US1642213A - Construction of concrete piles or foundation elements - Google Patents

Description

Sept. 13, 1927. 1,642,213

A. R. NEELANDS ET AL f CONSTRUCTION oF CONCRETE PILES 0R FOUNDATION ELEMENTS 2l Sheets-Sheet 1 Filed April 2l. 1925 E ya 4/ J n l n h L ntu...--i?, wf w 4 I v 1,642,213 Sept- 13 1937' A. R. NEELANDS E1' AL CONSTRUCTION OF CONCRETE PILES 0R FOUNDATION ELEMENTS Filed April 21, 192

Patented sept. 13, 1927.

AUNITED STATES ICE.

.ABBAM RUPERT NEELANDS AND GEORGES DAMRY, OF DON CASTEB., ENGLAND,

CONSTRUCTION 0F CONCRETE PILES 0R FOUNDATION ELEMENTS.

Application led April 21, 1925, Serial No. 24,741, and in Great Britain September 25, 1924.v

It has been proposed to construct concrete piles or foundation elements by vboring a hole in the ground untill a stratum of rock, gravel or other suitable supporting material is reached or until the depth of the hole in the ground is suficient to give a, safe bearing area to the pile to be cast later in this hole without necessarily reaching a stratum of rock or solid ground; providing the bore hole With a metal casing which serves as a temporary lining pipe, introducing concrete into the bore hole, and ramming or battering the concrete so that it not only ills the bore hole but is pressed or forced to expand laterally. into the ground surrounding the bore hole by the combined action of the ramming operation and the intermittent or continued lii1`ting of the lining pipe, this process bein repeated or continued until the pile has een formed. y

As the exterior surfaces of piles` constructed in this' manner are irregularly shaped, according to the nature ot the ground in which they are formed, and as their diameter is larger than the diameter ot' the temporary lining pipe, their bearing capacity is greater than that of piles constructed by other methods. lVhen forming concrete piles of this character, a finished mixture of cement and aggregate, forming a complete concrete is rammed into the bore hole, and, as it has been found that piles constructed in this manner cannot be employed ver-y effectively in very soft and issured ground as the concrete cannot expand further than 'the cavity or hole bored or drilled to receive it and the chief object I of the present invention is to provide an improved method of forming piles or foundation elements in issured, soft or heavily water logged ground.

According to the present invention, and in lieu of employing concrete or a finished mixture of cement and aggregate as the tilling material, a concrete pile is produced by forming a bore hole, litting it with a tem'- porary lining tube and injecting liquid cement or the like under pressure into a mass of gravel, ballast or the like previously rammed in place in the ground. By proceeding in this manner a pile can successfully be formed in loose, soft or heavily logged ground intimately welded or fastened into the bore hole containing it v'and substantially rooted into the surrounding strata.

In constructing the pile according to the the hole ensures a suiiicient bearing area for the pile, a suitable casin tube being placed Within the bore hole asllioring proceeds. or

after the completion of the same, according to circumstances. A number of vertically disposed steel tubes of'suitable diameter and perforated along their length are now inserted into the bore hole and on the full depth of same. Thereafter clean gravel,-bal last or any other suitable material is introduced in limited quantities and rammed in place so that it is forced to expand laterally into the surrounding strata, the casing being lifted intermittently or continuously during the ramming operation.

The ram, which is preferably cylindrical, is perforated vertically with a number of holes, corresponding to the number of upright steel tubes employed, so that the ram is free to slide along the tubes which thus may act as guides 'during its up-and-down movement. When, for example, the hole has been lled up to ground level with gravel or ballast and after the casing tube has been entirely removed from the hole, liquid cement or a mixture of cement and Water in suitable proportions or any suitable matter susceptible of setting later may now be introduced through the perforated tubes by means of a suitable grouting or pumping plant, or by compressed air or any other method.

In order that thev said invention may be clearly understood and readily carried into elfect the same will now be described more fully with reference to the accompanying drawing which illustrates diagrammatic-ally and by way of example one method of carrying the invention into practice, and 1n which Figure l is a. longitudinal section taken on the line b-b of Figure 2 showing a bore hole ready to receive the ballast.

Figure 2 is a cross section on the line cb-a of Figure 1.

Figure 3 is a longitudinal section of the ballast rammer, the section'being taken on the line c-c of Figure 4. A

Figure 4 is a horizontal cross section taken on the line rZ-d of Figure 3.

Figure 5 is a longitudinal section taken on the line -e--e of F`- ure 6 showing the pille during the course olconsiaucion.

Figure 6 is a horizontal cross section taken on the line f-f of Figur-e 5. Figure 7 is a longitudinal section showing the bore hole lfilled with ballast and ready to receive the liquid cement.

For the purpose of the example illustrated in. the drawing it* has been assumed 'that it i'sdesired to form la reinforced pile in a sec tion of ground comprising the following stratanamely, a surface deposit of soil l, followed ibya lbed of hard clay 2, land a 'bed -of loose ound, sand, quidk sandv made up ground, ry or Water bearing strata. 3, the flatter resting upon a 'bed of hardrock 4.

5 l'is`the casing vtube and '6 is the cutting edge .at the lower end thereof. 7, are four tubes 'which 'are' 'perforated along their length with small holes, the tubesbeing employed for the 'injection 'of liquid cement 'and as .reinforcements for thepile. '8 is the rammer i'tted at its 'upper end with a swivd elling shackle 'for attachment to the rope or .rod '9 tby' which' the rammelis Suspended. The ramm'erfis perforated along its Ylength wit'hffour holes 10, l10 of a diameter suficient to allow the four tubes 7, l7 to pass freelyA therethrough. The injection tubes 7 ,V 7 are connected to the cementation p'lantlby means of suitable piping 18, 18 flexible or rigid aS referred.

he first operation consists in boring or drilling -into the ground where the concretel pile is .tube formeda circular hole of a suitable diameter. The method vof yboring and, drilling the hole is chosen according tothe nature of thestrata and in fthe example shown the borehole is vdeepened until it penetrates a few feet or so into the solid rock 4 on which the base olf the pile is to rest. The bore hole is then lined or cased from the ground-surface Adown to the solid rock with the circular casing tube 5., the latter being lmade'of steel, iron or .any other suitable material, and may be .flush jointedv and built up in sections of convenient lengths. The placing of the casing tube 5 in position within the bore hole is carried out either asboring .proceeds or after its completion according to the nature of the strata encountered.

The boring being completed andan opening having been formed which penetrates a vfew feet or so into the solid rock-4, and the steel casing having been located' in place, the vsecond operation consists in theconstruction of the-'pile in. the bore hole wliihi.s ready to receive it.

To this end the four hollow and perforated tubes 7, 7 are placed vertically int-o the bore hole so -thatthcy rest upon the bottom of the same.`

A certain Vquantity of ballast is then placed in the bottoin offthe 'bore hole i.fe., inthat part excavated in the solid` rock 4 and this ballast is well rammed in place by means of the rammer 8. The rammer slides freely lalong the reinforcing bars 7 ,l 7-wh-ich consequently act as .guides during itsv upand-d'ownfrnotion, and they necessary motion 1s imparted to the rammer by lany convenient orsuitable method. f

The first load of ballast'introduced into the bore hole having been sufficiently rammed and compressed the rammer 8 is lifted above 'ground level in order to allow' the introduction of a new load ofballastinto the bore hole which in turn 'is rammed in place. these operations 'being repeated untilthe'leve'l of the compressed ballast eachesjthe level of "the solid rock, which is also as previously explained the level of the cutting edge of the steel casing 6. i'

The building up of the reinforced pile .is now continued throughrth'e loose ground, sand, quick sand or water bearing'st-rata 3 in the following manner A'new load of ballastis introduced -into the bore hole'and rainmed'in place by'the rammer .8. As the ramming proceeds' the steel tube 5 is lifted to a certain height above 'the level of the rook 4` this operation being carried on in any suitable manner: 5Onlift -ing the casing 5 to a` suitable heightit'he ballast last Aintroduced into the hole is placediin intimate contact with the surrounding strata, and this fact combined with the'continuation of the energetic ramming causes a lateral expansion of theballast into the loose ground 3 vover a height or distance comprised between the levell of the solid rock 4 and thc bottom of the cutting edge G-iofV the steel casing 5. As this lateral expansion progresses new loads of freshl ballast are introduced into the hole until the expanded pile has reached at that level a diameter known calculated or estimated to -Ibe sufficient for the fpurpose.

W'hen .the fresh ballast last introduced has been 'rammed in place and Whenits expansion has reached the required diameter, a further quantityof' ballast is introduced into the bore hole, the casing bein lifted higher .up and the operations above escribed being continued until the reinforced and compressed pile has reached the height of the` ground level.

In order to maintain the reinforcing bars lll 7, 7 of the pile at a correct and constant distance apart-during the ramming of the ballast into place, ties 13, 13 are introduced into the bore hole and located around the reinforcing bars, the ties being pressed into the fresh ballast last introduced by the action of the rammel'.

The perforated tubes 7, 7 are now coupled up to a pumping or grouting plant,

and liquid cement is forced along the same. From the perforated tubes the liquid cement 'penetrates first into the cavities of the gravel When the final quantities. of liquid cementV are injected the spaces in the gravel or ballast itself are filled up so that it is very closely and intimately embedded into the strengthened surrounding strata, while, in

the case of water bearing strata., the Water originally present in the strata isw expelled to a safe distance from the pile. The liquid cement or otbe'r'binding material `may be forced into the ballast gravel or other filling material at any time either at the completion of the filling of the bore hole as abovedescribed or in stages during the filling of e the bore hole or continuously and conjointly with the filling in of and ramming of the gravel ballast, &c. l The tubes through which lthe liquid Vcement has been injectedserve as reinforce' ments for the pile and their upper ends need not level. with the ground but may proi f ject to any desired height above this level and be incorporated :1s-reinforcing elements in the buildings, structures pr the'like erected upon and supported by the piles.4

Int-he drawing Figures 1 and 2 represent the bore hole completed and penetrating to a certain depth into the solid rock 4, the casing tube 5 having been placed in the bore hole in order to prevent the sides thereof from falling in and the cutting edge 6 resting upon the solid rock 4. The four perforated tubes have also been .placed into the bore hole.

Figures 5 and 6 represent the pile duringthe course of construction. The bottom part of the hole bored into the solid rock 4 has been filled with ballasting 11, a further quantity of fresh 'ballasting 12 has been introduced into the bore hole, the casing tube 5 has been lifted to a certain height and the additional quantity of ballasting l2 is being forced to expand into the loose ground 3 by the action of the rammer 8,

sliding up and down upon the reinforcing bars 7, 7. Two sets of ties 13, 13 have been fitted around the reinforcing bars at sultable intervals apart and have been pressed into the fresh ballasting by the action of the 1rammel' 8 in order to maintain the bars 7, 7 at the correct distance apart.

Figure 7 shows the pile after it has been completely filled Wit-h ballasting, the ballastmg having been expanded to a suitable diameter into the loose soil 3 immediately above the solid rock 4 and tapering olf from that level to the base of the solidcla 2 through which clay the pile remains cy indrical. The casing tube 5 has been entirely removed from the bore hole.

Figure 8 shows the completed pile.I When the stage shown at Figure 7 is reached the four perforated pipes 7, 7Vare coupled up to a pumping or grouting plant and a mixture of cement and water or any suitable setting matter is forced to percolate from the perforated pipes 7a, 7a into the spaces between the gravel or ballast and from there into the fissures 17, 17 as also the pores or cavities of the surrounding strata.

It Will be clear that the minimum diameter to which the pile must expand at any given-level will vary with the total load to be supported by the pile, the nature of the strat-a at that level and the depth of the pile. It will also. be clear `that the original dia-meter of the bore hole,- the dimensions of the casing tube, the dimensions and weight of the rammel', the quantity of ballasting introduced at a time into the hole, the helght to which the .casing tube is lifted rammer for each load of fresh ballasting, as

also .the dimensions and number of the reinforcing bars are variable quantities which will be modified to suit different circumstances and conditions. The penetration oi the pile at its base into the solid rock 4 (when the solid rock is within economical i reach of the `bore hole) also effects a keying of the ile which prevents any tendency for-it to slide upon the surface of the rock when submitted to lateral strains and enables the-resistance of the pile to shearing stresses to come into action.

By meansof the present invention a more effective rooting or foundati'oning.r of the pile into'the ground is obtained owing .to the fact that the injection of the liquid cement or the like ensures a perfect-ly watertight joint between the. ballast which hnsbeen rammed into the hole and the sides of thev hole. The pile is also effectively rooted into the surrounding.ground owing to the fact that the cement or the like injected into the body of" the hole also flows and spreads into the adjacent fissures, channels und cavities in the surrounding ground thus forming a system of lateral supports which are more complicated and more substantially in proportion as the surrounding ground is more open and consequently more weak. The pile, therefore, is more stable, rigid and better supported:and-protected than with any previous known method of constructing piles, and owing to the spreadingl or lateral extensions ofthe pile into the surrounding ground the ground is Consolidated and strengthened to a substantial extent so that the effective area of supports given by the` 2. A method of forming a reinforced concrete pile which consists in forming a bore.

hole, fitting it with a temporary lining tube, vlocating a number of vertically disposed perforated steel tubes of suitable diameter therein, rammi-ng a mass of ballasting into .the ground and around the perforated tubes, lifting the casing during the ramming operation, 4and subsequently injecting a binding materia/'l through the perforated-tubes into the 'baila-sting as also into the surrounding strata.

3. A method of forming a reinforced concrete pile as claimed in claim l, in which ties are fitted duri-ng the operation of forcing the ballastin-g intoplace for the purpose of holding the perforated tubes at the correct i distances Aapa-rt.

' 4. A; method of "constructing concrete piles, lwhich consists in 'forming a bore hole, lfitting it with a temporary-lining tube, .locati/ng perforated tubes Withinthe bore hole,

ramrniing ballasting, into the ground and in the ground.

around `the perforated tubes by means of a cylindrical mass of metal which is free to slide along the perforated tubes so that the latter actas guides during its up and down movement, raisingthe lining tube and finally 'injecting liquid cement under pressure -through the perforated tubes into the mass of lballasting previously rammed in' place A method of constructing 'concrete piles, which consists 1n forming a bore hole,

fitting it with a ltemporary Elining tube, locating perforated ftubes inthe bore hole, placing ballasting, into the lining tubeand around the perforated tubes, expanding the said -ballasting, into the bore hole by ramming the. same While simultaneously raising the lining tube, andl finally injecting :i binding material under pressure through the perforated tubes into the mass of ballasting previously rammed in place in the ground.

6. A method of constructing concrete piles, which consists in forminga bore hole, fitting it with a temporary lining tube, ylocating perforated tubes in the bore hole, placing ballasting into the lining tube and around the perforated tubes, expanding the said ballasting into the bore hole by ramming the same While continuously raising the lining 'tube and finally injecting liquid cement under pressure through the perforat-A ed tubes into the mass of ballasting previously rammed in place in the ground.

'7. A method of forming a reinforced concrete pile which consists in forming a bore hole, fitting it with a temporary lining tube, locating a number of vertically disposed perforated steel tubes of suitable diameter therein, locating ballasting in the lining tube and around the perforated tubes, expanding the. said ballasting into the bore hole by ramming the same-and by continuously lift` ing the casing during the ramniing operation, and subsequently injecting a. binding material through the perforated VVtubes into the ballasting as also into the surrounding strata. t

8. A method of constructing concrete piles, which consists in fitting it With a temporary lining tube, locating perforated tubes within the bore hole, placing ballasting into the tube and around :the perfo-rated tubes, expanding the ballasting into the bore hole by ramming the same by means of acylindrical mass of metal Which is free to slideV along the perforated tubes so that the latter act as guides during its up and dow-n movement, continulously raising the .lining tube during the rammin-g action and finally. injecting liquid cement under pressure through the perforated tubes into the mass of ballasting previously rammed in place in the ground.

ABRAM RUPERT NEELA'NDS.

GEORGES DAMRY.

ming aA bore hole,-l

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