Showing papers on "Caisson published in 1992"

Prestressed caisson bearing pier and structural foundation device.

Abstract: A bearing pier foundation for compacting soil that includes a plug extending along the longitudinal axis having a first section and a second section. The first section adapted to receive a pushing force for pushing the plug into the soil and the second section adapted to rest on the soil to be compacted. A plane, which is perpendicular to the longitudinal axis, passes through the second section. The second section includes a first part and a second part. The first part has an inner edge and an outer edge intersecting the plane. The outer edge of the first part attaches to the first section and is positioned further away from the longitudinal axis than the inner edge of the first part. The second part has an outer edge attached to the first part inner edge. The second part extends downwardly from the plane and the second part has a tapering segment extending along the longitudinal axis and includes an upper end and a lower end. The upper end is positioned closer to the plane and has a larger geometric diameter than the lower end. The segment continuously tapers from the upper end to the lower end. The bearing pier foundation can be used in connection with a sheath which conforms to the outer surface of the bearing pier foundation. Further, the bearing pier foundation can be used in combination with a hydraulic setting tool. Also, disclosed is a method for installing the plug and sheath into the soil to compress and consolidate the soil thereunder.

Large-scale loading tests of shallow footings in pneumatic caisson

Abstract: A series of large‐scale loading tests of square and rectangular footings on a naturally deposited dense scoria (a granular material produced by volcanic activities) was conducted in a pneumatic caisson. Standard penetration tests (SPTs) showed that the blow counts required for a 30‐cm penetration (TV‐value) were more than 70. This paper presents the method of the loading tests, characteristics of load‐settlement relations and failure mechanisms observed. The test results showed that bearing‐capacity factors decreased with increasing footing size. A set of stress characteristic equations incorporating stress dependency of angle of shearing resistance was solved numerically by use of the finite difference method to interpret the experimental data. Parameters required for the numerical computations were determined from the triaxial compression test data on an undisturbed sample. Good agreement was obtained between the numerical results and the experimental observations. A close examination of the failure mec...

Impact loading and dynamic response of caisson breakwaters

Abstract: The results of large-scale model tests on impact loading and dynamic response of a caisson breakwater are presented. Hydraulic model tests are performed in which the impact loading is induced by breaking waves on the structure. Horizontal impact forces, uplift forces and the related overturning moments are determined. The transmissibility of the impact loads and the accelerations of the structure are investigated (dynamic response).. The hydraulic model tests are supplemented by pendulum tests on the same caisson breakwater model used in the hydraulic model tests in order to determine the characteristics of the structural model itself. The added mass of water oscillating with the structure, the stiffness of the foundation and the damping ratio are evaluated from these tests.

Offshore double cone structure

Abstract: An offshore double cone structure for operation on an ocean foundation has a double-cone concrete shell having a neck ring at the top of the shell and a base caisson that supports the double-cone shell. The caisson rests on the ocean foundation. The environmental loads, topside weight, and self weight of the double-cone shell are transferred by double-cone shell action through the base caisson to the foundation. The base caisson's exterior wall can be either vertical or sloping. The neck ring is at an elevation sufficiently high that the wave and ice interactions with the neck ring do not increase global ice loads acting on the structure. The neck ring has sufficient area to provide room for facilities through the neck.

Device for sealing a caisson in a watertight way

Abstract: The invention relates to a device for sealing a caisson comprising a bottom, two upright side walls and a back wall, and intended for carrying out works to a sheet pile wall below the water line, characterized in that it comprises the combination of an inflatable continuous air chamber (8); a series of deformable sealing elements (9); a core (10) which can be displaced between each of said sealing elements (9) and the air chamber (8) and guiding plates (11) and means for allowing the lateral displacement of said sealing elements with respect to the caisson.

Ocean structure for shipment of general waste

Abstract: PURPOSE:To efficiently perform waste disposal by forming a soft bottoming style sea location type of a ocean structure for shipment of usual wastes of a caisson body having plural ballast parts and a shipment base for the wastes loaded in the caisson body CONSTITUTION:An ocean structure 1 for shipment of usual wastes is formed of a caisson body 3 having plural ballast parts 2 and a shipment base for usual wastes loaded in the caisson body 3 The wastes transported on land are moved into a hopper 5, and supplied to a compacter 7 by a feed device 6 The wastes supplied to the compacter 7 is compressedly reduced in volume by a hydraulic mechanism to be loaded into a container 11, which is carried to a gantry crane 9 by a container moving equipment 8, and shipped onto a waste container carrier 12 Thus the wastes can be efficiently transported on the sea

Foundation Reliability of Anchor Block for Suspension Bridge

Abstract: The suspension bridge across the eastern channel of Great Belt with a main span of 1624 m is part of the Great Belt Link in Denmark scheduled to be finished in 1997. A reliability study of foundation failure for the western anchor block has been performed in order to obtain quantified assessments of the reliability. The two different anchor block structures submitted for tender — Caisson and In-situ cast anchor blocks — have been investigated. The present paper describes the investigations carried out for the in-situ cast anchor block.

Setting method of caisson

Abstract: PURPOSE:To shorten the constructing period by injecting the air to buoyancy bodies mounted on side wall parts to surface a caisson, towing it to a set position, extracting the air from the buoyancy bodies to set the caisson, and supplying the remaining packing material into the caisson. CONSTITUTION:A required quantity of a packing material 4 is charged in the space part of a caisson formed of concrete, and a plurality of buoyancy bodies 7 laid into the air extracted state are mounted on side wall parts. Water is introduced to a caisson storage space in which the caisson 1 is set, and a compressed air is injected to the buoyancy bodies 7 to surface the caisson 1. Then, the caisson 1 is towed to a set position by a ship, the air in the buoyancy bodies 7 is extracted to set the caisson on the set position. The remaining packing material 4 such as earth and sand is supplied into the caisson 1, which is covered with a cap, and the work is completed. The setting work is thus efficiently performed, and the construction period can be shortened.

Foundation design, troll platform

Abstract: In 1979 the first gas was discovered at the Troll Field which turned out to be Europe's largest offshore gas field Different concepts of gravity base structure platforms have been analysed and evaluated over the past decade Special development projects have contributed significantly to the geotechnical design procedures A review of this development is given in the paper A tripod type of platform was studied during the first years However, increased confidence in the analyses of foundation stiffness resulted in a platform concept with a single caisson and a foundation of skirt piles (SP) The construction of the CONDEEP SP gravity base structure was started in September 1991 It will be installed in 1995 at the Troll East Field located in the Norwegian Trench in a water depth of 303 m The skirts will penetrate 36 m into soft clay The paper reviews geotechnical aspects of main concern in the development of a feasible concept and the design Dynamic effects of tall offshore structures on soft foundation soil have been of main concern in the project Requirements to foundation stiffness caused a somewhat bigger foundation than necessary to fulfil the requirements to platform stability A major effort was put into the determination of the cyclic soil parameters during the platform lifetime

Construction method for cut-off caisson

Abstract: PURPOSE:To form a dry space in an inside enclosed by a caisson by setting the caisson furnished with an opening section at the bottom surface, which coincides with a channel on riprup mound furnished with the channel connected to a rock mass, and thereby integrating both of them into one by means of concrete placing in water CONSTITUTION:A riprup mound 1 is first formed with a channel 2 by the use of a cut-off block 3 made of concrete, which is made up out of double wall panels faced to each other, and of a periphery plate In the second place, a cut-off zone 33 made of impermeable material is set by making use of a spacer consisting of the cut-off block 3 On the other hand, in constructing the caisson, an opening section is provided at a position which coincides with the channel 2 when the caisson is rested on a mound 1, the caisson is carefully lowered down therefore in such a way that both of them mutually coincide with, so that it is thereby rested on the mound 1 Following which, reinforcing bars are then placed while both of the channel 2 and the opening section are being penetrated through, and when concrete is placed in water until it reaches an under water rock mass, the mound 1 is completely integrated with the caisson, so that a cut-off wall is thereby formed

Heavy object transport carriage with direction changeable mechanism

Abstract: PURPOSE:To enable changeover of direction in a transport carriage loaded with a heavy object such as concrete caisson moved onto a launching platform by supporting a loading base supporting a jack for lifting the heavy object on a movable frame, and lifting the frame with a jack so as to turn it in the horizontal direction. CONSTITUTION:In a groove like passage 4a of a manufacturing base 4, a hydraulic jack 19 in the contracted condition is entered through a transverse feed track 3 and positioned under a caisson A. Hereat, the hydraulic jack 19 is extended, a dolly block 22 is pressed on the bottom face of the caisson A, and the caisson is lifted up. Nextly, a carriage 10 is run, moved to the crossing position with a longitudinal feed track 2, and once loaded on a temporary receiving base B. Nextly, a jack for lifting a frame is extended to lift the whole carriage and turned by 90 deg. with a cylinder for turning not shown in the figure. Nextly, the jack 30 is contracted to bring down the carriage, and the caisson A on the temporary receiving base B is loaded again and longitudinally fed.

Open caisson method

Abstract: PURPOSE:To facilitate underwater excavation over a long-term period and shorten construction period by excavating and lossening the ground at a submerged position of a caisson with an auger in advance, filling the earth and sand to be drilled with high water absorption resin, and stirring up and mixing them for the submerged installation of the caisson. CONSTITUTION:An island suited to water depth is constructed at the installation position of a caisson 1, and a submerged installation position is drilled with an auger for improvement of the ground in the form of loosening the ground. Next, an earth anchor 7 is installed and a H-shaped steel pile 9 for scaffolding is driven in, and a cutting edge hardware 10 of the caisson 1 is installed to construct the body of the caisson 1 on it. Moreover, the improved ground inside the body is excavated with a clamshell or the like, and a hydraulic jack 12 is operated for pressure-in and submerged installation of the caisson 1. The work for a bottom board 15 and a top board 16 is carried cut and after constructing a bridge pier 17, a water wall 14 is removed. It is thus possible to shorten the construction period of caisson 1 largely.

Vertical shaft excavator

Abstract: PURPOSE:To settle a caisson without requiring man-power and to mechanize in the case of construction of a vertical shaft by excavating downward of the caisson by a cutter, and tuning the earth into liquid or slurry with muddy water by pressure feed from a sludge delivery port to make it possible to discharge sludge from a sludge discharging port CONSTITUTION:Four openings 2 are formed on the bottom 1a of a caisson 1 settled into the ground, and pipes are respectively fixed to them Excavators 4 are respectively provided to those pipes 3, and ground 5 under the caisson l is excavated to have such constitution as the caisson 1 can be settled When the entire area downward of the bottom 1a of the caisson is excavated with widely opened cutters 15, 15, 15 and 15, the bottom 1a and a wall 1b are lowered by their dead weights, etc The earth from the excavation of the ground 5 is mixed with muddy water by pressure-feed from a sludge delivery port 24 to turn it into liquid or slurry, it is delivered to a muddy water treatment device 6 mentioned above from a sludge discharging port 26 through a connection port 27, etc, and a specific treatment is applied thereto to send it out by a dump truck

Construction of underground structure

Abstract: PURPOSE:To permit the frictional resistance of periphery to be reduced or increased by a method in which a pipe is inserted into a clearance between the upper side wall of a collar and the ground, a granular material is charged into the clearance, a structure is settled down, and while drawing the pipe, a solidifying material is injected from the lower end of the pipe. CONSTITUTION:When a caisson 1 consisting of side wall 11 and bottom plate 12, having a collar 13 projected toward the periphery of lower end, is settled down, while keeping a clearance 14 between the periphery of the side wall 11 and the ground 7, the caisson 1 is settled down, and an adequate number of double tubes 2 are inserted into the clearance 14 to charge granular material such as crushed stone aggregate 3 into the clearance. In settling the caisson 1 down, the outer tube 23 of the double cubes 2 is vibrated, the vibration is transmitted to the aggregate 3 to make the packed density of the aggregate 3 constant, whereby reducing the frictional resistance between the caisson 1 and the aggregate 3. After the caisson 1 is settled down to a given depth, while pulling out the outer tube 23, a solidifying material 5 is packed through the hole 21 of the inner tube 22 into the clearance 14 to increase the peripheral frictional resistance integrally with the ground 7.

Sealing construction for steel pipe adding caisson foundation

Abstract: PURPOSE:To seal a plumb joint on a steel pipe pile line for supporting a caisson, and keep its bearing force stably. CONSTITUTION:On steel pipe adding caisson foundation work for embedding a plurality of steel pipe piles 8 for supporting a caisson along the external side of the caisson 2, under ground, and constructing an underground continuous wall, along a plumb joint between the steel pipe piles embedded in ground, a hole 10 with a contour larger than a joint interval is bored through the external side of a steel pipe pile line. Into the hole, steel pipe joint sealing material 9 formed with a columnar skin with the main body of elastic material with the built-in injecting pipe of a filler is inserted, and the internal section of the skin is filled up with the filler, and the hole is closed, and the underground continuous wall is constructed.

Ocean structure for disposing of general waste

Abstract: PURPOSE:To make waste disposal more efficient by forming a soft bottoming style sea location type of a ocean structure for disposing usual wastes of a caisson body having plural ballast parts and an usual waste crushing and disposing facility provided in a body with the caisson body. CONSTITUTION:An ocean structure 1 for disposing usual wastes is formed of a caisson body 3 having plural ballast parts 2 and an usual waste crushing and disposing facility 4 provided in a body with the caisson body 3. Dust or a dust container 12 transported on the sea by a small-sized ship or a dust container ship 11 is unloaded from the ship brought alongside the terminal of the caisson body 3 by a gantgry crane, and carried to a dustpit 5 or a dust container pit 5a. A bulky refuse or the like crushed and selected by a crushing device 6, a selecting machine 7 and a iron element collecting device 8 are classified into such process as earth filling, incineration and iron element collection and disposed.

Assembly type simple caisson and landslide protection construction method

Abstract: PURPOSE:To effectively use a lot by jointing a plurality of caissons having freely detachable form panels outside and gap sections for filling landslide protection concrete, settling the caissons into the lot and filling the gap sections with landslide protection concrete. CONSTITUTION:A plurality of caissons 1 having freely detachable form panels 1b outside are jointed, and caisson wall bodies 2 are laid near the boundaries of the caissons 1. Edge form sections 1e are formed on the lowermost form panel 1b for facilitating the settlement of the caissons 1. Thereafter, sediments within the grounding section of the caisson wall bodies 2 are excavated, and the caisson unit 1 is pertinently added for settlement to the predetermined depth with the own weight thereof. In addition, gap sections 1c are filled with landslide protection concrete, and the form panels 1b are drawn out before the concrete cures. The aforesaid process is repeated and the caisson wall bodies 2 are combined to form a caisson A, and a landslide protection continuous wall is formed on the periphery thereof. According to the aforesaid construction, the space of the lot can be effectively used.

Joint structure of steel plate concrete board

Abstract: PURPOSE:To restrain cone-shaped shear fracture by depositing a T-shaped steel plate to a main reinforcing bar and a sub reinforcing bar of steel plate concrete board, and then one end of the T-shaped steel plate to a caisson steel partition wall of steel pate concrete. CONSTITUTION:The steel member joint structure of an exterior wall 8 formed out of reinforced concretes 9 and steel plates 10 is constituted by disposing T-shaped steel plate 14 at a gate consisting of a main reinforcing bar 12 and a sub reinforcing bar 13. The sub reinforcing bar 13 is piled up and fixed on the main reinforcing bar 12 to bend its center into a V shape to the steel plate 10 side. Besides, a flange part 14a is installed at the T-shaped steel plate 14 for deposit to the main reinforcing bar 12. The other end of it is deposited to a caisson partition wall 15 arranged perpendicularly to the facing surface of the steel plate 10. It is thus possible to make the sub reinforcing bar 13 restrain cone-shaped shear fracture and increase steel partition wall strength even if caisson inside is filled with earth and sand and pulling forth is given to the steel partition wall 15.

Method for joining caisson and support pipe in pneumatic caisson construction

Abstract: PURPOSE:To cope with a construction stress with a thin bottom plate by fitting steel members as composite members as a unit on the ceiling of a working chamber before settling the caisson and removing the steel members front the ceiling and arranging steel rods after settling the caisson. CONSTITUTION:A plurality of support piles are constructed in an expected ground of a caisson 1. Next, the caisson 1 previously fitted with long size steel members 3 by dowels 4 at the ceiling of the working chamber 14 or at the lower face of bottom slab 12. Compressed air is then applied in the working chamber 14 to sink the caisson 1 while excavating the ground. The caisson 1 is settled until the head of the support piles 2 is exposed in the working chamber 14 and the steel members 3 are removed from the bottom slab. Further, after reinforced rods are arranged between the support piles 2, concrete is placed in the working chamber 14.

Method for installing a device for protection against the swell, and device resulting from the implementation of this method

Abstract: The device comprises at least one support (2; 2'; 2''; 2''', 2'''') fixed to a predetermined site on a seabed, and a caisson (1; 1', 1'') comprising means allowing it to be floated so that it can be transported as far as the predetermined site, and means (12, 13; 7; 7') for raising the caisson onto the support so that the caisson is then at least partially submerged in a predetermined position with respect to the surface of the water. The caisson (1) is centred on the support (2'') by guides (13) interacting with spindles (12) secured to the support. It is made to bear on the support in a gravity fashion by the addition of ballast. Application to the protection of a coastal site or construction.

Method for constructing foundation of caisson

Abstract: PURPOSE:To facilitate execution of work by constructing the underfloor of the lowermost floor in the form of a caisson on the surface of ground, sinking the caisson to place concrete thereunder and forming the head of a cast-in-place concrete pile and the caisson integrally with a pressure bearing slab. CONSTITUTION:A pile hole 1 is formed under the ground level G and a reinforcement member 2 is put on the head of the pile and thereafter concrete is placed to construct a cast-in-place concrete pile 3. Next, a caisson 10 is constructed on the ground level G and the ground under the caisson 10 is excavated to sink the caisson 10, after which the body structure of the second basement, i.e. a column 20, beam 21, floor slab 22 of first basement and outside wall 23, is constructed on the ground and then the ground under the caisson 10 is excavated to sink the caisson so that a floor slab 22 of first basement reaches the ground level G and thereafter a floor slab 32 of the first floor reaches the level G, as shown in the figure. And sub-slab concrete 40 is placed to form a pressure bearing slab 41 in such a manner that the slab 41 is formed integrally with the top of pie 3, the edge 14 of the caisson 14 and the floor slab 12 of the caisson 10.

Process and device for ensuring a dry open air construction site on a bank

Abstract: The device according to the invention is a mobile device for ensuring a dryopen air construction site on a bank, which includes a caisson having atleast two openings situated in planes which between them form a dihedralangle, the first opening being provided to give access to the constructionsite on the bank, being fitted in a sealed way to the bank, by its peripheraledge, and the second opening being provided to give access inside thecaisson, from the open air above the level of the water.

Construction of caisson bottom slab

Abstract: PURPOSE:To raise the pressure resistance of bottom slab by a method in which a reinforcing bar cage having a horizontally expansible outer shape is set on the bottom of an open caisson, its outer shape is expanded to near the cutting edge of the caisson, and concrete is placed CONSTITUTION:An outer shell reinforcing bar cage 1 is formed by connecting a square ceiling plate 11 with a bottom slab 12 by a connecting reinforcing bar cage 13 A slide reinforcing bar cage 2a is set between the plate 11 and the slab 12 to make it expansible toward outside in the horizontal direction The reinforcing bar cage is hung down into the caisson side walls 3 and set on the bottom The cage 2a is slid outwards to expand its outer shape to near the inside of the caisson cutting edge 31, and concrete is placed and hardened The pressure resistance of any scale of caissons can thus exactly secured without needs to increase the setting length of the caisson

Foundation method for sky parking device

Abstract: PURPOSE:To facilitate pile driving work by forming a bottom section having a trench at the cutting edge of the caisson body constructed under the ground, driving concrete pile through the trench while guiding them by means of guide frame, and blockading the trench CONSTITUTION:A cylindrical caisson is buried under the ground to construct a caisson body K The caisson cutting edge K1a at the lowest section of this caisson body K is concreted to form the bottom section 1 In the next step, trenches 1a are provided on the four corners of this bottom section 1, and a guide frame 10 is assembled on the middle of the caisson body K In the next step, concrete piles 2 are driven by taking steel pipe piles as extension members through the through holes 1a of the bottom section 1 of the caisson body K, and the through holes 1a are blockaded by a base bottom plate 4 with the head of the piles arranged to the same level This constitution can facilitate pile driving work

Settle-down work of caisson

Abstract: PURPOSE:To raise the efficiency of caisson settle-down work by a method in which the ground is excavated in a trench form along the inner wall of caisson, the width of the trench is expanded toward the peripheral side, and the ground below the cutting edge of the caisson is excavated CONSTITUTION:A caisson 2 is set on a given position of the ground 1, and the ground is excavated in a trench form along the inner wall of the caisson 2 by using a kelley type excavator 3 A width-expanding driver 5 with a width- expanding blade 4 is attached to the upper part of the excavator 3 to excavate an expanded width portion 10 along the trench 9 The caisson 2 is settled down along the cutting edge of the caisson 2 When the settling down of the caisson 2 only by its own weight is impossible, a jack 8 is attached to the frame 7 to settle it down by the combined use of a pressing blade The excavation can be attained regardless of the size of the caisson, and the operation can be made with high efficiency by using small scale excavator for excavation only below the cutting blade

Execution method of joint material for caisson

Abstract: PURPOSE:To seal a joint completely, and to reduce cost by inserting a long-sized cylinder for filling a pressure fluid into a hollow long-sized cylinder, fixing the hollow long-sized cylinder to one sidewall of a caisson and injecting fillers into the hollow long-sized cylinder and the fluid into the long-sized cylinder respectively. CONSTITUTION:A long-sized cylinder 3 for filling a pressure fluid is inserted previously into a long-sized cylinder 2b for the secondary cut-off of a hollow long-sized cylinder 2. Two hollow long-sized cylinders 2, 2 are fixed onto the sidewalls of a caisson 5 at a space, the caisson 5 is sunk in the sea, and an adjacent caisson 5' is sunk at a specified joint space. Seawater is injected into a long-sized cylinder 2a for primary cut-off, the long-sized cylinder 2a is expanded, and concrete 9 is injected and filled. A conveying pump is driven and water is pressure-injected into a long-sized cylinder 3, the long-sized cylinder 3 is expanded and the outer surface of the long-sized cylinder 2b for secondary cut-off is contact-bonded with the sidewall 5a of the caisson 5'. The inside of a joint between the hollow long-sized cylinders 2, 2 is filled with an asphalt mastic, and the asphalt mastic is solidified, thus forming a water-impermeable layer 4.

Caisson settling work

Abstract: PURPOSE:To prevent the overmuch settling-down of a caisson as well as accelerate the settling of the caisson whose outer face is covered with a visco-elastic material layer of a small frictional force such as asphalt. CONSTITUTION:The ground under a caisson 1 is excavated in its excavating space 2, and the caisson 1 is settled down while accelerating the settling by the low frictional force of the visco-elastic material layer 3 of the outer wall 1b of the caisson 1. In the course of the settling, the temperature of the layer 3 is adequately changed by a temperature regulator 4 to regulate the change in the viscosity and frictional resistance of the layer 3. While controlling the settling speed of the caisson 1, the settling is accelerated and overmuch settling is prevented.