Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D29/00—Independent underground or underwater structures; Retaining walls
  • E02D29/02—Retaining or protecting walls
  • E02D29/0225—Retaining or protecting walls comprising retention means in the backfill
  • E02D29/0241—Retaining or protecting walls comprising retention means in the backfill the retention means being reinforced earth elements
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D29/00—Independent underground or underwater structures; Retaining walls
  • E02D29/02—Retaining or protecting walls
  • E02D29/0258—Retaining or protecting walls characterised by constructional features
  • E02D29/0266—Retaining or protecting walls characterised by constructional features made up of preformed elements

Definitions

• the retaining structures better known as. WALLS name 'OF RETAINING belong to the category of the oldest constructive tions made by man.
• Greco-Roman antiquity is a testimony to the beautiful achievements of the genre.
• retaining structures are made with one or more of the following materials: stone, wood, concrete, metal and of course the earth.
• ends (2) fixed to the anchor plates (3) will resist by the shearing of the earth mass.
• ends (2) were without an anchoring plate while having a sufficient length, they would provide stability by friction between the earth and the cable.
• the cable described above and shown in Figure 1 can be considered as a flat retaining structure.
• the type of structure proposed can be classified in the category of structures with metallic structure, characterized by the fact that stability is ensured by collaboration " T. ⁇ tre the mass to be retained and the structural elements.
• a DC element (fig. 2) is characterized by its curved central part (1) and by the two straight ends (2).
• the ends of the straight ends can be provided with or without anchoring plates (3).
• the DC elements defined in Figure 2 and juxtaposed according to Figure 3 represent the structure of the retaining structures.
• the backfilling by successive layers allows us to realize the association between the DC elements and the Earth. This is how the type of retaining structure proposed is carried out (fig. 4) "
• the backfill is a local material that is found on site with all the grain sizes, from the mainstream, passing through the granular to the clay soil. Any material that can produce high friction on DC elements is suitable; that which has a high resistance to shearing is also suitable as well as any material which makes it possible to avoid the possibility of a development of pore pressures inside the structure, This precludes a priori the use of soils with a large percentage of clay or even clay.
• the backfill must be free of organic matter and must meet certain electrochemical conditions vis-à-vis the corrosion of DC elements. Generally, the backfill should be chemically stable.
• the main structural element of the structure the DC element (fig. 2 and 3) must be manufactured in the factory from materials which have a high tensile strength and other characteristics pre-established by the conditions architectural .environment, the destination of the work and of course the quality of the embankment.
• DC elements can be with or without anchor plates.
• the choices of the geometry and the thickness of the DC elements result from the calculation of the local stability and of the overall stability, so as to minimize the cost of the construction of the structure.
• the geometric characteristics as well as the thickness of the DC elements may vary on the height of the structure.
• the durability of the works depends essentially on the resistance of the structural elements to the phenomenon of corrosion.
• the rate of corrosion of DC elements is linked to the nature of the materials buried and the characteristics of the soil.
• DC elements The choice of materials for DC elements, or for their protection, must be made according to the pH of the pore water and the resistivity of the fill material. We can consider a priori that non-clay granular materials, as defined for roads, are compatible with all materials for DC elements. In some cases, to prevent the corrosion phenomenon, DC elements can be protected by the application of paint layers based on bitumen, epoxy, etc ... provided that sufficient anchoring is ensured.
• the main materials considered for the manufacture of DC elements are: galvanized steel or not, stainless steel, cor-ten steel, aluminum alloys, plastic materials, composite materials, steel or plastic mesh .
• the DC elements can be in a single unit or in several components, multi-plates assembled on site by bolting (fig. 5 and 6).
• the assembly can be made waterproof or not.
• DC elements used as the structure of the proposed structure, are characterized by their stress in pure traction, an anchorage developed through friction (shear) with the embankment, as well as good durability.
• a DC element can be produced from a single quality of material or from several provided that there is electrochemical compatibility between the components.
• the DC elements can be the only structural elements of the structure where they can be associated with horizontal armatures made with metal trellis, textile membranes, etc.
• the anchor plates (3) can be metallic or precast concrete. Structures made with DC elements (fig. 4) lend themselves well to receiving on the facing a coating of precast concrete elements, bricks and above all shotcrete.
• DC elements can be used in combination with bolted anchors in the rock mass.
• the DC elements are freestanding during construction and deformable after the completion of the structure being able to follow the deformations of the foundation terrain.
• the foundation surface must be horizontal " . In well-defined cases, it can be tilted and even below the water level.
• the DC elements can be put out of use by breakage or tearing caused by too great a pulling force in the facing (l), or by the tearing of the part embedded in the solid mass ( 2).
• Geometric characteristics of the DC element (fig.7) as well as the essential elements for the sizing of the structure (fig.8) are: H the height of the DC element B. the width of the DC element
• planar sliding surface (Coulomb)
• thrust of the earth applied on the reference plane friction between the embankment and the elements DC equal to 1 angle of friction internal.
• the thrust of the land, vertical or horizontal is constant on a horizontal plane, but varies linearly with the depth (fig. 9).
• the lines M 'M''and Ml M2 can be considered at the same time as the intersection of a horizontal plane respectively vertical with the reference plane.
• the horizontal thrust Pz is considered constant over the height ⁇ H, as shown in FIG. 10.
• the embedding plan being an extension of the facing must be able to transmit the stresses to the mass of the embankment by friction or by shearing. At each point of contact of the part embedded in the earth, it must be ensured that the friction (shearing) actually exists
• a single thickness corresponding to equation 20 will be used for the entire height, or sometimes it may be economical to vary the thickness by length of height.
• the height ⁇ e of the structure H is a basic data
• Ce ⁇ pendant B has an optimal limit determined by the length of the embedding plane. For its choice, it will be necessary to take into account the possibilities of production, transport and especially
• the installation plan is a logical extension of the facing.
• the effort developed in the facing will be transmitted to the earth mass by the embedding plan.
• the embedding plan must be able, on the one hand, to take up all of the tractive effort transmitted by the facing and, on the other hand, to transmit the stresses to the earth mass without disorder. friction or shearing.
• e embedding plan must ensure by its length, the stability of the entire structure: tearing, pouring, sliding. a) Condition of non-wrenching. The state of the constraints between the earth mass and the embedding plan has been shown before. To determine the total tear resistance length La, you will have to follow the path of figure 15-
• the safety factor t for lifting Tj 0 may be different over the height of the structure if this is justified.
• the overturning phenomenon for structures with DC elements can occur by the overflow of the upper part of the structure when the length of the installation surface is insufficient.
• the safety coefficients for the DC elements working in tension as well as for their embedding will be established according to: the nature of the materials for the DC elements (more or less brittle materials), the nature of the backfilling materials (the certainty of a minimum coefficient of friction, the type of structure (permanent or temporary), the risk (the extent of the damage in the event of destruction), the risk of corrosion.
• the safety coefficients for overall stability will be determined from the: type of structure (permanent or temporary), risk (the extent of damage in the event of destruction). Generally, they cannot be lower than 1.5 for stability to overturning and sliding and 2- for the punching of the foundation.
• the facing will consist of semi-circular DC elements, made of mild steel with an admissible resistance of approximately 150 MPa.
• the backfill is provided in granular equivalent to those approved for roads.
• the following values have been adopted: the specific weight of the embankment of 18 kN
• the effective thickness "t" of the DC element is determined by the resistance conditions, being directly proportional to the width "B" and the height "H” of the DC element. We can follow the variation of the thickness "t” in fig. 18, 19, 0
• the length of the embedding plane "L” is generally determined by the condition of not being torn off.
• e represents the thickness of the entire DC element in relation to the length of the rectilinear front of the structure, thus: eo the thickness net without excess thickness for corrosion, and the net thickness plus an additional thickness of 0.5 mm for each face, e2 the net thickness plus an additional thickness of 1.0 mm for each face.
• the thickness of the DC elements is determined for the maximum sol ⁇ licitation either at the base of the structure and is kept constant over the entire height.
• the multipla DC elements are connected to a single encasing sheet of appropriate thickness.
• the embankment is assumed to be horizontal at the top and the foundation of the structure is considered to be horizontal and stable.
• the types of structures proposed according to their nature are retaining or retaining structures.
• the facing of structures taking into account the coating possibilities, may take the form and the color. In height, the facing can be vertical, inclined or on the terrace.
• Structures with a DC element structure can be erected as watertight or not, temporary or permanent retaining structures.
• the structures 35 can easily follow the movements of the foundation ground.
• the realization of temporary works becomes very interesting, by the speed of execution, by the ease of demolition and recovery . total of DC elements.
• the type of structure proposed is very flexible for landscaping terraced accommodation for housing or agriculture.
• Retaining structures with structure in DC 5 elements can receive very large overloads and lend themselves to the construction of retaining walls for communication routes, bridge abutments, etc.
• the mass to be retained may not be earth, but many mineral, industrial or vegetable products, with the aim of increasing c.ooaéiîdérably the stocks.
• the communication routes involve earthworks. awe-inspiring relief which brings about the need for various elements retaining elements. These can be created using DC element structures. This can range from the retaining wall to the abutment of engineering structures.
• the facing can receive a sprayed concrete coating or a veneer of decorative elements of pre-fabricated concrete.
• the DC elements with double facing have deformable cells which can absorb the shock of vehicles in the event of an accident.
• Islands - offshore platforms 20 On a body of water, artificial islands or peninsulas can be made for recreation, ice control, industry, etc. The execution can be carried out dry or under the water level.
• An off-shore platform is an artificial island made in shallow water for explorations.
• a combination of short metal piles and DC elements can be realized.
• Backfilling can be done by dredging.
• a tank dug in the ground can be produced using DC elements.
• the debris is to be deposited around the excavation; thus, the reservoir created is partly raised above the natural terrain
• DC elements whose facings are semi-circular, elliptical or other, their assemblies are made of ma-. 35 ni ⁇ re waterproof. When the facings are provided with connectors, these can be the same as the first ones. The facing thus produced has a more aesthetic appearance of continuity.
• the "embedding-connection plan" nodes can. be_assembled either in the factory or on a site. Once these knots are in place, the central part of the facing can be fixed.
• the bottom of the tanks consists of a waterproof layer supplemented if necessary by a synthetic membrane. 5
• a trellis fixed on the various joining elements allows the production of a sprayed concrete covering.
• the latter can be smooth or covered with any other finish. tion such as ceramic.
• the range of ponds can be of a wide variety and 10 can be used for municipal, industrial or agricultural purposes.
• the DC structures by their design allow us to realize buried tank tanks. Even when they are partially on the surface, the mass of the earth around the reservoir is large enough that one can consider that they are buried. Therefore, this type of tank offers a very large operating safety, completely eliminating the safety bowl and the drawbacks which. 25 ..
• the tanks made with DC structures can be erected on a deformable foundation ground. These deformations do not affect the vertical part, the bottom and the flexible walls must be compatible with rigid roofs. 30
• 35 DC tank tanks can be used to store: petroleum products and their derivatives, chemicals, drinking water and miscellaneous.
• the roof of DC tank tanks will be of conventional type rigid or flexible, exposed, floating or covered with soil. It will be supported or anchored on a reinforced concrete belt made at the top of the DC structure (the wall). For large capacity tanks, a central support tower for the roof is recommended. Intermediate support can be envisaged.
• the structure of the roof can be made of: prestressed precast concrete, metal boxes, domes, structure on cables, inflatable structure, floating structure. Hydro installations
• the volume of materials can be substantially reduced. If there is a lot of traffic on the crowning, large traffic lanes can be made without a significant increase in the fill.
• the sample screen On a permeable foundation, the sample screen can be extended in depth using a mud trench.
• the structures in DC elements do not fear settlements.
• the backfilling is very simple and quick to perform compared to an area structure.
• An overflow opening can be produced without problems for stabilization. of the whole structure.
• Spillways or spillways can be made for minor hydro developments serving as storage for irrigation purposes or the establishment of micro-hydroelectric plants.

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• Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Paleontology (AREA)
• Civil Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Revetment (AREA)
• Shaping Of Tube Ends By Bending Or Straightening (AREA)
• Manipulator (AREA)
• Pit Excavations, Shoring, Fill Or Stabilisation Of Slopes (AREA)
• Materials For Medical Uses (AREA)
• Apparatus For Radiation Diagnosis (AREA)
• Absorbent Articles And Supports Therefor (AREA)
• Prostheses (AREA)
• Bridges Or Land Bridges (AREA)
• Roof Covering Using Slabs Or Stiff Sheets (AREA)
• Forms Removed On Construction Sites Or Auxiliary Members Thereof (AREA)

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• 1984
  • 1984-06-26 FR FR8410066A patent/FR2566442B1/fr not_active Expired
• 1985
  • 1985-06-06 DE DE8585902574T patent/DE3585215D1/de not_active Expired - Lifetime
  • 1985-06-06 AU AU44065/85A patent/AU4406585A/en not_active Abandoned
  • 1985-06-06 WO PCT/FR1985/000142 patent/WO1986000354A1/fr not_active Ceased
  • 1985-06-06 EP EP85902574A patent/EP0185041B1/de not_active Expired - Lifetime
  • 1985-06-06 AT AT85902574T patent/ATE71681T1/de active

Non-Patent Citations (1)

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