Diaphragm/ sea retaining wall system

Abstract

Diaphragm Sea/Retaining Wall System consists of retaining wall that spans horizontally between Deep Beam Diaphragms anchored into bedrock through rock socketed caissons. Deep beam Diaphragm is built of two round column sections that serve as vertical chords of the Diaphragm or as flanges of the Deep beam, and of the concrete web section continuously connected to both round columns. Fixity of the Deep Beam Diaphragm at the bedrock level is provided by embedment of two round column flanges of the Diaphragm into the predrilled rock sockets or caissons. Stiffness of the Deep Beam Diaphragm support and retaining wall reinforcement arrangement allows better force distribution between system elements and makes the system of present invention a most economical solution for difficult geotechnical conditions where large forces of static and dynamic nature has to be efficiently resisted by a retaining wall system. The present invention system is also the most reliable force resisting system for dynamic sign changing loads. The system can effectively resist seismic and static loads as well as large forces of wave action, and can be used for Ocean shore protection. Unique steel pipe concrete cast forms of the present invention and sequence of construction allow quick and efficient installation of the system in the most difficult conditions where top of bedrock elevation can significantly vary along the retaining wall length.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention provides innovative design and technique for construction of the earth retaining structure that can be utilized in a Sea Wall construction. The object of this invention is to create a modular Diaphragm Concrete Retaining Wall that can be easily constructed in the field using this unconventional approach.

The suggested-invention consists of two parallel lines of columns connected by stiffened concrete walls that form Diaphragms, and of continuous retaining wall running perpendicular to the Diaphragms. Each two columns of the parallel column lines are continuously connected to the stiffened concrete web wall forming Deep Beam, or Diaphragm assembly. Deep Beam or Diaphragm assembly cantilevers from the two predrilled caissons socketed into the bedrock. Concrete retaining wall spans horizontally between Deep Beam Diaphragms. Concrete columns or chords of the Diaphragm assembly are cast as a continuation of the caissons that provide fixity for the whole Diaphragm assembly. Horizontal stiffener ribs at the top and bottom of the Diaphragm serve as horizontal struts that transfer the load of the wave action and the load of active soil wedge and of seismic force to the top of the caisson where that force is reacted by caisson lateral elastic foundation and by the reactive couple created by two caissons tension-compression capacity.

Horizontal force and a moment couple are resisted by each set of two caissons that work as a beam on elastic foundation and as a tension or compression piles of the reaction couple. Depth and diameter of the caisson is dependent on the magnitude of the horizontal force and magnitude of the vertical force of the moment couple.

2. Description of the Prior Art

The Buttress Walls that were designed for a similar task were sequentially patented in 1908, 1909 and 1911. All three prior inventions being visually similar to present invention have significant philosophical and technical differences that make them badly suited for tasks of present invention. The present invention also has very unique construction sequence that makes it easier to construct. The following is the description of the prior Art and its claims

• • U.S. Pat. No. 938,091 Inventor: Maxwell M. Upsox
  • Issued: Mar. 10, 1909
  • U.S. Pat. No. 982,698 Inventor: Maxwell M. Upsox
  • Issued: Jan, 24, 1911

U.S. Pat. No. 982,698 is a slight and better modification of U.S. Pat. No. 938,091 therefore only U.S. Pat. No. 982,698 is described below

The object of the invention was to provide a wall consisting of combination of concrete vertical wall which is reinforced and is attached to and rigidly supported by a series of wing walls. Retaining part of the wall is directly supported and connected to piles. Ends of the wing walls are also supported and directly attached to the back piles. The retaining wall itself is reinforced by a series of horizontal and vertical bars placed close to exterior surface of the wall.

• • U.S. Pat. No. 905,771 Inventor: Maxwell M. Upsox
  • Issued: Dec. 1, 1908

The object of the invention was to provide a wall consisting of combination of concrete piling and curtain walls of sheet piling formed of wood, concrete or any other suitable material. Concrete piling consists of a series of concrete piles in pairs in two parallel rows. These piles are cast on land and placed in position within steel incased holes driven in the ground. Than a buttress wall formed between two piles in parallel rows. Buttress wall is connected to the piles through the eye -bolts and diagonal tie rods. The retaining wall proper is arranged between the buttresses and consist of sheet piling being driven into the ground with a penetration sufficient to take the horizontal thrust at the base of the piling. The horizontal beam or wale placed at the top of the wall in order to transfer the load of horizontal thrust into the buttresses.

SUMMARY OF PRESENT INVENTION

The present invention addresses the issues that were neglected or not well understood by prior inventor.

The present invention is a Diaphragm retaining structure that comprises two sets of parallel cast in place columns 11 with their rebar cages 20 embedded into the rock socketed caissons 17. Two round columns are continuously connected with precast or cast in place diaphragm 13 and together form a Deep Beam fixed at elevation slightly below the bedrock level. Web of the deep beam, or plate of the diaphragm is continuously connected to the columns through the special reinforcement loop connection details that provide horizontal tension and vertical shear capacity of the diaphragm web to chord (column) connection. Web of the diaphragm can be a cast in place unit or precast unit that connects to the diaphragm chord (round column) within specially allocated closure pours 15.

Retaining wall 14 is constructed of precast wall units or from the cast in place detail that runs perpendicular to the diaphragm units. Diaphragm units are designed to provide rigid support for retaining wall that spans horizontally between them. Rigidity of the diaphragm unit support and special retaining wall connection detail within closure pour 16 allows wall multi span continuity that brings 25% reduction in the wall negative moment and close to 50% reduction in the span positive moment. One of the benefits of that solution is not only moment reduction due to wall continuity over the diaphragm supports but the economy in the horizontal reinforcement placement along the height of the wall where larger area of steel may be placed in exact location.

A primary object of the present invention is to create a set of multiple fixed rigid diaphragm supports along the body of the retaining structure that allows retaining wall to span in a horizontal rather than in vertical direction and allows to take advantage of wall continuity over the set of rigid supports. That arrangement also allows the use of the system for loads with sign changing applications.

That horizontal span solution along with the usage of rigid deep beam diaphragm allows the present invention to overcome the shortcomings of the prior art devices previously used by industry.

Another, primary objective of the present invention is to create a system that can effectively use repetitive steps and limited number of reusable forms that do not require a mass production.

And still further objective of the present invention is to create the effective mechanism for Deep Beam (Diaphragm) fixity by anchoring the column (chord) vertical reinforcement in the rock socketed caissons.

Additional objectives of the present invention will appear as the description of the invention proceeds.

To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, the following description of the present invention and in the description of the construction sequence.

Attention, however, being called to the fact that the drawings are illustrative only, and that changes may possibly be required in any specific construction that illustrated and described within the scope of the appended claims.

The foregoing and other objects and advantages will appear from the description to follow. In the description all references are made to the accompanying drawings, which form a part hereof, and which illustrate specific embodiment where the invention may be practiced.

That embodiment is described in sufficient detail to enable those skilled in the art to practice the invention. It is also shall be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of invention. In the accompanying drawings, alike reference characters designate the same parts throughout all views. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims.

The present invention overcomes the shortcomings of the prior art by providing very stiff Diaphragm or cantilevered Deep Beam support (FIG. 1 and FIG. 2) for multi span retaining wall shown in FIG. 2

DESCRIPTION OF MAJOR PHYLASOPHICAL DIFFRENCES OF PRIOR ART AND OF PRESENT INVENTION

U.S. Pat. No. 938,091 vs. Present Invention:

1. The buttress wall of the prior art, namely U.S. Pat. No. 938,091, is connected to the front and back piles of the wall in such a manner that two piles directly share the load of the horizontal thrust and stiffness or moment of inertia of the so called buttress wall is equal to the sum of stiffnesses of each pile. The vertical shear capacity of the web to pile connection is limited to shear capacity of the two eye bolts that is absolutely negligent.

The present invention has substantially larger stiffness due to the fact that the web of the diaphragm is positively connected to the pile chords of the diaphragm through special dowel loop connections. The moment of inertia of such diaphragm is determined similarly to moment of inertia of the wide flange beam.

2. The retaining wall of the prior art, namely U.S. Pat. No. 938,091, spans in vertical direction and transfers the load of horizontal thrust at the top of the front wall and along the sheet pile embedment length.

The present invention has the retaining wall that continuously spans between rigid Deep Beam Diaphragm supports, and by virtue of that can take reversible load application with much greater efficiency. Stiffness of such support does not depend on parameters of soil backfill behind the wall.

U.S. Pat. No. 982,698 vs. Present Invention:

1. The buttress wall of the prior art, namely U.S. Pat. No. 982,698, has a triangular shape and is designed more like a stiffener that in combination with a front retaining wall creates a T-section of variable stiffness. The buttress is positively connected to the retaining wall, however, it is evident that T-section has much smaller moment of inertia than the Deep Beam Diaphragm section of the present invention, particularly in the top region of the wall. In addition, the variable stiffness of the T-section makes it an ill suited solution for seismic load application where resultant of the horizontal thrust shifts towards the top of the wall. The same observation will be true for large wave loads that become a significant design factor in Sea Wall applications.

The present invention has a cantilevered Deep Beam Diaphragm support of constant stiffness that is substantially stiffer than the buttress wall of the prior art. Higher stiffness of the support allows designer to use wall continuity approach. Such wall continuity approach is impossible to use with soft wall supports.

2. The retaining wall of the prior art, namely U.S. Pat. No. 982,698, spans horizontally and is designed as a simple span. Such approach makes that wall very uneconomical.

The present invention has a retaining wall that continuously spans between rigid Diaphragm supports, and by virtue of that can take reversible load application with much greater efficiency. The present invention can efficiently save close to 50% in wall reinforcement.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Features and advantages of the present invention will become more fully appreciated and understood when reviewed in conjunction with accompanying drawings. All drawings have similar parts referenced by alike characters in all details and views.

FIG. 1 Diaphragm Sea/Retaining Wall

FIG. 2 Section A-A. Diaphragm Sea/Retaining Wall

FIG. 3 Section B-B

FIG. 4 Shaft Cage Installation

FIG. 5 Section C-C. Column Form and Cage Installation

FIG. 6 Section D-D.

FIG. 7 Plan. Cast-In-Place Columns

FIG. 8 Lifting Device

DESCRIPTION OF THE REFERENCED NUMERALS

The numerals characters shown in different views that are illustrated in different Figures denote similar elements of the Diaphragm Sea/Retaining Wall that was selected for illustrative purposes of present invention application. The following numbering is used throughout the various drawing Figures.

• • 10. Diaphragm Sea/Retaining Wall
  • 11. front column of the Diaphragm
  • 12. back column of the Diaphragm
  • 13. web of the Diaphragm
  • 14. continuous retaining wall
  • 15. Diaphragm web closure pour.
  • 16. retaining wall closure pour
  • 17. caisson
  • 18. wall drainage system
  • 19. Styrofoam rebar spacer
  • 20. shaft cage
  • 21. retaining wall splice rebar
  • 22. diaphragm web splice rebar
  • 23. face section of the front column form.
  • 24. back section of the front column form.
  • 25. section of the back column form.
  • 26. adjustable form clamp
  • 27. Lifting Device with mechanical thread for machine bolts 28
  • 28. ¾″ dia. Erection bolts
  • 29. ¾″ dia.×3″ long Machine bolt
  • 30. bracket for Styrofoam spacer retainer
  • 31. Styrofoam retainer plate

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a new method of construction and installation of Sea or Retaining Walls. It also relates to improved design of Buttress Retaining Wall System. The following discussion describes in detail one embodiment of invention. This discussion, however, should not be construed, as limiting the invention to this particular embodiment. Practitioners skilled in the art will recognize other numerous embodiments as well. The drawings show similar elements of the invention denoted by the same numerical character in all views and sections shown in FIG. 1 through FIG. 8 where the present invention generally depicted by the numeral 10.

FIG. 1 shows vertical section of the Diaphragm Sea/Retaining wall.

FIG. 2 is an illustrative view of the Diaphragm Sea/Retaining Wall in plan. The wall in that plan is shown continuously run between Deep Beam Diaphragm supports. Continuity of the wall over support is provided by a special reinforcement loop details that is shown in FIG. 2.

FIG. 2 shows specially placed closure pour details 16 where column dowels 21 are spliced with U-shaped rebars of the wall. That arrangement was developed for wall precast option. However, the very same detail applies to wall cast in place option as well. Similar closure pour detail 15 was developed for Diaphragm web connection to the columns 11 and 12 where specially bent column dowels 22 are spliced with U-shaped rebars of the Diaphragm web 13.

FIG. 3 shows section through the Diaphragm stiffened web 13.

It shall be noted that stiffening haunches at the top and bottom of the Diaphragm web shall be stopped at the face of the closure pour 16.

Unstiffened diaphragm web closure pour 16 allows higher ductility level in case of dynamically imposed load of seismic event.

FIG. 4 shows shaft cage installation. Shaft cage 20 is installed in a predrilled shaft of the caisson. It shall be noted that the diameter of the caisson shall be at least 6″ larger than the diameter of the column above. Cage 20 of the shaft shall be installed plumb and must be centered on the shaft 17 center line. At the conclusion of the cage installation caisson shaft 17 is filled with concrete or grout just slightly above the bedrock level. Top of the caisson concrete pour is leveled for installation of column forms 23, 24 and 25. At that stage additional short steel pipe shear key device can be installed at the interface of the caisson and column, within the rebar cage, if cage rebars do not provide adequate horizontal shear resistance at that interface. In the next step preassembled column form assemblies are installed over the top of the column cage. FIG. 5 shows details of that installation.

FIG. 5 shows installation of front column 11 steel cast forms 23 and 24 and installation of back column 12 steel cast forms 25. Preassembled column forms are installed over the front and back column cages. Sections of the form are clamped together with adjustable form clamps 26 and held apart at specified distance by using Styrofoam rebar spacers 19. The whole form assembly is lifted in place by using special lifting device shown in FIG. 8 FIG. 5 also shows installation of column closure pour dowels 21 and 22.

FIG. 6 shows installation of column dowels 21 and 22. It shall be noted that Styrofoam rebar spacers 19 also serve as a closure of the column form that prevents escape of concrete during concrete pour operation. Sequence of column construction assumes a sufficient gap in Styrofoam spacer 19 to allow flexible pipe for concrete pump operation. Metal forms 23, 24 and 25 shall have horizontal short slotted holes at attachment of lifting device 27 to allow loosening of the form for a quick stripping of the whole form assembly.

FIG. 7 shows front and back columns 11 and 12 stripped of the metal cast forms. In the next step Diaphragm wall 13 is connected to the front and back columns. At the conclusion of the Diaphragm Sea Wall construction retaining wall 14 is connected to the front columns through the wall closure pour details 16 in case of precast wall option or through the similar detail for cast in place wall option.

While certain novel features of this invention have been shown and described in the annexed claims, it is not intended to be limited to the details above, since it shall be understood that various omissions, modifications and changes to the details of the device illustrated can be made by those skilled in the art without departing in any way from the idea of the present invention.

Claims

1. Diaphragm Retaining Wall system that comprises Deep Beam Diaphragm anchored into the bedrock through the front and back caissons, and front retaining wall that continuously spans between two adjacent Diaphragms, substantially as shown in FIG. 2

2. Deep Beam Diaphragm consisting of two round concrete columns anchored into the bedrock through the caisson sockets and concrete stiffened web plate continuously connected to each round column as described in FIG. 2

3. Continuity connection detail of the front retaining wall, and Diaphragm web connection detail, substantially as described in FIG. 2

4. Steel forms for Cast In Place column production and form lifting device, substantially as described in FIG. 4, 5 and FIG. 8