Sheet metal piling

Application filed June 19, 1928, Serial No.

This invention relates to coffer-dam constructions and aims to provide an improved wall structure formed by sections of sheet metal piling.

It is universally known that the building of ships of increased drafts necessitates the deepening of harbors. To accomplish this, existing quay ways must be strengthened or else re-built so as to withstand the stresses placed upon them. Sheet metal piling is generally conceded to be the most suitable material for the purpose and also for replacing the comparatively more expensive pile foundations. Nevertheless, the sheet piling constructions heretofore known are incapable of meeting the latest requirements. Most of those now in use are built with sections of channel or other form, the moments of resistance of which cannot be sufficiently increased or improved, so that further development of sheet piling according to 1-° test requirements calls for new structural forms.

The only type of section found to be suitable as the basis of these structural forms is the I section, which alone is able to provide the maximum moments of resistance. Moreover, the material is most economically utilized in this type of section. A number of different constructions embodying I sections ³⁰ are knoAvn but none of them meets present day requirements for the following reasons, viz:

1. Where solid walls are composed of said type of sections, the conditions under which ³⁵ anchoring means must be attached are unfavorable because the central webs of the sections interfere while their flanges are considerably weakened by the passage of heavy anchoring members therethrough..

⁴⁰ 2. Under ramming blows, all sheet piling splays in the direction of the wall axis and accordingly gets out of the perpendicular so that provision must be made to counteract the ramming effect. This is done in the case ⁴⁵ of channel sections for example, by hammering or pressing out some of the pile members into tapered form and inserting the same at definite intervals, so as to bring the next pile member to the perpendicular. In ⁵⁰ the ca-e of I sections however, where the

286,689, and in Germany June 20, 1927.

central webs are at right angles to the wall axis, this corrective expedient cannot be utilized since the sections cannot be tapered.

3. It is necessary for the walls to be free of projections, so that ladders or the like 55 must be countersunk or recessed into the walls, which is impracticable when they are constructed solely of I sections, unless special and expensive constructional forms are additionally used. ⁶⁰

4. In order to produce efficient and satisfactory piling avails, it is necessary insofar as possible to eliminate excess hydrostatic pressures causing rearward filling, but this cannot be accomplished with Avails con- 65 structed solely of I sections without reducing their moment of resistance.

From the foregoing it will be apparent that the problem to be solved resides in the construction of a sheet piling which consists 7(1 mainly of sections having webs disposed, at right angles to the axis of the Avail, and Avhich in combination with a high moment of resistance will have the added advantages of (1) enabling easy attachment of the anchor- 75 ing means; (2) permitting the effect of ramming to be easily counteracted; (3) permitting arrangements of auxiliary constructions such as ladders to be made in countersunk or recessed relation to the main front or sur- 80 face of the structure; and (4) providing simple structural means for excluding excess hydrostatic pressures.

The present invention solves the aforesaid problem by providing a structure in Avhich 85 I sections are alternated, either singly or in groups of tAvo or more, with sections which are open toward the face of the wall, such for example as channel sections or H sections with the central Aveb running parallel 9® to the Avail axis. In such structure, the I sections, whether alternated singly or in groups of a plurality, give strength and greatly increased moment of resistance to the Avail, while the interposed channel or H sections 95 serve to counteract the result of ramming and for the attachment of recessed auxiliary structures or members besides providing for easy attachment of the anchoring means and for the exclusion or reduction of excess hydro- 10®

1,835,367 static pressures. This construction has the still f urther advantage of reducing the weight per unit area of the wall since the interposed channel or H sections occupy spaces along g the walls somewhat wider than the respective I sections.

The invention will be best understood by further description with reference to the attached dniw’ngs showing two practical em₁₀ bodiments thereof in a coffer-dam wall structure.

In said drawings:

Fig. 1 is a sectional plan view of one form <>f wall structure; and ,g Fig. 2 is a similar view of another form of wall structure.

The walls of the illustrative structures are. shown formed by metal piling sections a of I-shape connected together with their cen20 tral webs disposed at right angles to the wall axis. In this instance the sections are connected together by T-shape members or bars d Complementarity fitting between flanges of adjacent sections along their edges, but any 2g other suitable joining means may be used or the sections may be interfitted directly in complementary joints as may be preferred, the manner of connecting the individual sections being relatively immaterial. These sec30 tions compose the basic structural members of the Avail and by virtue of their form impart thereto the necessary moment of resistance.

At predetermined intervals along the wall are interposed trough-like sections having 35 their central portions or Avebs extending in the axial direction of the wall or running substantially parallel therewith. These last mentioned sections may be in the form of channel members b as shown in Fig. 1, or in 40 the form of H-shaped members c as shown in Fig. 2. They are shown fitting complementarity with the flange portions of the I sectiors between which they are interposed as unitary parts of the wall, but may otherwise 45 be connected in place by substantially watertight joints. These sections b or c are interposed or connected preferably between · groups of two or more of the I sections, but if desired,, may be alternated with single of 50 these sections. In the present instance the I sections are represented in groups of three but according to requirements in actual constructions there may be less or more in any group and the greater the number in each of 55 the groups the greater will be the resistive moment of the wall.

These trough-like sections b and c may be tapered by splaying or compressing so as to restore the 'perpendicular relation or aline60 ment of the I sections at points where interposed in the wall so as to counteract the effects of ramming as hereinbefore stated. They thus serve as corrective members in the wall structure. They also serve to particular ⁸³ advantage for attachment of the necessary anchoring means, as obviously heavy shafts or bars may be extended through and bolted to them more easily than the I sections. Such anchorage attachment moreover will avoid weakening the wall as unavoidably results 7° from attachment to any I section. By reason of the fact that these trough-like sections in effect recede into the wall, they afford the possibility of accommodating recessed aux_?. , iliary appliances, such as ladders, fire hose, 75 mooring devices, etc. Their interposition at intervals between groups of the I sections has the still further advantage of reducing the weight of the wall per unit area.

A greatly improved wall piling is thus ⁸⁰produced in which the advantages of I-shape sections with those of channel or trough-like sections are combined in a less costly and more perfect structure of greatly increased strength and resistance moment with a re- ⁸⁸duction of weight per unit of wall area.