This invention relates to emplacement of foraminous piping in non-cohesive subsoils, as for subsoil fluidization by flow of water thereinto from such piping, or for subsoil dewatering by flow of water out therefrom into such piping, especially ways and means for burying such piping therein.

BACKGROUND OF THE INVENTION

Numerous methods have been suggested and many have been used in efforts to control coastal erosion and deposition of subsoil, such as by encouraging accretion of sand and other non-cohesive subsoils in the instance of beaches, and to dis- courage deposition of (or to remove) undesired sand or soil, especially when deposited in harbors and navigable channels. Efforts to overcome ^■ undesired effects of wave action have usually been unavailing in the long run, sometimes producing the opposite of what was sought and/or other deleterious results. Man has had to learn to use nature rather than to fight it in such environmental efforts.

Channel maintenance (or creation) traditionally is ac¬ complished by dredging, repeated whenever currents or wave action fill in the channel, usually frequently. Dredging costs enough the first time, and necessary repetition is an aggravation of expense. Fluidization as an alternative to dredging is also well recognized, having been noted as long as a century ago by Scott in U.S. Patent 510,713. Also known in the nineteenth century was bypassing of sand, whether from a natural or an induced deposit, as in O'Meara U.S. Pat. 593,430, to a more desirable location, as by pump¬ ing to a means of transport or more directly thereto.

Beach subsoil dewatering is more of a twentieth century development. Informative articles include such as "New Method for Beach Erosion Control" by Machemehl, French, and Huang in Civil Engineering in the Oceans/III (1975) pp. 142- 160 and "Experimental Control of Beach Face Dynamics by ater-Table Pumping" by Chappell, Eliot, Bradshaw, and Lonsdale in Engineering Geology, 14 (1979) pp. 21-40.

Both of the latter published articles describe how water withdrawal from subjacent beach sand is conducive to deposi¬ tion of more sand. Vesterby U.S. Patent 4,645,377 teaches such dewatering—just below the mean high water level. All such methods utilize piping buried in one way or another, and even fluidization as an alternative channel clearing and maintenance method has relied upon the energy-intensive step of dredging to enable the necessary piping to be buried.

The pipe placement art is represented by van Steveninck as in U.S. Patent 3,695,049, in which piping to be buried is supplied with one or more accompanying pipes to fluidize un¬ derlying subsoil "causing the pipeline together with the fluidization pipes to sink into the fluidized seabed" -and as in "Pipeline Burial by Fluidization" Paper No. OTC 2276 of OFFSHORE TECHNOLOGY CONFERENCE of the American Institute of Mining, Metallurgical, and Petroleum Engineers at Dallas, Texas in 1975, wherein a horseshoe-shaped device overlies and straddles piping to be emplaced and fluidizes the ad¬ jacent non-cohesive bottom with water jetted from openings in hollow lower stringers of such device. The piping sags under its weight and the extra weight of any straddling device and sinks into the adjacent fluidized bottom of the subjacent soil, preferably sandy—as clay may interfere.

SUMMARY OF THE INVENTION

My present invention provides improved means and methods for burying and using such piping in subsoil that is non-cohesive when wet, such as for fluidization of adjacent subsoil, as for navigable channel or harbor maintenance, or for dewatering adjacent subsoil, as for beach maintenance.

In general, the inventive method comprises the steps of positioning foraminous piping along a desired route on such non-cohesive subsoil, jetting a fluid medium down, whether from the foraminous piping or from a nearby auxiliary member such as a hollow stanchion, to fluidize the subsoil, and pressing the piping downward until emplaced in the subsoil.

Foraminous piping is characterized by having numerous openings (foramina) enabling a fluid medium—such as water, air, or an air/water mixture—to be jetted radially outward from the piping to fluidize adjacent subsoil. The inventive apparatus of the invention also includes means, for pushing or pulling the piping into the subsoil, such as rotatable earth augers plus closely adjacent or more remote means of interconnection. Also useful are adjunct means for removing fluidized soil and/or objects therein from the vicinity of the lowering piping, and for securing the piping in place within surrounding subsoil in the absence of such augers.

A more elaborate apparatus embodiment for practicing the inventive method comprises, besides foraminous piping, a plurality of stanchions, a placement pipe removably engage- able above and in alignment with individual stanchions. The placement pipe and any engaged stanchion are adapted to receive a fluid medium jettable into the top of the place¬ ment pipe and out from the bottom of the engaged stanchion. First, upright open-ended stanchions are placed along the route by jetting water or other fluid medium down from an upright placement pipe into, through, and out the bottom of each stanchion to fluidize subjacent subsoil, enabling the placement pipe and the stanchion to be pressed downward until the stanchion reaches a desired depth, usually at least half buried in surrounding subsoil, which settles around it after discontinuation of the jetting. Preferably the placement pipe contains a cable or equivalent means lengthwise (preferably inside) and extending sidewise to the exterior at its opposite ends, so as to be unwound at the bottom for attachment to the foraminous piping, then be wound up to draw the piping toward the stanchion, where the piping is attached by any suitable means, after which the cable is detached and the placement pipe is disengaged from the stanchion and removed. It will be understood that subsequently the stanchions or the piping or both may be removed with the aid of fluid jetted therethrough to fluidize the adjacent subsoil.

SUMMARY OF THE DRAWINGS

Fig. 1 is a perspective view of coastal land and water suitable for treatment according to this invention;

Fig. 2 is an overhead or plan view corresponding to Fig. 1, with piping to be installed laid out on dry land and with anchoring sites indicated offshore;

Figs. 3 and 4 are sequential side sectional elevations of such coastal region at preliminary stages in positioning piping of this invention; Fig. 5 is a schematized side sectional elevation of the same piping, so positioned, early in burial fluidization;

Fig. 6 is a schematized side sectional elevation in the vicinity of the piping bottom end during such installation;

Fig. 7 is a schematic elevational view similar to the" nearer edge of Fig. 1, showing contours of the land before and after beach stabilization with the described apparatus.

Fig. 8 is a schematic transverse elevational section of the same piping, similarly emplaced, used for fluidization; Fig. 9 is a schematic longitudinal elevation of such fluidization similar to Fig. 8 with slurry transport piping; Fig. 10 is a top plan view of a navigational inlet before operation of apparatus of this invention therein; and Fig. 11 is a similar plan view of the same navigational inlet location after operation of this invention therein. Fig. 12 is a schematic perspective view of a multiple piping fluidization arrangement useful in clearing and main¬ taining a navigable inlet channel;

Fig. 13 is a plan view of a multiple piping system bypassing sand from updrift to downdrift locations past such a navigable inlet channel; and

Fig. 14 is an alternative dual-pipe embodiment. Fig. 15 is a schematized end elevation of foraminous piping flanked by a pair of pull-down earth anchors useful in emplacing it; Fig. 16 is a schematized end elevation of such piping emplaced by earth anchor straddling it and used in the man¬ ner of "staples" boring into the subsoil;

Fig. 17 is a schematized end elevation of such piping being emplaced by a jacking device located alongside but spaced from the piping; and

Fig. 18 is a plan view of a zigzag arrangement of means emplacing or holding such piping along the longitudinal axis of the zigzagging;

Fig. 19 is a schematized side elevation of mechanism for raking out objects from the desired rest position of foraminous piping; and Fig. 20 is an end elevation of the last mechanism.

Fig. 21 is a plan view of a planned route along which foraminous piping is to be emplaced, showing stanchion sites ^' spaced therealong;

Fig. 22 is a side elevation of an upright open-ended stanchion engaged endwise by an overlying vertical placement pipe, partly cut away, lowering the stanchion into non- cohesive subsoil;

Fig. 23 is a similar view of the same apparatus with the stanchion lower in the subsoil and being lowered further thereinto;

Fig. 24 is a similar view of the same apparatus with the stanchion at rest in the subsoil and with fluidizing piping at rest nearby and connected to a cable extending from the lower end of the placement pipe; Fig. 25 is a view similar to Fig. 24, with the fluidiz¬ ing piping being lowered into the subsoil by reason of downward fluid jetting from the piping into the subsoil plus retracting of the cable;

Fig. 26 is a similar view showing the fluidizing piping at rest attached to the stanchion;

Fig. 27 is a view similar to Fig. 26 but without the placement pipe and with fluid jetting sidewise into the sub¬ soil and adjacent water;

Fig. 28 is a somewhat similar view showing a pair of adjacent stanchions flanking the route and with fluidizing piping in place for each stanchion so as to make a wider depression in the subsoil.

The scale is variable in the foregoing diagrammatic or schematic views, so as to permit appropriate emphasis of com¬ ponents or features. Corresponding items are identified in successive views by like reference symbols, often augmented by increments of a hundred for successive embodiments.

DESCRIPTION OF THE INVENTION

Fig. 1 shows, in perspective, section 10 of waterfront property having several successive portions ranging from high and dry land portion 11 at the far left, sometimes dry and sometimes wet or intertidal beach portion 15 just to the right thereof, and lower seafloor portion 19 at the near right—by way of an ocean, sea, lake, river, estuary, delta, or the like. Boundaries (broken lines) between adjacent por- tions are marked along mean high water (MH ) line 13 between the dry land and the intermittently dry/wet beach, and along mean low water (MLW) line 17 between beach and sea, etc.

Fig. 2 shows, from overhead, a preliminary layout for apparatus of this invention. On dry land just above the MHW line is a string of dual piping assembly 20 (close parallel lines) . Near the bottom of the view and below the MLW line is a zigzag or double line 18 (crosses) of sites for earth anchoring means for the piping.

Fig. 3 shows from the side (with limited sectional shad- ing) same section 10 of waterfront with auger-like earth anchors 30, each having a rope-receiving, preferably open, loop at its top end, preliminarily placed in the planned double row. Thus, earth anchor 31 in the seaward (or right- hand) row has rope 5 tied thereto; the rope extends up to and over the dual-pipe assembly (20) and then underneath it and back through the top end loop of earth anchor 32 in the landward (or left-hand)row; finally, the free end of the rope is left available onshore, preferably above the piping. It will become apparent that pulling to the left on the end of rope 5 would pull the piping assembly down into the water and against the landward row of anchors, whereupon one of the rows preferably is removed.

Fig. 4 shows a close-up of piping assembly 20, sec¬ tioned transversely and located between the lines of earth anchors, represented by seaward anchor 31 shown in solid lines and landward anchor 32 now shown in broken lines to indicate removal thereof—as with the rope, after detachment thereof from the remaining, previously tied anchor. Piping assembly 20 is seen to comprise upper or working pipe 21 and lower or installation pipe 29 suitably secured together by suitable means (not shown) . Earth anchors 31 and 32 have open loop 33 at the top end and auger-like lower end 39. Affixed to the intermediate portion ^' of anchor 31 ap¬ proximately midway of its ends and retained by upper and lower nuts 34 and 36 flanking it is retaining bracket 35, which extends horizontally and fastens to the pipe assembly, as by passing partway around the installation pipe. The auger ends of the anchors are shown screwed into the sub¬ soil. Flow of fluid (arrows) out from the lower part of the latter pipe is indicated as having indented the top surface of the underlying subsoil 19 a bit. Fluid supply hose 28 is shown leading to installation pipe 29, and vertical riser 40 leading from working pipe 21, both well behind the plane of this view.

Fig. 5 shows piping assembly 20 free of the positioning rope and beginning to be buried in place. Lateral openings 23 are shown at opposite sides of working pipe 21, whereas the lowermost part of installation pipe 29 has openings 27 through which fluid (indicated by straight arrows) is exit¬ ing the pipe and is producing vortices (arcuate arrows) in the water between the pipe and underlying non-cohesive sub- soil of seabed 19. The vortices entrain subsoil particles (mostly sand) and fluidize it enough to enable the piping to be pulled downward by gravity and manual or mechanical screw¬ ing of the earth anchor(s)—see Fig. 4—downward at the same time or from time to time. Suspended particles settle wherever movement of the water under the influence of the fluid from the installation pipe and/or other currents may happen to carry them.

Fig. 6 shows the lower part of installation pipe 2 with its openings 27 much as in Fig. 5 but with the open en of slurry hose 26 inserted at the left into the turbulen space between the pipe and the underlying non-cohesive sub soil (mostly sand) . Slurry pump P shown at the other end o the hose may be locally or remotely situated. Intrudin from the right into the space between the installation pip and the subsoil is accessory fluid injector or vibrator 2 to cope with any obstacles in such space, as by stirrin them to be withdrawn by the exhaust hose or dislodging the for removal from the space, whether thereby or otherwise.

Fig. 7 shows, in a schematic elevational view, locatio 10"—i.e., location 10 after stabilization of original loca tion 10. Riser 40 is upright from connection with workin pipe 21 of piping assembly 20. Water is drained by pump 4 shown at the top of the riser and is discharged at an ap propriate distance therefrom. Also shown connected to th working pipe is generally horizontal cleanout line 42 exten ing seaward; it will be understood that such line enable sand accumulated in the pipe to be flushed out to sea rathe than to be picked up by the discharge pipe—in the interes of extending the working life of drainage pumps intoleran of sand. Alternatively, an electric submersible pump may b located at the base of riser 40, with its discharge int seaward line 42 through a check valve to prevent seawate from entering working pipe 21 therefrom.

Land contours before and after beach stabilization wit the equipment just described also appear in this view. Th original rapid fall-off of beach (solid line) has been re placed by a higher and more slowly descending land surfac (broken line). A "lazy 8" pattern of shading with its lef lobe 4 covering the piping assembly and its right lobe just below the original seafloor, represents optional star tup transfer of seafloor subsoil to cover the piping as sembly to a greater depth than accomplished by fluidize emplacement, as through displacement through scraping of th right lobe subsoil landward to occupy the left lobe.

Adequate or excessive beach accretion may suggest removal of the stabilization piping and seaward relocation of it—perhaps somewhat sooner than the time of this view. A simple but effective and inexpensive procedure for doing so is described hereinbelow. Where the earth anchors are buried completely, as they may well be, a buoy attached to the hooked top end tends to remain in view. Alternatively, buried metal earth anchors can be detected magnetically.

In normal fluidization uses, the piping tends to remain visible—or at least visually locatable, as by a depression in the seafloor. Indeed, a principal fluidization use is to create and maintain a channel along the piping, such as for navigational purposes. Concurrent or separate fluidization uses include enable sand or other non-cohesive subsoil not desired at its existing location to be transported to a more desirable place. Examples of both uses follow.

Reference numerals in the fluidization embodiments for features or components similar to those in the preceding sta bilization embodiment are one (or more) hundred larger for convenience in cross-reference and to save undue repetition. Non-analogous items generally have dissimilar numbers in the respective series. For example, features of the embodiment in the next two views are numbered in the 100 series, and those in the embodiment of the view next succeeding them is numbered in the 200 series.

Figs. 8 and 9 show location 110 (quite stylized) with seafloor base into which piping assembly 120 has been sunk well below pre-existing seafloor 119, forming V-shaped chan¬ nel 116 (Fig. 8). Stippling indicates the water having fluidized subsoil (sand) content. Water 118 above the level of the surrounding seafloor carries little or no sand and is shown clear. In the longitudinal view of Fig. 9 the channel bed slopes downward from its remote end to its end nearer riser 140. Exhaust line 126 also dips in the deep end of the channel to aid sand removal so as to maintain the chan¬ nel at appropriate depth and width (based upon the angle of repose of sand) .

Fig. 10 shows, from overhead, navigational inlet loca¬ tion 210 in poor condition. A large open arrow indicates the drift of water past serpentine inlet 200, defined in part at its seaward end by updrift jetty 201 and downdrift jetty 202. Located near that end of the inlet is seaward shoal 204 (broken line) and similarly near the landward end of the inlet is shoal 206, the two shoals effectively block¬ ing the inlet except for very small boats or rafts.

Fig. 11 shows location 210' (otherwise like location 210) after installation of fluidization according to this invention. Centerfed fluidization piping assembly 220 ex¬ tends both seaward and landward near the seaward end of the updrift jetty. Relatively straight inlet 200' has replaced serpentine inlet 200. The landward end portion of piping as- sembly 220 is central to the straightened inlet, and landward shoal 206' is greatly diminished in size. The seaward end of the piping assembly splits shoal 204' into two unequal parts. Exhaust riser 226 is affixed to updrift jetty 201 and has lateral discharge line 224 terminating (end arrow) onto downdrift beach 215.

Fig. 12 shows in stylized form wide-channel three- branch piping assembly 320 of this invention, without any attempt (because of the scale) to show its dual pipes on each ^' branch. Upstanding platform 312 supports exhaust riser 326, as well as fluidizing risers 320.

Fig. 13 shows modified three-branch embodiment 320' in¬ stalled at the previous inlet location (here designated 210). The fluidizer of Fig. 11 is still in place and main¬ taining the channel well. The three-branch fluidizer embodi- ment is installed just to the updrift side of jetty 201, ar¬ ranged like an arrowhead and terminating near the seaward end of the jetty, which supports exhaust riser 226 just as before, from which transport line 224 extends to downdrift beach 215. The centerfeed of the piping assembly is omitted here, as are the earth anchors or other securing means, to simplify the relatively small-scale view.

Details of fluid supply to the piping assemblies in the apparatus embodiments of the preceding and following views are omitted in the interest of clarity of illustration of features less familiar to ordinarily skilled persons. Fig. 14 shows alternative "barbell" embodiment 420 of dual-pipe assembly according to this invention. An inter¬ mediate portion of downward pulling earth anchor 431 is seen (bisecting the assembly) . In this embodiment two side-by- side pipes 421 and 429 joined by bracket 424, to which the anchor fastens, are arranged so that during fluidizing for emplacement their openings jet fluid mainly downward (solid arrows). Once the pipes are in place, usually partially buried, the openings are reoriented to jet fluid mainly laterally outward and apart (broken arrows). This is done by rotating the pipes (or close-fitting foraminous sleeves— external or internal—not shown) about their longitudinal axis, so that during use, whether for stabilization or fluidization, their active openings will be oriented for best effect, as in the previously described working pipes of this invention. Such convertibility is possible also with over-and-under dual piping but is usually more important with side-by-side embodiments according to this invention.

Figs. 15 to 20 show alternative embodiments of ap¬ paratus useful in burying piping for use in subsoil fluidiza- tion or stabilization.

Fig. 15 shows, in schematized end elevation, embodiment 510 of foraminous piping flanked by pull-down means used to emplace it. Pair of earth anchors 530, 530' are bridged by tie bar 535, whose ends are retained detachably to the respective anchors between upper and lower nutlike collars 534, 534' and whose center is held by vertical pushrod 550— here indicated by an adjacent arrow as moving downward. The pushrod has alternate light and dark segments along its length, the latter corresponding to spaces between protru- sions. Inverted V-shaped bottom end 559 of the pushrod straddles upper pipe 521 overlying attached fluidizing lower pipe 529 (with arrows).

Fig. 16 shows somewhat similarly to Fig. 15 embodiment 610 but without any pushrod. Here tie bar 635 is bowed downward at the ends by flanking pair of earth anchors 630, 630'—which have been driven staple-like into the subsoil by such means (not shown) as manually wielded sledge hammers or preferably a pile driver with a suitably shaped lower end to receive the "staples" while avoiding the piping.

Fig. 17 shows embodiment 710 in which piping pair 721, 729 is being emplaced with the aid of pushrod 750 with in- verted V-shaped bottom end 759 straddling the upper pipe. This pushrod is in rack form with teeth 755 along one side, ^' fitting into ratchet means 756 with actuating handle 757 ex¬ tending from it (arcuate double arrow). The ratchet means is mounted on the end of horizontal arm 776 of jackpost 770 which has brace 774 from the arm to top end 771 of the post, whose bottom end 779 is buried in subsoil 719. Pump P' has intake line 726 (with arrow) extending alongside the pushrod into the excavation and has outlet line 724 discharging removed sand onto heap 715, as onto a beach needing replenishment.

Fig. 18 shows schematically arrangement 800 of in¬ dividual sites 810a to 8lθf of anchoring means for piping 821 with intervening zigzag tie down means 835a to 835e, shown with broken circles overlying the piping as allowance for associated pushrod or equivalent means.

Figs. 19 and 20 show schematically, in respective side and end elevations, embodiment 910 of upper and lower piping 921, 929 surmounted by rake means 900. Transverse rollers 906, spaced above and along a horizontal length segment of the piping, support an endless rake belt 908 of upper and lower flights 901 and 909. The belt carries U-shaped tines, upright in the upper flight and inverted in the lower flight, each with inwardly extending vertical and horizontal bristles 903 spaced from each other. Supporting and driving means for this rake means are omitted but can be readily visualized.

Practicing the foregoing embodiments of this invention in their various aspects is readily understood in the light of the foregoing description and illustration.

It will be understood that for convenient installation and possible removal the piping is conveniently provided in modules of about a hundred meters (or submultiples thereof), with conventional provision for ready assembly and disas¬ sembly. Materials and accessories are considered following the description of the various illustrations and operational commentary. It will also be understood that variations in the identified embodiments often may be interchanged in part to produce additional modifications or embodiments.

As is apparent from the sequence of Figs. 1 to 6, dual piping of this invention may be laid out, preferably above mean high water, parallel to the shoreline. Locations for earth anchors are surveyed and marked, as with stakes, op¬ tionally with buoys tied thereto, preferably at a location a few feet under the mean low water level.

The earth anchors are positioned along a zigzag line (or two parallel lines) substantially parallel to the shoreline and are given a couple turns to secure them in the seafloor. Then ropes are passed over and under the piping and both ends are carried to the sea anchors , where one end of each is tied to the top loop of one of the seaward line of anchors, and the free end is passed through the top loop of a nearby landward anchor and is carried back up and over the piping, whereupon a pull on the free ends of the ropes will slide the piping down the beach and into the water and up against the sandward row of anchors. The end of each rope is then removed from the seaward anchor to which it was tied and is tied to the landward anchor, which is unscrewed and is then pulled onto shore. Alternatively it may be toted into place manually or be carried by floats and simply steered into place and dropped overside. Water and/or air is pumped to the installation pipe, either in a steady stream or pulsating, as may be desired where the generally non-cohesive soil is appreciably lumpy.

Fluid jetted from the downward directed openings in the in¬ stallation pipe stirs up the subsoil (usually sandy) and it becomes fluidized by the adjacent water, whether the fluid is air or water. Resulting loosening of the fluidized sub- soil enables the piping assembly to sink, and it is pulled downward by manually or mechanically rotating the earth anchors about their vertical axis so as to screw them downward into the sea-floor. If desired, fluidized subsoil is exhausted from the vicinity by a vacuum hose and is deposited elsewhere. Once the installation pipe has reached the desired level, preferably a meter or more below mean low water, and is buried to the desired extent, fluid ejection from it is discontinued. The piping assembly can be covered to greater depth with subsoil, if desired, as by scraping it from a nearby location further offshore. At such a depth, water will drain into the working pipe, and can be removed therefrom by pumping out from the riser attached thereto.

As there usually is an approximate balance between transport of subsoil toward and away from the beach by the onrush and the retreat of waves, removal of some of the water from underneath via the working pipe readily tips the balance toward deposit of a bit more sand than is carried back. Gradually, over weeks and months, the shoreline rises and builds seaward, thereby stabilizing the beach. Buildup of beach and eventually dry land over the stabi lization piping suggests that the piping be removed and be moved seaward or be installed elsewhere. Removal is ac¬ complished similarly to installation, by fluidizing the sub¬ soil in which the piping is buried. Both the installation pipe and the working pipe may be provided with fluid so as to loosen and fluidize the overlying soil, which may or may not pinpoint the piping sufficiently to aid its ready removal. Once found, the earth anchors can be unscrewed, and with sufficient fluidization and lifting the piping can be freed and either be provided with floats or be taken on board a vessel to be transported to a new location.

At a fluidization location, such as to maintain a navigation inlet, the dual piping of this invention is emplaced in like manner as for beach stabilization. Then, however, after the fluidizing flow to the installation pipe is terminated, fluid is supplied to the working pipe for ejection into the surrounding subsoil to fluidize it for removal. If prevailing water currents fail to convey the fluidized material to a desired location, an exhaust line may help. Moreover, instead of piping fluidized material to a remote pump, a slurry pump can be located nearby to remove the sand or similar non-cohesive subsoil to a desired loca¬ tion on a barge or at the far end of a transport line. In this manner the fluidization not only enables navigation channels to be opened and be maintained, but removed sand can be deposited wherever a beach needs it.

The practice of this invention in its various aspects does not require any unusual materials, although readily available materials may be customized for use according to the invention. Dual piping, if not already available for whatever purpose, can be made up of two pipes welded, banded, or otherwise fastened together. Whether integral or fastened together and separable, the over-and-under and the side-by-side pipe embodiments differ chiefly in their rela¬ tive sizes (preferably unlike in the former and alike in the latter) and in as-installed orientation of their openings for fluid passage between their interior and the exterior: underneath for installation, and otherwise--preferably lateral—for fluidization (both sides for an overhead work¬ ing pipe and one side only for side-by-side pipes) . In sta- bilization usage, where flow may be relatively slow, pipes may tend to clog unless back-flushed, preferably in a pulsat¬ ing manner. To preclude clogging by animal, plant, or mineral agents, pipes used for stabilization may be provided with close-fitting, preferably removable mesh, or otherwise porous, jackets—as common in underground irrigation systems for a like purpose.

The pipes may be made of metal to assist their burial or may be made of plastic to aid their handling and removal, also to preclude clogging from electrolytic action. The flow openings in the pipes may be produced by drilling or piercing, or they may be provided during manufacture of the pipes, as by molding or otherwise. They may be provided with suitably directional resilient flapper valves, Pipes formed by rolling may be provided when flat with a notched or slotted edge or with spacers, to form openings when par- tially overlapped by edges, as in Chapin's U. S. patents (e.g., 4,642,152).

In fluidization of non-cohesive subsoils or like materials, the fluid of choice is usually water, as it is here most of the time, but sometimes air or a.mixture of air and water may be preferable, as when piping being emplaced encounters clayey, pebbly, or obstacle conditions that can better be fragmented by exposure to pulsating flow—which may also be provided by variable-flow water pumping. As ex¬ perience is gained, operators learn what fluid is preferable for removal of various obstacles. The rake mechanism of this invention will cope with most debris that may be encoun¬ tered in the subsoil because movement of sandy soils tends to stratify less dense objects upward and denser ones downward, so lighter objects usually are found on or near the surface, where they are readily removable, and heavier ones are buried deeper than is pertinent to this invention.

Earth anchors are conventional, usually made of steel, obtainable in various sizes. Collars or other attachments are easily welded to the anchors. Tie bars and pushrods are readily available, in steel or other metal. Jacking devices also are well known and can be built or purchased. The rake mechanism is custom-made but can be duplicated easily from the description and illustration in this specification.

The apparatus embodiment of the present invention shown in Figs. 21 through 28 has its features numbered in the 1000 series without necessarily corresponding to numbering of the features previous embodiments (in various hundred series) .

Fig. 21 shows in plan inlet region 1007 (broken lines) to be fluidized. Flanking piping route 1010, dual rows of anchor means 1030 are tangential to the route and spaced at alternating intervals. Fig. 22 shows in elevation surface 1002 of body of water 1004 overlying surface 1006 of subsoil 1009 with depression 1008 therein, and features emplacement apparatus including upright placement pipe 1020 with its top above the water surface, and upright stanchion 1030 as potential anchor means connected to the pipe and above the subsoil depression, both moving downward (arrow). Bottom end 1029 of the pipe is snugly engaged with top end 1031 of the stanchion. Intermediate portions of both the placement pipe and the stanchion are omitted between their ,respective ends (bringing the top of the pipe too close to the water sur¬ face) to conserve drawing space. End-to-end bore 1025 of the placement pipe and end-to-end bore 1035 of the stanchion, are aligned with and open to each other. Fluid supply tubing 1022 (with arrow into it) has valve V in it and is attached to top end 1021 of the placement pipe. Arrows from bottom end 1039 of the stanchion downward into depression 1008 signify a fluidizing flow out from bore 1035 into the subsoil below. An arrow downward alongside the placement pipe shows that the entire assembly is being lowered. Hous- ing 1024 with winding handle 1026 is affixed at the top of the pipe to carry a cable-storage drum (inside), and prong 1033 extends upright at a side edge of the top of the stanchion—for purposes illustrated in subsequent views.

Fig. 23 shows the same emplacement apparatus similarly but at a greater depth of insertion of the stanchion into the subsoil. Here the junction of pipe bottom end 1029 and stanchion top end 1031 is at the undisturbed subsoil level. The entire assembly is still being lowered (arrow alongside) to a greater depth of insertion of the stanchio —and part - of the pipe--thereinto. Water flow continues from the supply tube into the pipe top end and out the bottom end of the stanchion to fluidize the subsoil. Hence, the subsoil

depression (redesignated 1008') is deeper than before. At such level in this view is upright prong 1033 affixed to one side of the stanchion top—for a purpose that will become more readily apparent in the next view. Fig. 24 shows the same emplacement apparatus at rest, with the stanchion buried and with the subsoil having filled back partially into the formerly fluidized opening (now redesignated 1008"). Cable 1032 unwound from the drum (not visible) in housing 1024 enters the placement pipe sidewise through an opening (not visible) at or near the top of the pipe and r*uns down the length of the pipe to and partly around roller 1028 and sidewise through an opening at . of near the bottom of the pipe. Foraminous piping assembly

1040 rests on the undisturbed subsoil surface with the free end of the cable temporarily secured to an opening in flange

1043 joining upper (working) foraminous pipe 1042 and lower

(installation) foraminous pipe 1048.

Fig. 25 shows the same emplacement apparatus with cable 1032 being wound up (curved arrow at handle 1026 and straight arrow alongside the cable inside placement pipe 1020) and drawing foraminous piping assembly 1040 down into the opening alongside the now stationary stanchion. Instal¬ lation (lower) pipe 1048 thereof is jetting water downward to fluidize the subsoil into which the assembly is moving. Fig. 26 shows the same emplacement apparatus with the foraminous piping assembly in place with the opening in flange 1043 thereof to which the cable had been temporarily fastened now fitting onto prong 1033 at the top end of the stanchion. The cable is now at rest, wound up to keep it taut from top to bottom sidewise openings (no arrow) .

Fig. 27 shows such stanchion and aligned overhead place¬ ment pipe in broken lines to indicate that the embodiment is shown at a location therebetween (or after their removal). Working (upper) pipe 1042 of the foraminous assembly is jet- ting fluid laterally (arrows) to fluidize adjacent subsoil. Accordingly, coherent subsoil (stippled) is spaced laterally from the fluidizing pipe.

Fig. 28 shows similarly one stanchion and one attached foraminous piping assembly in each of dual rows of anchor means. Depressions produced in the subsoil by the respec¬ tive assemblies have merged into a broad expanse designated 1007' corresponding in width and depth (and length) to the desired inlet region 1007 shown in plan in Fig. 21.

The sequence of steps in practicing this embodiment of the invention is apparent from the foregoing description of sequential stages in the process, which may be considered to include two successive method sequences: first, emplacing anchoring means; then emplacing foraminous piping means— then actual anti-shoaling working of the latter means.

The first emplacement conveniently comprises sequential steps of removably engaging the lower end of a placement pipe, having a cable extending sidewise therethrough to the exterior at both of its ends, to the upper end of an open- ended stanchion, and orienting the engaged placement pipe and stanchion upright with the bottom end of the stanchion on such non-cohesive subsoil; jetting fluid into the top end of the placement pipe, through such pipe and the engaged stanchion and out of the bottom end of the upright stanchion into the subsoil so as to fluidize such subsoil, and press¬ ing the placement pipe down until the stanchion reaches a desired buried depth, and discontinuing jetting the fluid through the engaged placement pipe and stanchion.

The second emplacement similarly comprises sequential steps of unwinding the lower end of the cable, outside of the placement pipe, and attaching such cable removably to the foraminous piping; jetting a fluid from the foraminous piping downward onto and into such subsoil so as to fluidize such subsoil, winding up the cable and thereby drawing the foraminous piping to the stanchion, and attaching such piping to the stanchion; then discontinuing such jetting of water from the foraminous piping, disconnecting the cable end from the foraminous piping, and finally disengaging the pipe from the stanchion, leaving the foraminous piping at¬ tached to the stanchion at desired depth in the subsoil.

The working of the foraminous piping conveniently com¬ prises the steps of jetting fluid laterally therefrom at in¬ tervals sufficiently frequent and forceful to fluidize the subsoil in the vicinity to prevent shoals from forming along the route. It will be understood that the piping is con¬ nected to a source of fluid, usually water but optionally mixed with air or sometimes even entirely air, under such pressure as to jet it vigorously enough to fluidize the sub¬ soil. In many instances, such fluidization can be timed to take advantage of natural currents to remove the fluidized subsoil to a preferred location. Otherwise, the fluidized subsoil can be removed by eduction means, including flexible tubing moved along the route on a barge or otherwise and deposited on such a barge or more directly through the edύc- tion means into a longshore current or even onto a nearby beac .

Although over-and-under foraminous piping has been il¬ lustrated and described, including a lower installation pipe (adapted to jet fluid downward) and an upper working pipe adapted to jet fluid laterally or sidewise, a side-by-side foraminous piping arrangement may be substituted wherein the pipes are adapted to jet fluid down and laterally apart with or without adjustable control of direction.

Although the stanchions have been shown smooth-sided, a circu ferentially ribbed or otherwise roughened surface may be sustituted to enhance their anchoring. For example, a rib with a semi-conical downward tapering cross-section is more conducive to insertion than to removal. However, it should be noted that removal can be readily accomplished by reconnecting the placement pipe and forcing fluid down through the pipe and out the bottom of the connected stanchion, thereby fluidizing the surrounding subsoil, then lifting both. The foraminous piping assembly may be removed beforehand or concurrently by fluidizing the installation pipe and optionally the working pipe, and lifting out the foraminous piping assembly (assembled or dissassembled) .

INDUSTRIAL APPLICABILITY

Coastal management methods based upon dredging will be augmented in substantial part by addition or substitution of fluidization and dewatering techniques. Market demand for pumps and foraminous piping will increase drastically, as will the demand for suitable anchoring means employed in emplacement of such piping for such uses. The resulting enhancement of coastline, whether by beach stabilization and/or navigable channel or harbor maintenance will become a recognized occupational specialty and will employ numerous people in supporting functions. Early signs of such growth are becoming apparent in prominent coastal regions, such as California, Florida, and the northeastern part of the United States, as well as in Europe. Preferred embodiments and variants have been suggested for this invention. Other modifications may be made, as by adding, combining, deleting, or subdividing compositions, parts, or steps, while retaining all or some of the ad¬ vantages and benefits of the present invention—which itself is defined in the following claims.