US2164003A - Method of building subterranean structures - Google Patents

Description

June 27, 1939. H. scHEELHAAsE AMETHOD OF BUILDING SUBTERRANEAN STRUCTURES Filed March 31, 1937 4 Sheets-Sheet 1 June 27, 1939.

H. SCHEELHAASE METHOD OF BUILDING SUBTERRANEAN STRUCTURES Filed March 3l, 1937 4 Sheets-Shea*I 2 ffy. 9

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ZEN? k June 27, 1939. H. scHEELHAAsE METHOD OF BUILDING SUBTERRANEAN STRUCTURES Filed March 3l, 1937 4 Sheets-Sheet 5 miams-x nl Y Immun um,

June 27, 1939- H. scHELHAAsE 2,164,003

METHOD OF BUILDING SUBTERRANEAN STRUCTURES- Filed Mzlarch 5l, 1937 4 Shets-Sheet 4 Patented June 27, 1939 STRUCTURE Hermann Scheelhaase, Fallersleben, Germany Application March 31, 1937, Serial No. 134,032

- In Germany July 18, 1934 6 Claims.

This invention relates to methods for the production of structures in the ground water or in the open water. It is intended to principally simplify the excavation of trenches or pits and 5 reduce the necessary ballasting and the concrete mass of the bed.

For laying the foundations for structures such as siphons, culverts, conduits, quay walls and structural foundations in general, it is known to l excavate trenches, the walls of which are formed by sheet piling and which are shut-off at the bottom 'by a reinforced concrete bed produced under water. The tending of the bed to rise can be counteracted by employing a suitable concrete l -mass, or separate ballasting materials may be appli'd to the bed. As the trench or pit should always be kept free from ballasting materials these were arranged either under the bed proper 'or the concrete bed was weighted by lateral' 2o ballasting so that the size of the trench or pit was determined by the size of the structural parts and the ballasting materials aranged at both sides. 'Ihis resulted in a dividing of the trench, in that the lateral ballasting materials g5 were in turn enclosed by separately built walls Jwithin which `the structure proper had'to be erected. This arrangement resulted in the bedbelng wider than the size of the structure, and consequently more excavation work was required 30 and larger quantities of concrete were necessary. It is also known, for example in the building of tunnels, to build the tunnel roof on or between pit trench walls, the ground water being lowered at the same time. 35 roof, the two trench walls and the trench bottom is then removed in a dry state, by working from one or both ends of the tunnel. The main disadvantage of this method and also of many other methods, is the necessity of lowering the ground u vWater which is extremely unfavourable not only from an economical but also frorna .technical point of view. The ground water must be maintained in a lowered state during practically the whole time the tunnel is being built. The suc- 45 cess of such a building method is therefore entirely dependent upon the perfect operation of the ground water lowering plant. If from any cause (machine defect, failure of current, frost or the like) any interruption of protracted dura- 50 tion occurs in connection with the lowering of the The earth between the tunnel (Cl. lil-46) important disadvantage, namely that the strata situated within thev area in which the ground water is lowered shrink owing to the extraction of the water. These shrinkages often cause considerable damage to neighbouring buildings and other structures, and even endanger the pits or trenches themselves.

The invention is based on the idea that, for the purposes of obtaining a considerable saving in work and materials, it is necessary to determine the size of the trench or pit and thewmass of the concrete bed plate only according to the size of the structure to be built and not to employ for the ballasting separate spaces laterally of the structural parts. Furthermore, the ground 16 water remains undisturbed during the entire building period. The problem is solved by spreading directly over the entire width of the bed plate which corresponds to the size of the structure, the necessary baliasting materials to prezo vent rising of the bed plate. After the filled in ballast earth has been pumped dry, the trench is divided by a partition and half the trench is cleared between the middle and the outer sheet piling, in which half of the structure is built in the dry trench. When the one half is finished, the ballasting earth can be transferred from the unfinished side to the finished side, the trench being at the same time progressively stifiened;

the earth remains in this position as filling-in earth. 'I'he other half of the structure can then be constructed.

'I'he advantages of the method do not consist solely in the reduction of the size of the pit or trench which need only be excavated to 'a width 35 necessary for the structure itself, but also in that the bed plate, preferably constructed as truss support, is xed in a certain sense at one side, while one half of the structure is completed. The iron work is then placed on the undersides of the 40 plate so that it is possible to continuously concrete without interruptions due to the iron work,

a good development of the reinforcement with concrete being positively ensured. In the case of reinforcing iron work lying at the top, it is diiilcult to reliably lay the under water concrete and also only in short sections. In the case of lateral ballasting under certain circumstances the inner walls ought to be erected under water, which necessitates expensive under water work; this work is omitted in the method according to the invention. Finally the pump lines reaching to the bed can easily lead off any water entering owing to leakages in the sheet piling joints.

Several embodiments of thel invention are ilf middle of the structure illustrated in Fig. 1 showing different stages of work.

Figs. 9 to 16 are cross sections showing different stages inthe building of a tunnel under a river bed.

Figs. 16 to 20 are cross sections showing different stages in the building of a tunnel of a modified shape under a river bed.

Figs. 21 and 23 are longitudinal sections of a bridge pier in a river showing the different steps inthe construction thereof.

Fig. 22 is a sectional view taken on line I-I of Fig. 21.

In Fig. 1 the foundation is designated by I, the concrete bed by 2, a siphon pipe by 3, whereas the filling of the trench is designated by 4 and the stone packing above the sand filling is designated by 5.

First the trench (Fig. 2) corresponding to the diameter of the pipe or pipes plus the pipe clearance, when several pipes are laid, is excavated and lined with iron sheet pilings 6, 1. The rst working stage is the ramming by applying blows to the pilings G and 1. After ramming in the sheet pilings, the trench is excavated by means of an excavator without drainage. The top portion of the pilings i and 1 may be braced by struts l.

Round iron rods 9, preferably plaited into continuous mats, are then lowered into the trench after the bed has been accurately levelled. The

iron mats may be suspended on the upper edge of the sheet piling by means of auxiliary erection irons. 'I'he portions 2', 2" and so forth of the base rise from the middle at an incline of 1:4, and must be interrupted. With this object in view 4sheet iron plates I0, III and so forth reinforced with section irons are provided.

When the whole of the iron reinforcement has A been fitted the laying of the cement is commenced without altering the ground water level, which can be carried out without hindrance owing to the iron reinforcements.

Pipes II, I2 (Fig. 3) are fitted on the sheet piling walls and loading gravel I5 and ballastlng material I3 is then added to the calculated height and quantity by weight (Fig. 4), whereupon the water is pumped out of the trench by means of the pipes II and I2. The ground water level outside the sheet piling wall remains uninfluenced.

When the whole of the gravel and sand lling has been pumped dry a middle sheet piling wall I4 with extended guide post is rammed in so that one side-of the trench can be again excavated down to the ballasting gravel I5 which imparts the necessary hold for the middle sheet pilinfr wall I4. A suitable shoring IG, I1 of the trench is carried `out so that the slphonpipes of the one side can be laid.

When one half of the structure has been completed the ballasting material is transferred from the non-finished to the finished side (Fig. 7) and remains there as filling bottom. The second half of the structure such as a pipe 3a can then be completed with the aid of shorings I8, Il and 2l, whereupon, after the drawing of the iron sheet piling walls and removal of the pipes II and I2 and covering of the sand filling I3 with storie packing s, the building work is finished.

Figs. 9 to 15 show the building of a tunnel under a river bed.

The trench walls 22, on which bracket pieces 23 and if desired also suitably shaped gusset plates 24 are xed, are rammed sufllciently deeply into the bed. The earth of the river'bed 25, between the two sheet piling walls 22 is excavated and the reinforced concrete bed 21 of the tunnel is laid under water according to any of the known methods. 'I'he suction pipe conduits 28 are then fitted.

The thickness a of the reinforced concrete bed 21 is such that it is capable of taking up the l forces normally acting in a tunnel structure, or the dead load, live load, earth pressure and water pressure. The weight of the concrete bed 21 under these conditions is, however, in thefinajority of cases not heavy enough to oifer enough resistance to the rising forces acting on the concrete bed 21, when the trench is pumped dry. Consequently in such cases a layer 23 of sand or similar material is according to the invention added on the concrete bed 21. 'Ihe trench is thenpumped dry by pumps connected to the suction pipes 23, as far as the building of the roof requires. 'I'he thickness i of the sand layer 29 must be at leastso great that the total weight of the concrete bed 21 and of the sand layer 29 with the water contained therein and possibly the wall friction with the sheet piling walls is equal to or greater than the upward pressure acting on the underside of the concrete bed 21.

The reinforced concrete root 30 is completed on the sand layer 29. 'Ihe ends of the concrete roof 30 rest on the bracket pieces 23. Horizontal ribs 3I are then fitted on the sheet piling walls 22 above the concrete roof 30. These ribs bind in a packing layer 32 of clay or similar material. A ballast layer 33 is then applied on the clay layer 32 for protecting the same. When the ballast layer 33 has been laid the sheet piling walls 22 are cut olf at the height of the river bed 25. Consequently the tratlic will not be impeded during the further work.

Fig. 12 shows the portion A of Fig. ll on an enlarged scale.

vThe partitions and shoring of working spaces 34 is commenced from one or both ends of the tunnel, for the encasing and concreting of the side walls 35. It must be ascertained whether the upward pressure conditions allow formation of the working spaces 34 at the same time on both sides of the cross section (Fig. 14), or only on one side as shown in Fig. 13. It is possible to arrange the shoring walls 36 in an earlier working stage, for example before or after the application of the sand layer 29. When the concrete of the side walls 35 has hardened in the prescribed manner, the shoring Walls 36 and the still remaining sand core 29 can be removed, the building of the tunnel being then finished.

It is likewise possible, to remove the sand iling in mining fashion after the finishing of the roof and removal of the water, for example as shown in cross section in Fig. l5, this being carried out from one end or from both ends of the tunnel. `It is advisable, as indicated in the drawing, to x props 31 between bed and roof in accordance with the advancing of the work and to leave them in position until the side walls are finished.

If the clearance between the upper edge of the bed plate and the lower edge of the roof will root finished thereon.

yanimos allow, a water illllng alone may suillce as ballast. In this instance a `suitable Ialsework scaifolding is erected on the bed plate from above and the When the sheet piling wall has been cut oft in the river bed, the ballast water removed, the side wallsare ilnished and the falsework scaffolding isdlsmantled.

Figs. 16 to 20 show aslightly modified arrangement for building a subaqueous tunnel.

In these iigures the buliding ground is shown by 4I, the side sheet piling walls by 4I and the concrete bed by 42. i i

Afterthe sheet piling irons have been rammed in, the earth is excavated and the concrete or reinforced concrete bed is laid under water in a known manner. When the suction pipes 43 have been fitted, the trench is filled with ballast material' 44 (sand, grvel or the like) to the desired height, so as to weight the bed against upward pressure, and pumped dry. A working space can now be produced which at the same time corresponds to the final internal section of the tunnel,

by driving sheet piling walls 45 into the filling,

applying the roof 30a with a protecting layer 33a,

. and cutting oil the projecting sheets 4I,V so'that Where conditions will allow, it is possible. to proceed in the manner shown in Figs. 16 to 20.

According to Fig. 16 the sheet piling walls 4l are first rammed and the bed 42 laid under water. The suction pipes 43 are fitted for pumping the trench dry. Ballast 44 is laid on the bed as shown in Fig. 17 and, after the trench has been pumped dry, working rooms 46 and 41 are partitioned oil with the aid of Walls 45 and emptied as shown in Fig. 18; whereupon the side walls at the right and left are completed. After the partitions have been drawn the concrete roof 30a and the protecting layer 33a thereon can be laid in the dry, the filling material still existing being again illed with water if necessary. The space still remaining free can be filled with water almost up to the lower edge of the roof, so as to produce additional ballast. Finally the outer sheet piling walls 4I are cut oif and the waterv and the earth core removed.

`By simultaneously building the working spaces I8 and4'l not only can the-work progress much more rapidly but an absolutely symmetrical vloading of the ground under the bed during all stages of construction is attained; furthermore the ballasting material enclosed by the side walls is entirely unaifected. Thus very considerable advantages are obtained as compared with the method according to Figs. 1 to 8. y

Another mode of execution for laying a bridge pier is shown in Figs. 2l to 23. When the trench or pit has been partitioned on by sheet pilings and a reinforced concrete bed 42 has been laid the pump pipes 43 are fitted after the necessary excavation under water. Partitions 48, which in this instance consist of separate reinforced concrete beams, are erected under water transversely to the longitudinal direction of the pier. These beams are well guided in lateral directions in the corrugations of the corrugated sheet piling walls `4la and at the same time participate to a certain extent in the shoring. As soon as the partitions are suiliciently high, the space enclosed by the partitions and the side walls of the trench or pit arefilled with ballast 60 which may consist of poor concrete. When the hole has been pumped dry by means of the pipes 43 the'pier il is concreted. By suitably constructing the partitions it may be sumclent to pump out only the side chambers.

By this method of laying a foundation it is possible, contrary to the methods hitherto generally employed, to make the parts which are situated under the points of support of the bridge and which are consequently subjected to particularlyheavy stresses, of particularly high grade cement. `Furthermore the packing material and also the partitions remain in the structure as permanent part thereof. The advantage as compared with the usual methods of building foundations by means of caissons are evident.

It is evident that it is not always necessary to subdivide the working space `to the full height. It may even be advisable,`to arrange the partition walls for partitioning oi the ballast chambers both in longitudinal direction and also in a transverse direction (that isin both the main axes of the structure). In this instance it is preferable to provide for example in the transverse partitions welts for slipping in the longitudinal partitions. It is likewise not necessary to bring in the filling material in such quantity that it alone opposes the upward pressure since a portion of the ballast can be replaced by water depending upon the nature of -the structure and other circumstances. Furthermore it is possible, if the concrete Walls or piles rising from the bed plate are produced in subaqueous cast concrete, to introduce the ballast at the same time as the concrete.

The method according to the invention can also be applied in the same sense for rebuilding work.

I claim:

1. The method of forming an opening in the ground which contains sufficient water to exert a buoyant pressure in which opening construction work may be manually performed which comprises, driving sheet pilings into the ground to provide side walls for the opening, removing the solid matter between the side walls-without removing the water, constructing a concrete bed plate to extend between the sheet pilings so as to provide a sealed bottom for the opening, depositing ballasting material into the opening so as to rest on the bed plate in a quantity to provide sufiicient weight to resist upward movement of the bed plate in the absence of Water in the opening, removing the water from the opening, and thereafter conning the ballast material to a portion of the bed plate so that a space will be provided for manual Work to be performed in the space.

2.The method of forming a trench in the ground in the presence of water wherein construction Work may be manually performed which comprises, ramrning sheet pilings into the ground in a spaced relation to provide side walls for the trench, evacuating the solid matter between the side walls without removing the water, constructing a reinforced concrete bed plate in the bottom of the trench so as to seal the space between the side walls, depositing ballasting material into the trench onto the bed plate, removing the water from the trench with the ballast material remaining therein which resists upward movement of the bed plate, and thereafter moving the ballast material laterally in the trench to provide a work space whereby sufcient weight is maintained on the bed plate to prevent buckling thereof while work\is performed in the trench.

3. The method of forming a trench ln the ground in the presence of water wherein construction work may be manually performed which comprises, ramming sheet pilings into the ground in a spaced relation to provide side walls for the trench. evacuating the, solid matter between the side walls without removing the water,-

constructing a reinforced concrete bed plate in the bottom of the trench so as to seal the space between the side walls, depositing ballasting material into the trench onto the bed plate, re-f` moving the water from the trench with the bal-r last material remaining therein which resists upward movement of the bed plate, driving a sheet piling into the ballast material so as to provide an intermediate wall in the trench, moving a portion of the ballast material from one side of the last mentioned sheet piling to the other side l thereof so as to provide a work space in the water out ofthe trench. forming working spaces by moving the ballasting material laterally in which the structure is then-erected.

5. A method for the production of structures with the aid of a trench in which the structure is erected in ground. water or in open water consisting in, driving in sheet pilings to crib the trench. removing the earth between the sheet Y pilings. producing a reinforced concrete plate las a trench bottom seal between the sheet pilings.

lowering spaced partitions under water into the trench between the sheet piling. introducing ballasting material in the space between' partitions, pumping the water out of the trench and then erectingthe structure in the-free spaces.

8.*Amethod i'orv the production oi' structures with thel aid of an opening in which the structure is erected in ground water or in open water consistingin. ramming sheet pilings to crib the opening. removing the earth between the sheet pilings, producing a reinforced concrete plate as a trench bottom seal between the sheet pilings, introducing a sumcient quantity of the ballasting material onto the bed plate for resisting the buoyancy acting thereon, pumping the water out of the trench, ramming a sheet piling into the ballasting material and moving the ballasting material from one side of the last mentioned piling to the other side thereof so that the structure may be erected in the free space.

HERMANN BCE.

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