A JOINT OF AND AN EXTENSION MEMBER OF A SHAFT OF A PILE OR EARTH ANCHOR

Abstract: A shaft of a pile or earth anchor comprises extension members that are added as the shaft is forced into the ground. The joints are held together by tongues (22, 23; 14, 15; 33, 34) that are welded to the forward end of each extension member and bent rearwardly around holds (24, 25; 16, 17; 35, 36) on the rear end of the preceding extension member.

Description: A joint of and an extension member of a shaft of a pile or earth anchor. This invention relates to a joint of a tubular shaft on a pile or earth anchor, in which one end of an extension member of the shaft has a sleeve into which or onto which another extension member can be mounted. The invention relates also to an extension member for a shaft of a pile or earth anchor. Shafts of this kind can be used for example for expansion bodies at the kind that are described in EP-A 0079875 and EP-A 0112316. The bodies are expanded by cement grout that is forced through the shaft. For preventing leakage and for preventing separation of the joints, the joints are usually welded on site, which is expensive and time consuming. According the invention an inexpensive joint is provided which does not separate and which is sufficiently tight and makes the installation fast. The invention will be described with reference to the accompaning drawings: Fig 1 shows, in a longitudinal view, a joint being made. Fig 2 shows, in a longitudinal view, a completed joint. Fig 3 is a section taken along the line 3-3 in Fig. 1. Fig 4 is a section taken along the line 4-4 in Fig. 2. Figs 5 and 6 show in longitudinal views two alternative embodiments of a joint. Figs 1 and 2 are to be seen together as is indicated by the dash-and-dot center line. The reference number 11 refers to an extension member of a shaft of a non-illustrated expansion body, the expansion body and the expansion member 11 being forced into the ground, that is, to the left in Fig. 2. An extension member 12 that has been added to the extension member 11 has also been forced into the ground so that only its upper end shown in Fig 1 is above ground. The extension members 11, 12 are held together by means of a jointing sleeve 13, that is attached to the extension member 12 by being welded to it. The jointing sleeve 13 has two arresting strips or tongues 14, 15 that are attached to the jointing sleeve by being welded to it and the extension member 11 has two holds 16, 17 through which the arresting strips have been moved and bent rearwardly. The arresting strips are held bent rearwardly by the ground and, thus they hold together the jointing- sleeve 12, that is welded to the extension member 12, and the extension member 11. In Fig 1 is illustrated the addition of an extension member 20 on the end of the extension member 12 that projects out of the ground. This extension member 20 has also a jointing sleeve 21 welded to it. The sleeve has two forward directed arresting strips 22, 23 that have been moved through holds 24, 25 on the extension member 12. Between the jointing sleeve 21, that is a part of the extension member 20, and the extension member 12, there can suitably be a press fit so that the joint is only completed when the upper end of the extension member is hit, that is, when the driving in of the expansion body is restarted. The pile or anchor is usually hammered down into the earth by a hammer that hits the near end of the shaft. The operator could advantageously bend the arresting strips 22, 23, backwards but they will be bent backwardly when they reach the ground also if the operator did not bend them. As appears from the above discription, the pile shaft is made up by extension members that, as can be seen on the extension member 12, has a jointing sleeve 13 with arresting strips on its front end and holds 24, 25 for the arresting strips on its rear end. If the shaft is part of an earth anchor, reinforcing rods can be lowered into the tubular shaft so that they will be embedded in cement grout when the anchor is expanded and the tubular shaft itself need not take up any pull. It is important only that the shaft does not separate during the installation and during the injection of grout which usually needs a pressure of 10-20 Pa. The mounting of the bottom part of the shaft on the expansion body, that is on the foot of the pile or anchor, is not illustrated but reference is made to the above mentioned patent specifications. In Fig 5, an alternative embodiment is shown in which a rear extension member 30 has been added to a forward extension member 31. The jointing sleeve 32 is fixed internally in the extension member 30 by welding dots and the arresting strips 33, 34 are welded to the extension member 30 and moved through holds 35, 36 in the forward expansion member 31. In Fig 6, a modified form of the joint shown in Fig 5 is shown. The jointing sleeve 32 has a centrally located flange 37 that transmits the driving force from the rear extension member 30 to the forward extension member 31. Thus, the jointing sleeve 32 is held in place by the flange 37 and it need not be welded to one of the extension members.

Claims: Claims 1. A joint of a tubular shaft (11, 12, 20; 30, 31) of a pile. or. earth anchor, in which one end of an extension member of the shaft has a sleeve (21, 22) into which or onto which one end of another extension member can be mounted, c h a r a c t e r i z e d in that the extension member (20) that is added as an extension of the shaft has at least one arresting tongue (22, 23; 33, 34) that extends forwardly and the other- extension member (12, 31) has a hold (24, 25; 35-, 3.6) for: t e; tongue around which the tongue can be bent rearwardly. 2. A joint according to claim 1, c h a r a c t e r i z e d in that the sleeve (21) is fixedly arranged on the rear extension member (20) and the arresting tongue (22, 23) is fixedly arranged on the sleeve. 3. A joint according to claim 1 or 2, c h a r a c t e r i z e d in that the sleeve (21) and the arresting tongue (22, 23) are fixed by welding. 4. A joint according to any one of the preceeding claims, c h a r a c t e r i z e d in that the extension members (20, 12; 30, 31) are of steel and the sleeve (21, 32) has a press fit to the extension member (12, 31) onto which or into which it is to be forced. 5. An extension member for a shaft of a pile or earth anchor, comprising a tube (12, 13) c h a r a c t e r i z e d by at least one arresting tongue (14, 15) at one end, the tongue being affixed at its rear and and extending forewardly in the driving direction, and at least one hold (24, 25) at the other end of the extension member around which a corresponding tongue of another extension member can be bent.

Inventors: SKOGBERG BO TORBJOERN, SKOGBERG, BO, TORBJOERN
Applicants: SKOGBERG BO T, SKOGBERG, BO, TORBJOERN
Application year: 1987
Main classification: E02D5
IPC codes: E02D5