentonite slurry, keeps the hole from caving.

Still another method contemplates excavation of a trench in successive sections with a clamshell bucket while the trench is kept filled with a bentonite slurry. The sections are then filled with concrete placed by the tremie method. A reinforcing steel cage is placed in the bentonite slurry before the concrete is poured to provide structural strength later. This latter method is very expensive. The joints between adjacent sections often weep or leak. Further, in very unstable soils, the section of trench that can be excavated at any one time must be kept to a minimum, which therefore begins to approximate the older drilled-hole technique referred to initially above. The only support to the sides of the trench is from the bentonite slurry and is not entirely satisfactory. Further, this method requires much time.

Objects and summary of the invention In general, it is an object of this invention to overcome these and other shortcomings of earlier Schemes and to provide an improved wall construction technique having significant additional advantages, as well.

It is another object of the invention to provide an improved method of constructing a structural wall which is to be subjected to earth pressures acting laterally against it.

It is a further object to provide an improved wall structure according to the invention herein; excavation and also serves thereafter as the structural wall of the construction being erected.

Another object is the provision of an improved wall structure and method for excavations in sandy or other uncertain strata.

These and other objects of the invention will be more clearly understood from the following detailed description of preferred embodiments of the method and wall construction herein.

FIGURES 1 through 5 diagrammatically illustrate in plan view steps of a method of constructing a wall structure according to the invention herein;

FIGURE 6 is a diagrammatic plan view of a wall structure according to the invention herein,

FIGURE 6a schematically representing tremie placement of concrete;

FIGURE 7 is a section view in plan showing a wall construction wherein a finish facing has been attached to concrete portions of the wall; and

FIGURES 8 and 9 are diagrammatic perspective views showing a sequence of steps followed according to another embodiment of the method of the invention.

In general, to construct an improved wall structure according to the invention, a method is provided which, in general, follows the steps of drilling a series of upright holes into the earth. The holes are spaced a predetermined distance apart. An elongate structural member, such as a soldier beam, is next guided into each hole. The next step includes the forming of a trench between the inserted soldier beams whereby the soldier beams serve as trench braces to provide support to opposed walls of the trench. The trench is then filled with a hardenable cementitious material such as concrete to form a wall in the trench.

Ordinarily after permitting the material to harden, earth will be removed from one side of the wall which has the effect of subjecting the wall to earth pressures acting against the unexcavated side of the wall. The thickness of the trench with respect to the span of the wall between each adjacent pair of structural members is sufficiently thick to transmit by arch action the load of earth pressure acting against one side of the wall after the earth is removed from the other side of the wall.

In weak or caving soil a slurry is maintained in the holes so as to seal the exposed surfaces therein. Also, in one preferred form of the method, the hole diameter is such that the beam fits snugly into the hole to support the sides of the hole during excavation between beams.

Description of preferred embodiments One preferred method of constructing the wall proceeds as now to be described with particular reference to FIG- URES l-6 of the drawings.

Initially, the first step includes drilling a series of holes 10 of predetermined diameter, D. The axis of the holes as shown herein is vertically into the earth, and the axes are spaced apart at intervals which, as will be later seen below, define the span, S, of vertical slabs of concrete. A volume of slurry, such as a drillers mud, is maintained in each hole to seal the exposed surfaces therein and provide lateral support to the walls of each hole. A slurry of bentonite is preferable for this purpose. The next step includes inserting a structural steel H-beam member 12 into the slurry in each hole. Beam members each include spaced apart

parallel flange portions

14, 16 and web portions 18 extending normal to the flange portions along the length thereof.

The flanges of adjacent beam members are aligned in spaced

planes

20, 22 to generally define the wall thickness to be formed. The diameter of the holes is comparable to the width of the web portion 18 as shown in FIG- URE 3. The next step includes excavating between the

planes

20, 22 and between the web portions 18 of each adjacent pair of beam members 12 so as to form an elongated trench 24 having opposing

sidewalls

26, 28.

Sidewalls

26, 28 are braced at intervals by the beam members 12. During the foregoing excavating step, suflicient slurry is maintained in trench 24 to seal the exposed surfaces thereof and to give lateral support to prevent cave-in.

The next step is to fill the trench sections, preferably successively between each adjacent pair of beam members 12 with a cementitious material such as concrete using a tremie pipe 29 so as to displace the slurry therein. Subsequently, the cementitious material is permitted to harden so as to form a wall.

As is known in the art, a tremie pipe for the pouring of a wet concrete mix consists of a straight metal pipe or conduit open at both its upper and lower ends, and communicating at its upper end with a hopper into which the wet mix is introduced. At the beginning of the pour the lower end of the pipe is positioned near the bottom of the space to be filled, and as the level of the poured concrete rises about the lower end of the pipe, the pipe is gradually elevated while introduction of concrete continues without interruption.

As is known, concrete may be placed under water through a tremie or watertight pipe 12 in. to 24- in. in diameter, having a conical shaped top the better to receive the charge of concrete. At the start of operations the mouth of the pipe is set on the bottom and the pipe filled with concrete. The pipe is then slowly raised, allowing the concrete to flow out as more concrete is poured in at the top, always keeping the pipe fully charged. It is essential, once the concreting operations are started, that the lower end of the pipe be kept buried in the concrete until the entire operation is completed. In this manner, washing out of the cement is prevented. The upper layer of concrete displaces the Water, and laitance is kept at the surface of the concrete whence it may be finally and effectively removed. If at any time during the operations the bottom of the pipe loses contact with the concrete, the charge will be lost; therefore particular care must be taken in continuing operations not to stir up the fresh concrete in place. Tremie operations should be continuous until the structural unit has been completed.

Tremie concrete must be of a consistency that will ermit it to flow readily and it therefore requires more cement and water than concrete placed in the dry. A conventional slurry of the above type consists mainly of water.

While clamshell or other types of excavators may be used to form the trench portions defined between beams, it is particularly preferred to accomplish the excavation between beam-filled holes 10 by drilling holes 30 intermediate holes 10. For purposes which will become further apparent below it is prefer-red to form holes 10 and 39 with a diameter, D, whereby the thickness of trench 24, as defined between

planes

26, 28, is proportionate to the span, S, of each vertical slab 32 of concrete so as to transmit by arch action (as suggested by lines 34 in FIGURE the laterally acting load of earth which bears against the unexcavated side of the wall.

Thus, each slab 32 includes a portion 33 of concrete active in providing the above mentioned arch action support, and other portions 35 which are inactive as sometimes referred to a dead concrete. Each slab 32 of concrete is positively locked by

flanges

14, 16.

In one particularly preferred construction, the diameter, D, is proportional to the span, S, in a relationship of 1 to 2. Thus, where diameter D is two feet the distance between centers of holes 10 is preferably four feet. The diameter D of holes 30, being comparable to the diameter of holes 10, therefore serves to define wedges of earth 36 which are removed by suitable excavating equipment.

With reference to FIGURE 6, a wall construction formed by the foregoing technique is shown and it will be readily apparent that after the earth is excavated away from one side of the wall sufliciently to expose flange portions 16, attachment means can be welded to the flanges 16 so as to project therefrom and aid in the placing of an inner finish facing 40 of concrete. This may, for example, be about six inches in thickness. Thus, after excavating away from one side of the structural wall, the side of the wall will be thoroughly cleaned off and attachment means such as stud anchors 42 can then be welded to the exposed flanges 16. Stud anchors 42 are bent over atthe end and serve to engage rods 44 of a reinforcing steel matrix 46. After erecting a form to define the inner wall surface 48, the finished wall can be poured.

As shown in FIGURE 7, stud anchors can also be embedded into the concrete portions 35.

From the foregoing, it will be apparent that there is provided a wall construction for imparting lateral support to earth adjacent one side thereof. The wall comprises a series of elongated structural pre-formed beam members such as the H members which are disposed upright in a line. Beam members include spaced parallel sides aligned in spaced parallel planes wherein the planes serve generally to define the thickness of the wall. A vertical slab of poured concrete is formed between the planes and spans the distance between each adjacent pair of beam members so as to engage webs of the beam members. Each slab is sufficiently thick with respect to the span thereof to transmit by arch action to its associated pair of beam members the load of earth pressure acting against the unexcavated side of the wall. Thus, the trench is securely braced at close intervals.

The wall construction forms not only the wall of the structure but at the same time provides a soil support bulkhead also useful during excavation and thereby eliminates considerable duplication of construction expense which conventionally is encountered. The wall construction further provides weldable regions conveniently located so as to provide the attachment means for supporting the finishing facing 40, or in the alternative, wide, accessible zones of concrete where it is preferred to anchor to concrete.

From the foregoing, it will be further evident that the method permits the construction of a soil support bulkhead and a structural wall in uncertain strata by taking advantage not only of the drilling mud but also by utilizing the soldier beams as trench braces during the formation of the wall. These same soldier beams serve to provide a bending support against the earth pressures after the wall is completed and the earth excavated away from one side.

From the foregoing benefits and advantages it will be readily evident that this invention overcomes the difficulties outlined initially above and results in a permanent wall which offers considerable economy in construction. The wall can be constructed much more rapidly and provides a positive trench bracing support during the period of construction. The wall provides further a positive joint between adjacent adjoining sections of the wall and facilitates forming and pouring of an inside facing or finish wall. As also noted above, the wall construction derives vertical bending strength from the soldier beams rather than being dependent on the concrete. Finally, the wall as formed by the above method provides a relatively uniform thickness of wall, which in many cases will permit better clearance and closer approaches to adjoining buildings and structures.

Where ground conditions dictate, it may be desirable or necessary to form the series of drilled holes of a considerably reduced diameter as shown by the holes 50 in FIGURE 8. Thus, the series of holes 50 are aligned along the line 52 adapted to define the central plane of a wall to be formed.

Each of holes 50 serves to guide an elongated H-beam member 54 along the axis of the hole 50 so as to properly maintain the H-beam member 54 in its proper disposition. Thus, the bottom end of H-beam member 54 is provided with an elongated projecting guide element in the form of the cylindrical element 56 formed with a conicallypointed end 58. Element 56 is attached to the lower end of member 54, as by welding.

Accordingly, after drilling a series of upstanding holes 50, H-beam members 54 are formed with a guide element 56 which will cooperate in a guiding relation with respect to holes 50. Subsequently, H-beam members 54 are driven into the earth, guided by elements 56.

In FIGURE 9, the application of a driving force to H-beam member 54 is indicated by the arrow 62. After having lodged members 54 in the earth with the flanges thereof aligned in spaced parallel planes, excavation between the webs of members 54 proceeds as above described with respect to the procedure represented in FIG- URES 16.

By restricting the size of holes 50 to the generally reduced diameter of the guiding element 56, it has been found that in many instances, it is unnecessary to maintain a slurry Within the drilled holes inasmuch as the smaller diameter hole is less subject to caving.

Thus, it will be readily evident that the relatively easily accomplished accuracy of locating the drilled guide holes 50 or the larger diameter holes 10 may be first accomplished and then utilized to properly guide the H-beam members into accurate alignment with respect to other members which will form portions of the wall structure. Where beam driving techniques have been developed to accomplish comparable accuracy, it may, under certain soil conditions, be desirable to merely drive the beams directly into the earth without prior drilling of a guiding hole for receiving the beam.

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in form and details of the embodiment illustrated may be made by those skilled in the art, without departing from the spirit of the invention. For example, some of the foregoing advantages may be attainable utilizing soldier beams such as pipe piles, or pre-stressed or pro-formed concrete beams rather than the H-shaped structural members of the preferred embodiment above.

Therefore, it is the intention to be limited only by the scope of the following claims.

I claim:

1. In a method of constructing a wall structure those steps comprising drilling a plurality of at least two upstanding holes of predetermined diameter into the earth spaced a predtermined distance apart, inserting an elongate structural member into each hole, the dimension of each member in a direction normal to a plane between said holes being comparable to the diameter of said holes to apply support to opposite sides of said holes, forming a substantially rectilinear trench between said inserted members whereby said members serve as trench braces to provide support to opposed walls of the trench, and filling the trench between said braces with hardenable cementitious material to form a wall in said trench, permitting the material to harden, and removing earth from one side of the wall after the material hardens, the thickness of said trench with respect to the span of Wall between said structural members being sufiiciently thick to transmit by arch action the load of earth pressure acting against one side of the wall after the earth is removed from the other side of the wall.

2. The method of constructing a structural wall comprising the steps of drilling a series of holes of predetermined diameter generally vertically into the earth at spaced apart intervals, maintaining a volume of slurry in each hole to seal the exposed surfaces therein, inserting a structural steel H beam member having web and spaced flange portions into each hole, the flanges of adjacent beam members being aligned in spaced planes to generally define the wall thickness, the diameter of said holes being comparable to the Width of the web of the beam member therein, excavating between said planes and the web portions of each adjacent pair of beam members to form an elongated trench having opposing side walls braced at intervals by said beam members, maintaining sufficient slurry in the trench to seal the exposed surfaces thereof, filling the trench portions between each adjacent pair of beam members with cementitious material using a tremie pipe so as to displace the slurry therein, and permitting the cementitious material to harden to form a wall.

3. The method of constructing a structural wall comprising the steps of drilling a series of holes of predetermined diameter generally vertically into the earth at spaced apart intervals, maintaining a volume of slurry in each hole to seal the exposed surfaces therein, inserting a structural steel H beam member having web and spaced flange portions into each hole, the flanges of adjacent beam members being aligned in spaced planes to generally define the wall thickness, excavating between said planes and the web portions of each adjacent pair of beam members to form an elongated trench having opposing side walls braced at intervals by beam members, maintaining sufficient slurry in the trench to seal the exposed surfaces thereof, filling the trench portions between adjacent pairs of beam members with cementitious material using a tremie pipe so as to displace the slurry therein, and permitting the cementitious material to harden to form a wall, followed by the further steps of excavating the earth away from one side of the wall to expose said flange portions, and leaving the other side of the wall to remain under lateral earth pressure acting thereagainst.

4. The method of constructing a structural wall comprising the steps of drilling a series of holes of predetermined diameter generally vertically into the earth at spaced apart intervals, maintaining a volume of slurry in each hole to seal the exposed surfaces therein, inserting a structural steel H beam member having web and spaced flange portions into each hole, the flanges of adjacent beam members being aligned in spaced planes to generally define the wall thickness, the diameter of said holes being comparable to the width of the web of the beam member therein, excavating between said planes and the web portions of each adjacent pair of beam members to form an elongated trench having opposing side walls braced at intervals by said beam members, maintaining sufficient slurry in the trench to seal the exposed surfaces thereof, filling the trench portions between each adjacent pair of beam members with cementitious material using a tremie pipe so as to displace the slurry therein, and permitting the cementitious material to harden to form a wall, wherein said excavating step is performed by drilling generally vertical holes into the earth between each adjacent pair of the first named holes, and thereafter removing any remaining unexcavated earth lying between said planes.

5. In a method of constructing a wall structure, the steps comprising: drilling upstanding spaced apart holes in the earth, inserting H-beam members into the holes, said members including a web portion extending longitudinally therealong and spaced parallel flanges, the flanges being snugly received in said holes and lying in spaced parallel planes to substantially define the thickness of the wall structure, excavating earth from between said members to form a trench, filling the trench defined between two adjacent H-beam members in said trench with a hardenable cementitious material to form a Wall portion in said trench, the spacing between said two adjacent H-beam members being related to the wall thickness to define the span and thickness of the Wall portion therebetween sufficient to provide arch action support to the load of earth pressure acting against one side of the wall portion when earth on the other side has been removed, permitting the cementitious material to harden, and removing earth from one side of the wall after the material hardens,

6. In a method of constructing a wall structure, the steps comprising: drilling upstanding spaced apart holes in the earth, guiding H-beam members into the holes, said members including a web extending longitudinally therealong between spaced parallel flanges, the flanges lying in spaced parallel planes to substantially define the thickness of the wall structure, excavating earth from between said members to form a trench, filling the trench defined between two adjacent H-beam members in said trench with a hardenable cementitious material to form a wall portion in said trench, the spacing between said two adjacent H-beam members being related to the wall thickness to define the span and thickness of the wall portion therebetween sufficient to provide arch action support to the load of earth pressure acting against one side of the wall portion when earth on the other side has been removed, permitting the cementitious material to harden, and removing earth from one side of the wall after the material hardens.

7. In a method of constructing a wall structure, the steps comprising: lodging upstanding spaced apart H- beam members in the earth, said members including a web portion extending longitudinally therealong and spaced parallel flanges, the flanges lying in spaced parallel planes to substantially define the thickness of the wall structure, excavating earth from between said members to form a trench, filling the trench defined between two adjacent H-beam members in said trench with a hardenable cementitious material to form a wall portion in said trench, the spacing between said two adjacent H-bearn members being related to the wall thickness to define the span and thickness of the wall portion therebetween sufficient to provide arch action support to the load of earth pressure acting against one side of the wall portion when earth on the other side has been removed, permitting the cementitious material to harden, and removing earth from one side of the wall after the material hardens.

8. In a method of constructing a wall structure, the steps comprising: drilling upstanding spaced apart guide holes in the earth, forming H-beam members at one end thereof with an elongated projecting guide element adapted to cooperate in guiding relation with said holes, inserting said guide elements of said H-beam members into the holes and driving said H-beam members into the earth guided by said elements, said H-beam members ineluding a web portion extending longitudinally therealong and spaced parallel flanges, said flanges lying in spaced parallel planes to substantially define the thickness of the wall structure, excavating earth from between said members to form a trench, filling the trench defined between two adjacent H-beam members in said trench with a hardenable cementitious material to form a Wall portion in said trench, the spacing between said two adjacent H-beam members being related to the wall thickness to define the span and thickness of the wall portion therebetween suflicient to provide arch action support to the load of earth pressure acting against one side of the wall por tion when earth on the other side has been removed, permitting the cementitious material to harden, and removing earth from one side of the wall after the material hardens.

9. A wall construction for providing lateral support to unexcavated earth bearing against one side thereof where earth has been excavated away from the other side thereof, said wall comprising a series of structural steel H-beam members disposed upright in a line and formed with spaced parallel flange portions lying in spaced parallel planes, said H-beam members further including a web portion disposed normal to the flange portions, the spacing between said planes substantially defining the thickness of the wall, an upstanding slab of tremie-poured concrete formed between said planes and spanning the distance between each adjacent pair of said webs to engage said beam members, the front and back surfaces of said slab lying substantially in said planes, each slab being sufficiently thick with respect to the span thereof to transmit by arch action, defined between said planes, to the webs of its associated pair of beam members the load of earth pressure acting against the unexcavated side of the wall, the wall on the excavated side thereof being exposed, attachment means projecting from the exposed side of the wall, and an inner finish facing forming a finished wall surface on the excavated side of the wall, said attachment means being embedded in said facing to support said inner finish facing.

10. A wall construction according to claim 9 wherein the exposed side of the wall includes exposed flange portions of said H-beam members, and said attachment means projects from said exposed flange portions to support said inner finish facing therefrom.

References Cited UNITED STATES PATENTS 592,738 10/1897 Judson 61-39 2,791,886 5/1957 Veder 6135 3,184,893 5/1965 Booth 52l69 X 3,216,163 11/1965 Carew 52-169 X FOREIGN PATENTS 1,127,500 8/1956 France.

OTHER REFERENCES Roads and Streets (publication), November 1962, pp. 21, 22 and 23.

JACOB SHAPIRO, Primary Examiner.

Disclaimer 3,412,562.Smuel Clifford Doughty, Burlingame, Calif. STRUCTURAL WALL AND METHOD. Patent dated Nov. 26, 1965. Disclaimer filed Jan. 23, 1980, by the assignee, Santa Fe-Pomeroy, Inc. Hereby enters this disclaimer to claims 9 and 10 of said patent.

[Ojficz'al Gazette, May 6, 1.980.]