DE102018110487A1 - Deep foundation pile and method - Google Patents

Abstract

Disclosed is a deep foundation pile (1) with pile members (2) made of concrete, which are assembled one above the other in a longitudinal direction (3) and have a cavity (6) passing through in the longitudinal direction (3). Further, there is disclosed a deep-foundation method wherein a deep foundation pile (1) is produced by successively placing pile members (2) of concrete in a longitudinal direction (3) of the deep foundation pile (1) and pressing them into a ground (17), the pile members (2) 2) have a cavity (6) passing through in the longitudinal direction (3).
In order to improve the carrying capacity of a displacement pile, it is proposed that alternately first a steel core (20) closed at the lower end (13) with a cross-section of at least 150 cm ^{2 be} fed into the ground (17) and the pile members (2) tracked become

Description

The invention relates to a deep foundation pile with pile members made of concrete, which are joined together in a longitudinal direction and having a longitudinally continuous cavity. The invention further relates to a deep founding method wherein a deep foundation pile is produced by stacking concrete piles one after the other in a longitudinal direction of the deep foundation pile and pressing them into a ground, the pile members having a longitudinally continuous cavity.

Deep foundation piles are differentiated according to EA piles in bored piles and displacement piles: For a bored pile, a wellbore is prepared prior to or during manufacture by loosening soil volume and delivering it to the surface. Finally, the ground surrounding the deep foundation pile is solidified by injecting chemical binders, such as cement, through cavities in the deep foundation pile. Displacement piles, on the other hand, are pressed into the ground without prior excavation of soil material. While the load-bearing capacity of bored piles follows from their skin friction, displacement piles are pushed into the ground until a horizon that is demonstrably sustainable for a permanent peak load is reached.

A deep foundation pile and a deep foundation method with the features mentioned in the introduction are out US 8,272,810 B2 Known: In order to improve the alignment of the pile members of a Spülbohrpfahls one above the other there is proposed that guided by a cavity in the pile members segments of a guide tube with a diameter of 5/8 inch and are driven in turn with the pile members. Through the guide tube, a flushing liquid is pressed into the soil, which dissolves the surrounding soil volume and discharged to the surface, so that the pile members sink under their own weight or under slight pressure in the ground. Finally, the binder is injected through the guide tube into the ground.

task

The invention has for its object to improve the vertical load capacity of a displacement pile.

solution

Starting from the known deep foundation pile is proposed according to the invention that the deep foundation pile has a closed at the bottom, steel core with a cross section of at least 150 cm ² in the cavity. Such a steel core increases the vertical load capacity of the displacement pile and also avoids subsequent shifting of the pile members from the vertical axis by ground movements.

In a deep foundation pile according to the invention, preferably the core is a pipe and the pile members have a diameter between 30 and 50 cm and a height between 25 and 110 cm. Such a deep foundation pile according to the invention with a tubular core and / or pile members which can be handled manually in this way is particularly suitable for retrofitting under an existing structure in confined spaces.

In a deep foundation pile according to the invention, the pile members preferably have a symmetrical, preferably mirror-symmetrical and / or rotationally symmetrical cross-section transversely to the longitudinal direction. The symmetry simplifies the assembly of the pile members.

Preferably, in a deep foundation pile according to the invention, the pile members are tapered in the longitudinal direction with a slope between 2 and 10%. The slope is the difference between the radii at its two ends, relative to the length of a single pile member. The conical outer surfaces of the pile members transmit a higher proportion of the load into the surrounding soil than cylindrical pile members. The free through the different diameter ring surface between the individual pole links transmits in conically tapered pile members under stress on pressure in conically tapered pile members under train further load components into the ground. The conical shape of the pile members and the resulting heels in the pile surface also prevent a "floating" pile construction.

Preferably, a deep foundation pile according to the invention has steel inserts in the pile members and / or in the core. Such steel inserts increase the carrying capacity of the concrete structure.

Preferably, a deep foundation pile according to the invention has a tongue and groove joint centering juxtaposed pile members in the longitudinal direction against each other, more preferably the spring is formed by a pipe piece which engages in the cavity of the adjacent pile member. The centering ensures the static joining of the pile members.

Starting from the known method is proposed according to the invention that alternately first one at the bottom closed steel core with a cross-section of at least 150 cm ^{2 is} advanced into the ground and the pile members are tracked. The process according to the invention leads to one of the abovementioned press piles according to the invention and is initially distinguished equally by the advantages mentioned there. Due to the alternating advance of the pile members and the core, the respectively to be overcome resistance of the subsurface is significantly reduced and the deep foundation pile can be driven with the same pressing force into deeper soil layers. The carrying capacity of the deep foundation pile is thus further increased.

Preferably, in a method according to the invention, firstly a first core member of the core is pressed steadily into the ground, and further core members are placed successively on the first core member and likewise pressed steadily into the ground. Further preferably, the core members have a length between 60 and 150 cm. Such an inventive method with jointed core and / or such manually operable pile members is particularly suitable for retrofitting under an existing structure in tight spaces.

Preferably, in a method according to the invention, a cavity in the core is subsequently cast with concrete. The load-bearing capacity of the core and thus also of the deep foundation pile is thus further increased.

embodiments

The invention will be explained below with reference to exemplary embodiments. The drawing figure shows a lower segment of a first deep foundation pile according to the invention 1 , The segment shown consists of three prefabricated pile members 2 that is only at the construction site in a longitudinal direction 3 of the deep foundation pile 1 with tubular core members 4 . 5 to the deep foundation pile 1 be joined together. One in the stakes 2 in the longitudinal direction 3 continuous cavity 6 is from the core links 4 . 5 filled.

The pile members 2 consist of reinforced concrete, have a height 7 of 40 cm, a circular cross-section with a head diameter 8th of 40 cm and one foot diameter 9 of 36 cm and thus an inclination of 5.45%. The steel inserts of the pile members, not shown 2 are designed as spiral reinforcement and compensate for resulting transverse and splitting tensile forces.

The cavity 6 has a free diameter 10 of 15 cm and thus a cross section of 177 cm ² , the first core member 4 a length 11 of 100 cm and every other core link 5 a length 12 from 80 cm up. The first core member 4 is at its lower end 13 closed.

The lateral surfaces 14 the pile members 2 are conical towards the longitudinal direction 3 inclined, so that at the respective union always a jump 15 between head diameter 8th and foot diameter 9 is available. The deep foundation pile 1 has a scale-like gradation.

The deep foundation pile 1 is prepared as a displacement pile, so without preparing before or during manufacture by loosening and conveying off soil volume a hole: First, a first pile member 2 on the surface 16 set and the first core member 4 through the cavity 6 hydraulically in the under surface 16 reason 17 propelled. Then another core link 5 on the first core member 4 put on and welded with this. The core links 4 . 5 show at the top 18 a welded steel ring 19 on, the following core element 5 in the longitudinal direction 3 centered.

Subsequently, another stake element 2 put on and hydraulically in the ground 17 propelled. Further core links 5 and pole links 2 are alternately placed and hydraulically propelled until the deep foundation pile 1 has the desired carrying capacity. The carrying capacity of the deep foundation pile 1 is the sum of the at the topmost pile member 2 and the topmost core member 5 demonstrable carrying capacities. Finally, the core members 4 . 5 (not shown) monolithically poured with concrete to the core formed from it 20 mechanically stabilize.

In other embodiments, not shown, depending on the requirements of the substrate and the structure of the cross section of the pile members 2 matched to the desired load capacity. The cross section may alternatively be polygonal. The inclination is between 2 and 10% on the ground conditions, the height 7 the pile members 2 between 25 and 110 cm, the diameter 9 of the cavity 5 above 12 cm and the length 11 . 12 the core links 4 . 5 between 60 and 150 cm adapted to transport, safety and installation conditions. The pile members 2 are calculated and constructed in accordance with DIN 1045.

The Tiefgründungspfahle invention have a relation to the prior art significantly increased resilience on skin friction resistance, in coordination with the locally explored soil conditions and allow safe planning of Pfahleinbaus, in coordination with the locally explored soil conditions in the ground, even on tensile stress.

LIST OF REFERENCE NUMBERS

1

Deep foundation pile (segment)

2

pile element

3

longitudinal direction

4

first core member

5

another core member

6

cavity

7

height

8th

Head diameter

9

Base diameter

10

diameter

11

length

12

length

13

lower end

14

lateral surface

15

Leaps

16

surface

17

reason

18

top end

19

steel ring

20

core

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 8272810 B2 [0003]

Claims (10)

Deep foundation pile (1) with pile members (2) made of concrete, which are joined together in a longitudinal direction (3) and have a cavity (6) passing through in the longitudinal direction (3), characterized by a steel core closed at the lower end (13) (20) with a cross section of at least 150 cm ² in the cavity (6). Deep foundation pile (1) according to the preceding claim, characterized in that the core (20) is a pipe. Deep foundation pile (1) according to one of the preceding claims, characterized in that the pile members (2) have a diameter between 30 and 50 cm. Deep foundation pile (1) according to one of the preceding claims, characterized in that the pile members (2) have a height (7) between 25 and 110 cm. Deep foundation pile (1) according to one of the preceding claims, characterized in that the pile members (2) transversely to the longitudinal direction (3) have a symmetrical, preferably mirror and / or rotationally symmetrical cross section. Deep foundation pile (1) according to any one of the preceding claims, characterized in that the pile members (2) taper in the longitudinal direction (3) with an inclination between 2 and 10%. Deep foundation method wherein a deep foundation pile (1) is prepared by successively placing pile members (2) of concrete in a longitudinal direction (3) of the deep foundation pile (1) and pressing them into a ground (17), the pile members (2) having an in Having the longitudinal direction (3) through cavity (6), characterized in that initially at the lower end (13) closed, steel core (20) is advanced with a cross section of at least 150 cm ² in the ground (17) and the pile members (2) be tracked. Deep foundation method according to the preceding claim, characterized in that firstly a first core member (4) of the core (20) is pressed steadily into the bottom (17) and further core members (5) successively placed on the first core member (4) and also steadily in the bottom (17) to be pressed. Deep foundation method according to the preceding claim, characterized in that the core members (4, 5) have a length between 60 and 150 cm. Deep founding method according to one of Claims 7 to 9 , characterized in that a cavity (6) in the core (20) is subsequently cast with concrete.

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