The present invention relates to a hydraulic tie rod for construction projects ensuring the protection of the construction structures against damage caused by earthquakes and hurricanes.

Background of the invention

The prior art scientific endeavours have focused on the anti-seismic and anti- wind protection of construction works. To deal with these natural phenomena successfully, efforts have mainly focused on improving the ground, the construction materials as well as on improving the German and the American static regulations. All these improvements produced good results, however, increased significantly the construction costs as regards the use of cement and steel and did not eliminate currently existing problems. There are still construction structures sustaining damage and losses, or even destroyed, by earthquakes and hurricanes and all that despite the improvements made. It is therefore necessary to redefine how the earthquake and wind forces are exerted onto the building structures and to re-examine whether the existing construction materials work together as expected for there must be some mistake made somewhere contributing to damage and destruction. To start with, regardless of how strong a building structure is, it will collapse if the ground on which it rests is unstable. To this date, ground improvement is achieved by ground compacting using end-bearing piles and friction piles or the vibration technique in order to prevent its fiuidization during an earthquake. Considering that this kind of ground improvement which moreover requires soil sampling prior to its compaction is very expensive, it is not carried out in minor construction works and therefore such works are left exposed to serious risk should the ground subside. There is therefore a need to devise a mechanism that prevents a building structure from sliding on either soft soil or rocky ground during an earthquake. Another issue to be considered is whether the German or the American static regulations are adequate not so much as regards the strength of materials - the mechanical strength of materials is well known - but as regards the additional forces that are being generated during an earthquake, forces unknown in the prior art and once these additional forces are identified, an appropriate mechanism can be worked out to eliminate them and prevent damage to the structure. Figure 3 presents an analysis of the known static mechanics forces wherein a tensile force (42) is generated by two forces acting along the same axis but in opposite directions. It is a known fact that concrete (43) does not stand up to tensile forces and fractures. Steel (44) however stands up well to tensile forces and for this reason it is used together with concrete in appropriate locations to help concrete withstand the tensile forces generated. Compression (45) is another force generated when two forces are acting along the same axis but in opposite directions. Concrete (43) exhibits nearly the same behaviour as steel (44) in compressive loads. Shear force (46) is another force which occurs when two forces are applied on parallel axes but in opposite directions. This force is exerted between steel (44) and concrete (43) at their point of contact. Buckling forces (48) occur when opposite forces are acting along the same axis but the distance (height) of the material on which they are applied is six times greater than the smallest dimension of its base. When such forces are exerted, the material tends to buckle like α razor blade (49) instead of taking the shape of a barrel (43) as in compression. Finally, there is the torsional force (50), which is generated when materials are subjected to twisting stress.

We will now consider the way these types of forces analysed above act on the building structure during an earthquake or under exceptionally high wind conditions. In situations involving an earthquake or very high winds (hurricanes), lateral forces are generated (see Figure 4 (40)). The building frame column (34) sways left and right as a result of the oscillations produced by the earthquake. During the swaying motion of the column, as seen in Figure 4, when the column tilts left, tension forces are generated (42) on its right side and compressive forces (45) on its left side. It is for this reason that steel is laid externally to "absorb" tensional forces from both sides alternately. When the column tilts to the right, the exact opposite occurs to what was just previously described and goes on throughout the duration of an earthquake. At this point, though, we are called to answer the question why columns break at point (55) although our static calculations on these forces are correct, the answer is simple. We know that steel withstands tensile stress (42) and our calculations are carried out on the basis of that knowledge. We do not, however, take into account the rest of the forces being generated. The first of these unknown forces, not taken into account usually, is that of buckling (48) generated in both concrete and steel and none of these materials can withstand buckling effectively. When column (34) tilts, the concrete in the column produces a steel displacing force (forcing steel to bend over backwards, so to speak) at point (60) and up to point (59). This happens because concrete that's on the inner side of the steel (44) withstands the compressive force generated between the two materials and this leads to an outward displacement of steel tending to push it out of the column. This being the case, steel cannot carry out the task of standing up to tension, this being the reason it was originally placed in the column. Another omission, that is not statically calculated, will now be shown using a simple illustration. If we take a candle (Figure 3 (52)) and break it near its base (53) we notice that its candlewick (51) will come out the bottom part of the candle, which provides less resistance in comparison to the top part of the candle, which is longer. This happens because the tensile force (42) generated on the candlewick (51) during breaking will create a shear force between the candle and the candlewick, which [shear force] is smaller in the bottom part of the candle compared to the other opposite shear force generated in the top part of the candle and this is because whenever tension occurs, there will always be shearing in response. This is exactly what happens to column (34) in Figure 4. Steel section (44) from point (58) to point (60) is less in length than steel section (44) from point (57) to point (59), thus concrete resistance to shear (46) in section from (58) to (60) is lower resulting in the steel being pushed out of the concrete in that section and leading to the collapse of the structure. Nearly always in building structures which collapse during an earthquake, column fracture occurs approximately at the same height as shown in Figure 4 with the steel being pushed out - not fractured, in other words, while steel can withstand much greater tensional forces, these forces are cancelled out due to concrete failure to resist the shear forces generated in the column section from point (58) to point (60). It follows from the foregoing description that a new method of laying steel within the column is required that would only allow the generation of shear forces (42) that steel (44) can withstand and compression forces (45) that concrete (43) can withstand. In other words, reinforcement should be laid in a way that prevents the generation of shear forces (46), between steel and concrete, which concrete cannot withstand.

All building load-bearing elements are constructed in a vertical and horizontal and rarely in a slanting manner, i.e. vertical columns, monolithic horizontal slabs, trusses, which collapse because, in columns (34), their vertical axis bends beyond the fracture point as stated earlier. Trusses collapse due to the buckling of their horizontal axis at the points of their contact with the columns owing to the wavy motion that, during an earthquake, is transmitted through the ground and which turns individual column bases and the columns themselves into column fracturing pistons. Trusses will also collapse due to the compressive (45), tensional (42), shear (46) and torsional forces exerted at the points of their support as a result of the "left and right" swaying of the building's framework caused by an earthquake or very high winds.

Brief description of the invention

The principal object of the hydraulic tie rod for construction projects of the present invention as well as of the method for constructing building structures utilizing the hydraulic tie rod of the present invention is to minimise the aforesaid problems associated with the safety of construction structures in the event of natural phenomena such as earthquakes, hurricanes and very high lateral winds. According to the present invention, this can be achieved by a continuous pre-stressing (pulling) of both the building structure towards the ground and of the ground towards the structure, making these two parts one body like a sandwich. Said pre-stressing is applied by means of the mechanism of the hydraulic tie rod for construction projects. Said mechanism comprises a steel cable crossing freely in the centre the structure's vertical support elements and also the length of a drilling beneath them. Said steel cable's lower end is tied to an anchor-type mechanism that is embedded into the walls of the drilling to prevent it from being uplifted. Said steel cable's top end is tied to a hydraulic pulling mechanism, exerting a continuous uplifting force. The pulling force applied to the steel cable by means of the hydraulic mechanism and the reaction to such pulling from the fixed anchor at the other end of it generate the desired compression in the construction project.

Detailed description of the invention There follows a detailed description of the present invention with reference to the accompanying drawings wherein:

Figure 1 is a three dimensional representation of the present invention's device of a rrydraulic tie rod for construction projects.

Figure 2 is a three dimensional representation of a building framework with hydraulic tie rods for construction projects fitted to the framework's vertical support points and also in the drillings beneath them.

Figure 3 shows the forces which are calculated in the static design of construction structures and it also provides an illustration with a candle.

Figure 4 shows the pathogenesis of a building framework column as well as an analysis of the forces acting destructively on the aggregates.

Figure 5 shows a building framework column with its base as well as the proposed structure in order to avoid said pathogenesis problems in case of an earthquake.

Figure 6 shows the proposed holding hoop for the steel cable-passage pipes and the steel-passage pipes inside the columns.

Figure 7 shows a house built without framework as well as the locations for installing the hydraulic tie rods.

Figure 8 shows a suitably configured steel framework for encasing old structures made of timber or other materials and the retrofitting of hydraulic tie rods on them.

Figure 9 shows a water dam as well as the method of installing hydraulic tie rods on it.

Figure 10 shows sections of a floating underwater road as well as the usefulness of fitting hydraulic tie rods to it.

With reference to Figure 1, the hydraulic tie rod (108) comprises two main components, namely, the pressure chamber (1) and the anchor (17), which are connected by a steel cable (2). The pressure chamber (1) comprises an integrated pressure chamber sleeve (8). Inside said sleeve, there is a pressure chamber piston (7) which slides up and down, just like a car engine piston, and is leak-tight to prevent the escape of pressure chamber air (or other fluid) into the internal ring of the pressure chamber sleeve (8). On the inside of said pressure chamber (1), in the centre of it, there is a welded pressure-tight steel cable carrying pipe (11); said steel cable (2) travels through said pipe while the inner part of the hole opening (109) of the pressure chamber piston (7) slides snugly on the external surface of said pipe. A piston terminal ring (6) is integrally mounted (as if one body) on the pressure chamber piston (7) and has two piston safety wire brackets (5) holding in their holes the safety wires (3), said wire brackets being held at the other end by sleeve safety wire brackets (4). Said piston terminal ring has a hole opening (109) through which said steel cable (2) comes out and is then fastened on the piston terminal ring (6) by a cable-fastening cone-shaped wedge (14). Said pressure chamber (1) has a pressure safety valve (9) that opens to release excess pressure from pressure chamber (1). It has also a hole opening with internal threading (10) for the supply of air (or other fluid) through a solenoid connection to the central automated pressure air (or other fluid) replenishment system. It follows, of course, that pressure chamber (1) is hollow internally to be filled with pressure air (or other fluid). The chamber piston (7) is solid and has an internal hole opening (109) in its centre. The steel cable (2) fastened to the terminal ring of the pressure chamber piston (7) once it passes through: (a) the opening of the steel cable receiving pipe (11) in the pressure chamber (7), (b) the steel cable passage pipe (Figure 2 66)), (c) the opening of the metal resistance pipe (Figure 2 (15)) and (d) the anchor sleeve (25), terminates and is fixed with cast metal inside the anchorage piston (26) which becomes a solid unit with the steel cable (2), which bears a knot (Figure 1 (22)) at the lower end of it for improved anchorage inside the anchorage piston (26). The anchorage piston (26) slides up and down inside the inner opening of the anchor sleeve (25). The anchorage piston (26) has integrally mounted on it an anchorage piston terminal ring (21). The anchor sleeve (25) too has mounted on it an anchor sleeve terminal ring (20) and an anchor threading (16) for screwing the metal resistance pipe (15) on to it via a corresponding threading similar to that of said anchor sleeve. Moreover, the anchorage piston (26) has another ring on it called piston rod bearing ring (24), having built-in hoops with holes for connecting it to the rods (27) through connecting ring rod rotary pins (28). The other end of the rod is connected to side blades (18), which also have hoops with holes connected to the anchor rods (27) through connecting side blade rod rotary pins (29). The anchor sleeve, too, has a sleeve rod ring (23), which has hoops with holes so that it can be connected through rods (27) and connecting rotary pins (28) to the side blades (18) embossed with indentations (19) for better anchorage into the drilling walls (31). A building framework can be seen in figure 2 with a lift and integrated hydraulic tie rods for construction projects in operation.

In another preferred embodiment, when the hydraulic tie rod for construction projects is to be used in particularly unstable ground sites, it may be provided with anchors bearing four cross-shaped blades (at 90° to each other) with the corresponding number of rods and connecting rotary pins. We will now consider the framework construction sequence and the manner in which installation and operation of the hydraulic tie rods is carried out. Once the ground onto which the building structure will rest has been prepared, holes are dug into the ground at the points where the individual bases (36) will be placed. Drilling (31) is carried out inside the holes. The steel cable (2) is integrated onto anchor (17). One end of the steel cable (2) is passed into the hole opening of the metal resistance pipe (15) and said metal pipe (15) is threaded onto anchor (17) via anchor threading (16). Once joined into one body, the bottom part of the anchor (17), together with the resistance pipe (15), is lowered first into the drilling (31). On the top side of said resistance pipe (15) there is mounted a flat steel base to regulate its lowering to the desired level and provide better resistance and propping of the individual base (36) on the metal resistance pipe (15). Then, the steel cable (2) projecting from the metal base of said resistance pipe (15) is progressively fed into the pieces comprising the steel cable carrying pipe (66) while progressively adding more pieces until rooftop slab (33) is reached. When concrete laying of the building framework has been completed, the projecting steel cable (2) is placed in the bottom side of the pressure chamber (1) and passed through the hole opening of the steel cable carrying pipe (11) pushing the steel cable (2) until it goes through the hole opening (109) of the pressure chamber piston terminal ring (7). Once the steel cable (2) emerges from the top of the hole (109), it is guided through the opening of a cone-shaped cable anchoring wedge (14) and the base of pressure chamber (1) is placed over the steel cable carrying pipe (66), and then the steel cable (2) is attached on the pressure chamber piston (7) and pulled up using standard traction equipment. As the steel cable is pulled by the traction equipment the following occur: an upward pull is exerted at the distant end of the steel cable (2) mounted on the anchorage piston (26), the metal resistance pipe is held in place by the concrete foundation of column (36) as does the anchor sleeve (25) which is fastened to the resistance pipe (15) by means of the anchor threading (16) and as a result of the pulling action the anchorage piston (26) sinks into the hole opening of the anchor sleeve (25). During this movement of the anchorage piston (26), the piston rod bearing ring (24) is held in place by the anchorage piston terminal ring (21) and is lifted forcing the anchor rods (27), through the connecting rotary pins, to move vertically upwards; however, piston rods (27) are prevented from being lifted upwards because of the resistance offered by other sleeve rods (27) operating via the same mechanism in a reverse and opposite fashion providing resistance to the action of the piston rods and thus the joint connecting and rotary pin of the side blade rod (29) pushes the support of the side blades (18) towards the walls of the drilling (31) and as a consequence the side blades (18) push on the walls of the drilling (31), which, in turn, retreat slightly thus anchoring the entire system. To remove the traction equipment up _^ on completion of the traction operation, the cone-shaped anchor wedge (14) is placed in the hole opening (109) of the piston terminal ring (6) and hammered down in order to get the steel cable (2) anchored. Then, once the commercial traction equipment is removed, the pressure chamber is set to the desired pressure level by connecting the internally threaded inlet (10) through a piping system to an automated air (or other fluid) pressure system, "electrical pump with controlled pressure chamber". This pressure (90) within the pressure chamber (1) is exerted in all directions i.e. forces the pressure chamber downwards and the pressure piston (7) upwards; however, because the pressure piston (7) is tied to the steel cable (2) through the cone-shaped wedge (14) it cannot rise but exerts a pulling force (42) on the steel cable (2) while the base of the pressure chamber (1) exerts compressive force (45) on the slab originating from the reaction created by the pressure (90) of the piston bottom (12) towards the bottom of the pressure chamber (1). Moreover, to absorb the vibrations a rubber insert (13) is placed between the pressure chamber (1) and the top slab (33). This compressive force of the hydraulic tie rod for

• construction projects is different from the compression generated by the weight of the floors. In a multi-storey building the weight of each floor is the same when all floors are of the same dimensions and is accumulated generating the compressive force. However, the oscillating motion of each floor during an earthquake is different, the higher the floor and the longer the duration of the earthquake is, the larger the amplitude of the oscillation, increasing gradually and causing the first, the middle and the top slabs to oscillate deforming their vertical axis into an S shape changing the relationship of the horizontal and the vertical axis of the building by 90° leading eventually to the collapse of the building.

In contrast, the compression generated artificially by the tie rod for construction projects (108) is an active compressive force without the oscillations that the slabs are subjected to and which are generated as a result of the inertia of the slabs to the lateral forces caused by an earthquake. This artificial compressive force exerted by the tie rod prevents buckling of the columns, unless the steel cable breaks, thus, giving us the possibility to utilise its full strength at 100%. In case the drilling walls (31) collapse due to ground fluidization on account of an earthquake, the steel cable (2) will remain under tension, while the anchor diameter (17) on the horizontal plane will increase providing compaction of the soil on the drilling walls (31). This is because of the continuous pressure the steel cable (2) is being subjected to by the air (or other fluid) pressure exerted on the pressure chamber piston (7) and the pressure chamber {1) forcing the anchor (17) to open and automatically improve the soil on the drilling walls (31). In the event of the soil subsiding under the base (36), the building framework will not tilt because its weight is "taken up" by the metal resistance pipe (15) and then transferred to the side walls of the drilling (31) through the upper rods (27) of the anchor (17) which are pyramidal in shape, and are linked to the lower rods (27), which are pulled by the rising motion of the steel cable (2), through connecting rotary pins (29), (28). Moreover, this mechanism generates only compression (45) and tension (42) forces on the concrete column and prevents the generation of shear forces (46), which the concrete cannot withstand (see example of Figure 4). Moreover, anti-vibration rubber inserts (Figure 2, (35)) are placed in order to absorb the vibrations generated by the vertical earthquake forces. These rubber inserts (35) are placed between the individual bases (36) and the continuous base (37) which is constructed in order to prevent ramming the trusses and the slab (33) caused by the up-down movement of the individual bases during the waveform motion of the ground generated by the earthquake. In this way, the continuous base (37) is converted into a rigid boat keel lifting the columns on the same horizontal axis of the continuous base (37), in other words, the horizontal axis of the continuous base does not change shape during the earthquake and there is no ramming by the columns. In conclusion, the greater the width of the columns the more effective the hydraulic tie rod for construction projects is.

In another especially preferred embodiment of the present invention, based on the above conclusion and on our attempt to achieve the greatest possible structural rigidity, four hydraulic tie rods (108) are placed at the four corners of a lift shaft (Figure 2, (32)) with sizable external side dimensions, as well as a separate individual base so that the resulting unit will be very rigid. Care is taken not to leave a joint-spacing (38) between the slab (33) and the lift (32) and between the continuous base (37) and the individual base of the lift (32). This combined structure exhibits the following behaviour during an earthquake: the rest of the framework is oscillating around the lift shaft touching on it at various points along the gap (38) just before the framework exceeds its fracture point and thus before it is subjected to fracture and collapse it touches on a rigid structure (lift shaft) or a cross-shaped rigid column and thus the vertical axis of the framework does not exceed its allowed fracture point and does not assume an S shape as a result of the inertia of the slabs mentioned above.

In yet another embodiment of the present invention, the hydraulic tie rod for construction projects may be used with reinforcement in the columns, particularly with pre-stressing which is usually applied to the trusses. This is a very innovative way of using the hydraulic tie rod of the present invention adding improved strength mainly to large structures wherein simply covering the external columns of the building structure may not be sufficient to give the structure full structural rigidity and protection. In order to achieve this and have a vertical pre-stressing of the steel, it must not be anchored within the concrete and for that reason the steel is guided (Figure 6, (44)) through pipes (65) which are fixed with a pipe holding hoop (64) comprising the central pipe (110) fastening, the steel passage pipes (72) fastening, and the pipe holding bars (73) bearing hole openings to allow the concrete to pass through (74). Pipes (65) and (66) are fastened into said fastening hole openings (72) and (110) once the steel (44) and the steel cable (2) have passed through the pipe and fastening hole openings. The same procedure is followed in fastening the remaining pipes one on top of the other. Figure 5 presents an illustration of a frame column (34) with an individual concrete base (36). It shows the method of installing hoops (64), tie rod-cable passage pipe (66), steel passage pipes (65), and metal plates (62) as well as the method of threading with the base tightening screw (70) and the tightening screw (69) for joining and extending the steel, it also shows steel cable (2) and steel reinforcement (44). There follows a description for the placement and the construction of column (34). Once the drilling (31) has been carried out, the anchor (17) is screwed on the metal resistance pipe (15) provided the steel cable (2) has been guided through its hole opening. The anchor is lowered inside the drilling (31) and then the metal base plate (62) is placed provided the steel cable (2) has been guided first through its central hole opening. Then we fasten all steel carrying pipes (65), as well as the main steel cable carrying pipe of the tie rod (66), to the metal plate (63) hole openings, provided the steel reinforcement (44) and the tie rod steel cable (2) have passed first through their hole (67) and then screwing steel (44) using tightening screws (70) on the bottom part of the metal plate (62) to prevent it from rising upwards. These pipes are held inside a partially finished formwork of the column by means of hoops (64) and when the pipes (65) and the steel (44) reach beyond the level of the slab, the column formwork is completed and the concrete is poured into the column formwork (34). When the concrete sets the pipes projecting from the slab are cut and metal plate (62) is placed on the projecting steel (44) with threading (68) taking care that the steel (44) and steel cable (2) get through the hole openings of the plate (63). The tightening and steel joining/ extending screw (69) is then screwed to the steel (44) threading (68) on its internal half threading (71), while the extension of the other steel is screwed on the other half internal threading of screw (69). Tensional forces on steel (44) and compressive forces on column (34) are generated during the fastening of the tightening screw (69) on the metal plate (62). This way, the required additional and desirable result of column compression is obtained, thus preventing the generation of shearing forces when the classical reinforcement method is utilized, i.e. pre-stressed concrete is produced in the framework column (34) by means of both the steel and the steel cable of the tie rod.

Based on the foregoing description, the advantages of using the hydraulic tie rod for construction projects can be listed as follows:

1) The structure's centre of gravity is shifted and is now located into the ground, making the construction structurally rigid. This is achieved by means of tightening the structure to the ground thereby forcing it to act as an integral body with the ground and not in isolation in which case it becomes vulnerable to lateral, destructive for the columns forces.

2) Permanent active compressive forces are developed, remaining constant even during an earthquake, exceeding the conventional tensional and shearing forces developing and prevailing during an earthquake following the current methods of concrete reinforcement in the columns, compressive forces which can be taken up by concrete to 100%.

3) Savings in terms of steel and concrete materials used, deriving from the fact that either the steel or the steel cable can be 100% effective to tensional forces considering that the hydraulic tie rod (108) does not offset the working tensional traction of steel or steel cable (2), which, in the case of passive steel and concrete reinforcement, is offset due to the failure of concrete to withstand the shearing forces developed between concrete (43) and the embossed part of steel (44). 4) The structure is prevented from being shifted because it is tied to the ground.

5) Structure sliding as a result of soil fluidization is eliminated. This is because of the shape of the anchor (17) and the "triangular pyramidal" bar arrangement pattern (27), combined with the continuous active compressive force exerted by the hydraulic tie rod and the resistance pipe (15).

6) The destructive forces applied on the structure during an earthquake are effectively checked by installing on the framework of Figure 2 effective systems for distributing the forces evenly, such as individual bases (36), continuous base (37), vibration reducing rubber inserts (35) and a single elevator (32) equipped with four hydraulic tie rods for construction projects.

7) The strength of the trusses at their point of support on the columns is increased due to the fact that at the point of support concrete is subjected to compressive forces and its resistance to shear forces generated between the concrete and the horizontal reinforcement of the trusses during an earthquake is increased.

The hydraulic tie rod for construction projects of the present invention can be used in various similar applications in the construction industry such as:

(a) Houses built employing methods not utilizing a concrete framework (Figure 7, (75)) wherein the strength of the brickwork (77) to the lateral forces generated during an earthquake is increased by inserting mortar joints, this increase in strength being due to the compressive forces (Figure 3, (45)) developed by means of the hydraulic tie rod for construction projects (108). In the case of houses built employing methods not utilizing a concrete framework, the hydraulic ties rods may be installed at the corners of the building and at intervals, around the structure perimeter, over the external brickwork, passing through the gap between the double brickwork, inside carrying pipes (66) terminating vertically into the drillings (31). The positioning of tie rod pressure chambers (1) on the top slab can be seen in Figure 7. Moreover, in such building structures a reinforced concrete bind- beam (76) and a continuous foundation (37) are constructed for better protection. In such building structures (75), equipped with hydraulic tie rods (108), built employing methods not utilizing a concrete framework, the cohesion, the strength and the adhesive ability of the joints (111) are greatly improved rendering these structures much more resistant to the lateral forces exerted during an earthquake, forces that ordinary brickwork cannot withstand. (b) Old houses, timber houses and water dams in artificial lakes (Figure 9), achieving additionally better ground water-tightness through compaction and improved resistance to lake-water pressure. In these cases, the hydraulic tie rods for construction projects may be used either during the construction stage when included in the design or may be retrofitted to reinforce old structures against earthquakes, hurricanes and cyclones. As shown in Figure 8, reinforced steel corner pipes (81) are used, which are attached, using screws and wall plugs, on the wall or corner columns at the hole locations (82) on the external building corners (88) and then two pulling actions are applied. The first pulling action is carried out by tie rod (108) comprising a pressure chamber (1), steel cable (2), anchor (17), which is installed in the same fashion as in drilling (31). The second pulling action is horizontal and it is applied by two steel cables (84), one end thereof fixed on a steel ball (85) inserted into a modulated cross-section of the same shape (86) located onto the corner pipe (81) while the other end is fastened to a two-way traction screw (83); upon turning of said two-way traction screw (83) a horizontal traction is generated helping to unite the corner pipes (81) by applying a horizontal compression on the walls forcing them to become one with the structure (88). The joining of roof (88) with the corner pipes (81) is achieved by means of hole openings for the passage of steel cable (80), which are on the roof (90) steel framework, and are tightened together with the pressure chambers (1) through traction on steel cable (2).

(c) Floating underwater roads. In the prior art, bridges were constructed in order to get across from one coast to another, however, these are very costly as they require the construction of columns underwater and if the depth to which foundations will be laid is great, it is impossible to construct. Another way is by constructing underwater tunnels. This, too, is very costly due to boring at great depths. We therefore propose, as an alternative solution, the construction of an underwater floating road (Figure 10 (92)) operating like a submarine. This construction method has a number of advantages compared to the existing construction methods. First of all, it is cheap because it is built onshore; secondly, sea accidents will be avoided given that it is an underwater structure not posing any problems to navigation; thirdly, it may be constructed regardless of the sea bed depth and, fourthly, it is not affected by winds or earthquakes. Construction is carried out as follows: floating underwater roads are constructed onshore and then transported to the point of setting by floating cranes and barges and left on the sea surface (105) where they float by virtue of their sealed compartments, just like in submarines, i.e. sealed road surface (94) and sealed external chambers (95). When water inflow valve (100) is turned on, sea water flows into the sealed compartments and the floating underwater roads start sinking since their own weight is equated to that of the sea. When submerged to 20 m, the air inflow valve (102) and the water outflow valve (101) are turned on closing at the same time the water inflow valve (100). The air inflow valve (102) and the water outflow valve (101) are linked to the sea surface by means of two rubber pipes that terminate on a floating craft. Water is pumped out through valve (101) using a pump that is located at the other end of the rubber pipe, on the floating craft, while valve (102) supplies the air needed to maintain atmospheric pressure in the sealed chamber and enable the pumping system operation. Through the valve system, the floating underwater road can be raised or lowered balancing finally to the particular desired depth and then it is anchored using the hydraulic tie rod system (108) in shallow drillings (31) previously bored on the sea bed (106) by means of a small submarine. The procedure is repeated with the rest of the sections of the floating underwater road, joining them with bolts and nuts through the fastening holes on their frames. To improve the road surface water-tightness (93), a sealing rubber insert (97) is inserted between the frames of each section of the floating underwater road. When the joining and sealing procedure of all sections (92) of the floating underwater road is completed, all water is removed from the sealed compartments through valves (102) and (101) and the water pump located on the sea surface on a floating craft and then water is pumped away from the road surface (93). The lifting force generated on the floating underwater roads as a result of pumping out the water from the road surface (93) and the sealed compartments is the service load of the road (93). This lifting force of the floating underwater road towards sea surface (105) is counterbalanced by hydraulic tie rods (108) comprising pressure chamber (Figure 10, (I)), steel cable (2), anchor (17), lateral anchor blades (18), pressure chamber base (104) and steel cable guide (96). Still, inside the sealed compartments there is an extension of the sealed compartment water outflow pipe (107), which is an extension of the surface rubber tube and valve (101). The road is ready for use once the air equipment is installed and the road pavement is laid. Moreover, in order to protect the floating underwater road from sea currents, inclined side tie rods are installed at intervals on both sides of the floating underwater road. Said side ties rods are mounted on specially configured side mountings (103) on the floating underwater road.

All the aforementioned application examples for the hydraulic tie rod for construction projects of the present invention as well as any additional applications pertaining to the use of the hydraulic tie rod for construction projects of the present invention that may occur to those skilled in the art form part of the present invention and are deemed to be within the scope of protection thereof as set forth in the claims appended hereto.