US3606757A

US3606757A - Method for laying pipe

Info

Publication number: US3606757A
Application number: US848618A
Authority: US
Inventors: Lloyd De Weese; Marilyn Langston De Weese
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-06-21
Filing date: 1969-08-08
Publication date: 1971-09-21
Anticipated expiration: 1988-09-21

Abstract

METHOD FOR LAYING LARGE DIAMETER CONCRETE PIPE IN AN EXCAVATION OF MINIMUM WIDTH WITH MAXIMUM SAFETY PROVIDED FOR THE PERSONNEL LAYING THE PIPE INCLUDES THE STEPS OF DIGGING A PARTIAL TRENCH, INSERTING AN EXCAVATING CAGE THEREIN, COMPLETING THE DITCH AND LOWERING SLIDING INDIVIDUAL CANTILEVERED SHEAR MEMBERS TO REINFORCE THE SIDE WALLS OF THE TRENCH, LAYING THE PIPE AND DIGGING AN ADJACENT PARTIAL TRENCH, RAISING THE SHEAR MEMBERS AND ADVANCING THE CAGE INTO THE ADJACENT PARTIAL TRENCH AND THEN REPEATING THE CYCLE. THE EXCAVATING CAGE IS A RIGID FRAME HAVING A LARGE UNOBSTRCUTED CENTER TO PERMIT COMPLETION OF THE EXCAVATION THEREIN WITH A BACK HOE. THE VERTICALLY SLIDABLE SHEAR MEMBERS ARE RIGIDLY SUPPORTED IN GUIDE SLOTS AND ARE CAPABLE OF WITHSTANDING THE SUBSTANTIAL PRESSURES IN THEIR EXTENDED POSITION WITHOUT BEING CROSS BRACED, AND A REAR SHIELD IS PROVIDED TO PERMIT BACK FILLING OF THE EXCAVATION.

Description

Sept. 21,1971

1.. J. DE WEESE F METHOD FOR LAYING PIPE 4 Sheets-Sheet 1 Original Filed June 21, 19s? FIG- 2 103% INVENTORS LLOYD J. DIWEESE a M. LANGSTON DIWEESE BY t ,fiwv w ATTORNEYS Sept. 21, 1971 5 wEESE ETAL 3,606,757

METHOD FOR LAYING PIPE 4 Sheets-Sheet 2 Original Filed June 21, 1967 w 1 o\ 5 1O 4 mm w F 6 u z w 2 s H w v m 3 1 m G H 8 m a? 1 2 FIG-4;

m a m Sept. 21 1911 DE WEESE ETAL 3,606,757

METHOD FOR LAYING PIPE Original Filed June 21, 1967 4 Sheets-Shoot S FIG-7 104 Se t. '21, 1971 L. J. DE WEESE METHOD FOR LAYING PIPE 4 Sheets-Sheet 4 Original Filed June 21. 1967 7 7 .Q G Hm 0 /1. M m w A if z m a 1 2 4 9/ MIA .b a G W H w 2 8 a w 1 3 8 5 10 W 3 W O 2 \Y .l 05 w w& a F .5 o 1.6 .1 mfilll wu 2 6 u 4 x fl 1 at 6 5 6 United States Patent U.S. C]. 61-41 Claims ABSTRACT OF THE DISCLOSURE Method for laying large diameter concrete pipe in an excavation of minimum width with maximum safety pro vided for the personnel laying the pipe includes the steps of digging a partial trench, inserting an excavating cage therein, completing the ditch and lowering sliding individual cantilevered shear members to reinforce the side walls of the trench, laying the pipe and digging an adjacent partial trench, raising the shear members and advancing the cage into the adjacent partial trench and then repeating the cycle. The excavating cage is a rigid frame having a large unobstructed center to permit completion of the excavation therein with a back hoe. The vertically slidable shear members are rigidly supported in guide slots and are capable of withstanding the substantial pressures in their extended position without being cross braced, and a rear shield is provided to permit back filling of the excavation.

RELATED APPLICATION This application is a division of application Ser. No. 647,692, filed June 21, 1967, nOw Pat. No. 3,496,727.

BACKGROUND OF THE INVENTION In the digging of deep trenches for laying of large pipe and the like, it is necessary to provide reinforcement to the side walls of the trench for the purpose of limiting the width of the trench so that the adjacent water and sewer lines are not disturbed and so that safety is provided for the personnel laying the pipe. The reinforcement has heretofore been provided by driving H-beam pilings and then starting the excavation. Sheeting is placed behind the pilings and Whalers across the trench as the excavation is dug. This procedure is both time consuming and expensive. The present invention is thus directed to an improved method for laying large diameter pipe at a comparatively fast rate while providing reinforcement of the side walls of the trench.

The pertinent prior art to this invention includes the patents to De Lillo, Nos. 3,159,977 and 3,159,978, both issued Dec. 8, 1964, and Benintend No. 3,212,270, issued Oct. 19, 1965. Each of these patents is designed for laying pipe of a much smaller diameter than contemplated by the present invention. Moreover, in each of them the opening defined by the side walls is obstructed by cross members which are necessary for reinforcing the side walls.

In particular, De Lillo No. 3,159,977 utilizes telescoping side members having cross members therebetween. The telescoping side members cannot be lowered into position until the excavation is completed so that special problems are involved when the excavation is being made through loose gravel or wet soil. The cross members prohibit use of a back hoe or the like to remove dirt after the shoring device is installed. Similarly, De Lillo No. 3,159,978 uses telescoping side members which again cannot be driven downwardly and the cross members obstruct the removal of the dirt. Neither of the De Lillo devices uses an end frame but rather the side members are adjustably positioned on the cross members which are supported on opposite sides of the trench.

In Benintend, the side walls are formed by large sheet metal plates which are dropped in position after the excavation is completed. Cross members are again required to provide lateral support to the side plates since these plates are not strong enough to withstand the forces of the side walls. These cross members obstruct the center of the excavating device and prohibit digging after the side walls are lowered. Moreover, the Benintend structure is intended for use in laying small diameter concrete pipe and thus has not solved many of the problems raised in laying a large diameter pipe, for example, 10 to 12 feet in diameter.

SUMMARY OF THE INVENTION The invention relates to a method for laying large diameter concrete pipe in sections and includes an excavating cage which is utilized to lay the individual sections of concrete pipe. The cage is rigid in construction and has an unobstructed center so that the excavation can be completed without moving the cage. One end of the cage is provided with a configuration to permit excavation to a substantial depth with a back hoe while the other end thereof is provided with a pivotal shield which permits back filling after the cage has been advanced.

The method contemplates digging a partial trench, inserting the cage, driving individual shear members vertically downwardly through guide members, completing the excavation by removing dirt through the unobstructed center of the cage, laying the pipe through the unobstructed opening, partially back filling to secure the pipe in position, raising the shear members until their lower ends no longer extend below the lower ends of the cage, advancing the cage into a previously dug adjacent partial trench, and repeating the operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the excavating cage in accordance with the invention;

FIG. 2 is a partially dug trench ready to receive the excavating cage;

FIG. 3 is a view similar to FIG. 2 with the excavating cage in the partial trench;

FIG. 4 is a sectional view taken through the trench showing the completion of the digging operation;

FIG. 5 is a transverse sectional view showing the pipe being laid in position;

FIG. 6 is a view similar to FIG. 5 showing the initial filling of the trench;

FIG. 7 is a longitudinal sectional view showing the preparation of the adjacent partial trench;

FIG. 8 is a view similar to FIG. 7 showing the movement of the excavating cage;

FIG. 9 is an end view, partially in section, of the cage taken along the line 99 of FIG. 10;

FIG. 10 is a view of the excavating cage taken along the line 1010 of FIG. 9; b FIG. 11 is an elevational view of one of the shear memers;

FIG. 12 is a vertical sectional view through the coupling used to raise the shear members;

FIG. 13 is a sectional view through one of the shear members mounted in place; and

FIG. 14 is a sectional view taken along the line 1414 of FIG. 13.

DESCRIPTION OF THE PREFERRED EMBODIMENT The apparatus will first be described and followed by the method of the invention and the operation of the apparatus. Accordingly, FIG. 1 illustrates the excavating 3 cage in accordance with the invention including parallel side walls 12 which are identical in construction and interconnected by the back and

front walls

13 and 14. Each of the side walls 12 includes the parallel

upper members

15 and 16 in the form of H-beams having welded therebetween the downwardly extending parallel guides 18 (also H-beams) which are also rigidly welded to the lower horizontal H-beam member 20 (FIG. 9).

A metal plate or skin 22 is welded to the outside surfaces of the flanges 23 of the guide 18 and this plate is of suflicient size to cover completely the entire side of the cage except for the upper member 16. Guide slots 25 are thus formed between the adjacent guides 18 with the

flanges

23 and 26 of the H-beams providing restrictions which limit the movement of the slidable shear members 28 therein, as will be seen.

The back wall 13 of the cage 10 includes the parallel upper and

lower members

31 and 32, also in the form of H-beams, which are secured to the inside of the upper and

lower side members

15 and 20 of the side walls and braced by the

corner members

33 and 34. The

cross braces

35 and 36 provide additional strength to the rear wall and extend in a criss-cross pattern from weld connections adjacent the juncture of the upper and

lower members

15, 31, 20 and 32. A central plate 38 is utilized to reinforce the

cross braces

35 and 36 at the point at which they cross.

A pivotal rear shield 40 (FIG. 4) is secured on the rear wall 13 to facilitate back filling, as will be described. It is mounted on brackets 41 secured to the rear guides 18a below the upper member 31. This shield is fabricated from interconnected panels of ribbed metal and extends downwardly beyond the lower member 32 and has the central portion 43 thereof removed to accommodate the concrete pipe 44, as shown in FIG. 5. This wall is adapted to pivot in a counterclockwise direction, as viewed in FIG. 7, about the pivot bracket 41 whereas it engages the

cross members

35 and 36 and the lower member 32 to limit movement in the clockwise direction. A pair of skids 42a having the curved contact plates 42b are provided on the lower member 32 for partially supporting the cage 10 on the pipe 44.

The front wall 14 is an important part of the invention and is designed to permit excavation through the unobstructed central opening 45 by a conventional back hoe. Accordingly, this wall includes the

vertical side members

46 and 47 rigidly welded between the upper and

lower side members

15 and 20 and the lower horizontal member 48 which is secured between the front ends of the lower side members 20. A diagonal member 50 extends downwardly from each of the upper side members 15 to a rigid connection the lower member 48 at points spaced from its end about one-third the width of the cage. Another horizontal member 52 is rigidly welded between the centers of these diagonal members 50 so that there is no obstruction to the upper half of the front wall 14. The four intermediate braces 53 provide additional rigidity to the front wall.

The slidable shear members 28 are shown in detail in FIGS. 11-14 and include a pair of side and center H-

beams

55 and 56 which extend vertically the entire length of the shear members. The metal plates 58 are rigidly welded to the outer surface of the flanges 59 of these members to create relatively flat side walls on the shear members. The lower end of the members 28 is tapered, as shown in FIGS. 9 and 11, and a flat plate 61 secured thereto to thereby create a cutting edge 62 on the lower end of the shear members.

The upper end of the shear members 28 has a heavy striking member 64 in the form of a section of railroad track welded thereto, as shown in FIG. 12, to provide means for driving the shear members 28 into place, and this striking member extends the entire width of the shear member (FIG. 11). In addition, the upper portion of each shear member has a series of openings 65 therein 4 having tubular pipes 66 extending completely therethrough to receive the locating pins 67 so that the downward movement of the shear members 28 is limited by contact between the pin 67 and the top edges 68 of the

upper members

15 and 16.

The uppermost opening 65 is utilized to raise the shear members by placing the lifting assembly or coupling 68 over the top of the shear member and inserting the elongated pin 70 through the openings 71 in the side walls 72 of the coupling 68 and the upper opening 65. The bottom edges 74 of the side walls 72 are tapered outwardly to facilitate mounting on the shear member 28 and a locking strap 75 may be provided to secure the pin 70' in place. The upper portion 76 of the coupling has an opening 77 through which a cable is attached for lifting by a suitable crane.

The method in accordance with the invention and the operation of the excavating cage 10 include the initial step of digging a partial excavation or trench 101 having a width and length slightly .greater than the respective width and length of the cage 10, and a depth substantially equal to the height of the cage, as shown in FIG. 2. The entire cage 10 is then placed into the partial trench, and then the individual shear members 28 are inserted into each of the guide slots with a pin extending through the lowermost opening 65 to hold the shear members 28 in their raised position so that the lower edge 62 thereof does not project below the lower side members 20. Once the cage is in the partial trench 101, as shown in FIG. 3, the sides of the trench 101 are back filled against the skin 22 of the cage 10 to provide suflicient pressure thereon to hold the cage in position as the digging is continued.

Since the partial trench 101 has a length only slightly greater than the length of the cage, a conventional back hoe can be placed on the top surface 103 of the ground closely adjacent the front 14 of the cage 10 and utilized to remove the remaining dirt and complete the excavation through the unobstructed opening -45. The lowered or cut-away front wall 14 permits the arm 104 and bucket 105 of the back hoe to reach deep into the excavation and remove the dirt substantially vertically below the front wall 14 as well as in the rear portion of the trench. As the lower portion 106 of the excavation is being dug by the back hoe, the shear members 28 slide by their own weight or are forced downwardly to reinforce the walls 107 thereof.

The back hoe may be utilized to tap the striking members 64 on the shear members 2 8 to drive them downwardly so that the lower edges 62. of these shear members are always moved downwardly with the depth of the excavation and thus the shear members are always aligned with the bottom contour of the trench. Since the taper 61 on the lower ends of the shear members 2 8 is on the inside thereof it provides a cutting action so that the dirt on the walls 107 is caused to crumble forward into the excavation as the shear members 28 move downwardly thus facilitating the excavation of the trench 106. The shear members 28 ride smoothly in the guide slots 25 of the side walls of the housing with the flanges 26 of the guide 18 limiting the movement of the shear members 28 except in a vertical direction. The skin 22 prohibits dirt from the walls 107 from entering the guide slots 2-5 and obstructing vertical movement of the shear members 28.

Once the lower trench 106 is completed, the back hoe immediately commences digging of an adjacent partial trench 101a having substantially the same dimensions as the aforesaid partial trench 101 and being located immediately adjacent the front 14 of the excavating cage 10, as shown in FIG. 7. As this dirt is being removed, and if it is a suitable quality, it is loaded on to a truck and moved to the rear of the cage 10 to back fill the excavation immediately behind the cage 10, as will be further described. At the same time, other workmen utilizing a crane lower the large pipe sections 44, e.g., 12. feet in diameter, into the completed trench by using a connection assembly 109 extending through openings in the pipe sections and supported by the cables 110 of a crane. As the pipe sections 44 are lowered into the excavation, they are aligned and interconnected and the dirt 111 is tamped at the opposite sides of the trench up to the spring line or the widest portion of the pipe sections 44, as shown in FIG. 6. This is necessary to hold securely the pipe 44 in place since the succeeding back filling operation might well disturb the location of the pipe or might not completely fill the area below the spring line of the pipe.

Once the adjacent partial trench is completed and the number of pipe sections 44 laid in the completed excavation, the shear members 28 are raised by attaching the coupling 68 thereto and individually raising them so that the lower edge 62 does not project below the lower side members 20. The pins 67 are used to secure the members 28 in this raised position and, when all of them have been raised, the cable loop 112 having its ends secured to the rear of the lower side members 20- is connected to a crane and the short cables 113 on the front ends of the lower member 20 are hooked onto the hook 114 on the back hoe, and the entire cage is moved forward. The crane need not be of a size capable of lifting the cage 10, but merely sufficient to take some of the weight off the pipe 44, as the skids 42a support the rear portion of the cage on the previously laid pipe as it is advanced. Likewise, the back hoe primarily provides a horizontal movement although some lifting is present, and the plates 115 ('FIG. 10) on the leading edges of the side walls 12 facilitate entry into the adjacent partial trench 101a. The

cables

112 and 113 are also used to lift the entire cage 10 by a single hook of a crane since these cables will reach to the center of the cage.

Once the cage 10 is in the adjacent partial trench 101a, the back hoe commences to dig the lower portion 106 of the trench to complete the excavation with the shear members 28 being lowered, as discussed above. The removed dirt is loaded into trucks and transported to the trench from which the cage was just removed wherein it is dumped over the pipe 44. As the previous trench is filled, the shield 40 on the rear wall 31 which extends below the cage 10 and almost reaches the dirt 111 tamped around the pipe 44 prohibits the fill dirt from falling into the trench presently being completed and Worked in. The sequence of this operation continues until the entire pipe line has been completed.

Accordingly, the method of this invention permits use of the expensive equipment in the form of a back hoe and crane to be utilized at their maximum efliciency since they do not stand idle more than a short period during the laying of this pipe. It has been found that by using this method, as many as twelve pipe sections can be laid in one day as opposed to three sections by the conventional methods. The shear members cooperate with the guide slots to provide a rigid cantilevered support for the side walls of the lower portion of the trench which requires no cross bracing as present in the prior art even when hundreds of thousands of pounds of pressure are exerted thereon.

The shearing effect of the lower end of the shear members 28 cuts a vertical side wall and facilitates the digging of the trench since the earth is crumbled inwardly with little or no disturbance oh the earth outside of the shear members 28. vMoreover, the configuration of the front wall permits the use of a conventional back hoe to complete the lower portion of the trench as opposed to a clamshell on a crane as heretofore required. in addition to the above, the excavating cage causes a substantial reduction in the width of the trench which must be dug thereby permitting laying large diameter pipe in a narrow right of way and reducing the cost of laying the pipe since the adjacent utility lines are not disturbed and therefore do not require repair or replacement.

While the method herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise method, and that changes may be made without departing from the scope of the invention.

What is claimed is:

1. A method for continuously laying large diameter pipe comprising digging a partial trench having present depth, width and length, inserting an excavating cage in said partial trench to reinforce the side walls of said partial trench,

lowering a plurality of individual shear members, which are narrow in relation to their length, one at a time vertically downwardly through guide members in the opposite sides of said excavating cage to position said shear members in the earth beneath said partial trench, removing the earth between the lower portions of said positioned shear members through the unobstructed center of said cage to form a completed trench whose sides are supported by said positioned shear members,

inserting the pipe section through the interior of said cage into the completed trench,

preparing an adjacent partial trench at one end of said excavating cage,

raising said shear members upwardly until the lower ends thereof no longer extend below the lower ends of said cage,

advancing the cage horizontally into said adjacent partial trench, supporting the rear portion of said cage at least partially on a pipe section previously laid, and

repeating the steps of lowering said shear members downwardly, removing the earth and inserting the pipe sections.

2. The method of claim 1 including the step of securing said shear member in the raised position prior to advancing said cage.

3. The method set forth in claim 1 wherein said removing and preparing steps occur substantially simultaneously for maximum equipment use and speed.

4. The method set forth in claim 1 further including the steps of backfilling and tamping earth around the inserted pipe section at least to the spring line of the pipe section to secure the pipe section in place.

5. The method as set forth in claim '1 wherein said removing step includes transporting the earth removed from said adjacent partial trench to backfill the trench from which the cage has just been advanced.

References Cited UNITED STATES PATENTS 2,777,294 1/1957 Rosa et a1 6141 2,796,738 6/1957 Moore 6l-4l 3,159,977 12/ 1964 De Lillo.

3,159,978 12/ 1964 De Lillo.

3,212,270 10/1965 Benintend.

3,377,806 4/1968 Morrice 61-41 JACOB SHAPIRO, Primary Examiner U.S. Cl. X.R.