GB2184472A - Method of crib-log wall construction - Google Patents

Abstract

A diagonal form of crib-log wall constructed from identical preformed units 1,3 assembled with pivoting joints 2 in a manner which allows the wall to be constructed at any inclination of slope, or with a change of inclination at any height up the slope; and by varying the lengths of some units, horizontal curves or angles are formed in the wall. Methods are provided whereby the said crib-log wall incorporates reinforcing supports under the wall, or slope reinforcement within filling material supported by the wall. <IMAGE>

Description

SPECIFICATION Method of wall construction This invention relates to a method of wall construction forthe support, retention orreinforcementofsloping ground.

Steeply sloping ground often requires support by means of some type of wall. Various types of walls are well known, most of which are vertical or nearly vertical. One such type of nearly vertical wall is a crib-log wall with a slope usually of 4vertical increments to 1 similar horizontal increment. This slope is normally kept constantforthe full height of the wall. This known type of crib-log wall is constructed from several different precast or pre-formed units which are assembled in rectangularform to create a structural entity.

The present invention is a crib-log type of wall in that it comprises pre-formed units which by means of a new method of assembly, can adequately support or reinforce sloping ground at any angle in a manner which can prevent slipping or movement ofthe ground. Only one type of unit is needed for the construction ofthe wall. This type of wall can be easily and quickly constructed with adequate strength and attractive appearance. A novel feature ofthe invention is the assembly of the pre-formed units into a diagonal pattern as viewed from above. The construction forms a sloping wall which can em body: (1 ) a change (or changes) in the slope angle ofthe wall at any pre-determined height on the wall face.

(2) horizontal curves in the wall face, as viewed from above, (3) horizontal angular changes, either external or re-entrant, as viewed from above.

For straight slopes the wall is constructed with a multiplicity of identical pre-formed units. In this form of wall there can be variations in the slope angle in the vertical plane. To construct curves or angles in the horizontal plane some units must have a different length, but are ofthesame shape as all otherunits.

The method of constructing the wall includes the assembly ofthe basic units, all ofthe same length,toform horizontal courses or layers. In each layerthe units are pivotally connected attheirends each to the nextand set in a multiple V pattern. Each subsequent upper layerisdisplaced into the slope by an amountdetermined by the width of each layer. The angle between two adjacent members determines this width which can be fixed rigidly by a unit connecting each front V point of a layerto each back V point ofthe next layer above.This connecting u nit may be the sa me length as the basic u n its or it may be of different length.The succesion of layers is constructed with each layer displaced horizontally into the slope so that the front of each upper layer is pivotally connected to the back of each layer below the said upper layer. The pivotal connections between all adjacent members is a novel aspect of this present invention as itallowsthe horizontal angle between adjacent members of a layerto be adjusted to any required anglethatsuits the angle ofthe slope in the vertical plane. After construction of the wall or during construction, the pivotal connections can be made rigid in some forms ofthis method of construction and thus create a rigidly interconnected structure ofgreat strength.

The pre-formed units may be of any suitable material and preferably would be of precastconcrete, ferro-cement, or fibre reinforced concrete, all of which have known properties; or natural timbersuitably treated to resist rotting in the ground. The pivotal connections may be formed in any mannerto allowthe horizontal angles between adjacent units to be changed, but preferably are made in the precast concrete units by forming the base surface and upper surface at the ends of a unit, where connecting with units above and below, as hemispherical shapes or as cylindrical cone shapes, to match the upper and lower units. In addition the ends are of cylindrical shape with a central holethrough which is inserted a central rod preferably of steel orothersuitable material.Any remaining space around the rod in the hole formed inthe ends of the units may be filled with a suitablefilling material which is preferably concrete mortar. Bythis means all the vertical joints are rigidlyjoined during orafterassembly of the wall. Fortimberunitsthe connection between vertically and horizontally adjacent units is made with a suitable rod, preferably of steel, passing through holes bored vertically through the ends of the timber units.

Byway of example, a preferred embodiment of the present invention is described in detail with reference to the following drawings in which:- Figure lisa perspective view of part of an assembled crib-log wall constructed in accordance with one aspect of the method ofthe present invention. In general the units may be of any suitable material.

Figure2 is a cross section of the said wall showing the step formation of the front face and the successive layers from layer 1 at the bottom to layer 5 atthetop, in this example.

Figure3 is a perspective view of a component unitfor use in the method ofthe present invention andthe said unit is preferably pre-cast using concrete or other mouldable material.

Figure 4 is a side view ofthe component unit shown in Figure 3.

FigureS is a perspective view of an alternative component unit for use in the method of the present invention,the said unit being preferably made from timberorothersuitable material from which units can be formed in the manner shown in Figure 5.

Figure 6is a graph showing the relationship between the angle of slope of a wall, in accordance with the present invention, and the angle between adjacent units in anyone layer of units.

Figure 7is partofa diagramatic layout plan showing the relative positions of the lengths (L) ofthebasic units 1 ,the length (D) of the locking unit 3, and the angle (Z).

Figure 8 is a diagramaticcross section showing the relative positions ofthe locking unit3 of length (D) and the height of the unit (H).

Figure9shows diagramaticallythe plan layoutofa curved wall.

Figure 10shows diagramaticallythe plan layout of a wall containing a horizontal angle.

Figure 11 shows diagramaticallythe play layout of parts a wall containing one example of a reinforcing support.

Figure 12 shows diagramatically a sectional view of one example of a reinforcing support.

Figure 13 shows diagramatically a cross section incorporating one example of slope reinforcement.

Referring to the drawings, the perspective view of Figure 1 consists of a bottom horizontal layer ofthe basic units 1 connected atthejoints 2 to form interconnected V shapes. The second layer, of similar interconnected units, is stepped back so that the fronts ofthe V joints in the said second layerarevertically abovethe back of the Vjoints ofthefirst layer. The stepping back of each layer is continued succesively as each layer is added.

Unit3which is similarto the basic units 1, but may be different in length, is the connecting and locking unit between the front of a lower layer and the back ofthe next layer above. Insertion of the locking unit 3forms triangles in each ofthe diamond shapes formed by the V joints. Installation of this locking unit 3 is repeated to connect succesive vertical layers at all joints. As each layer is constructed suitable filling material is placed and compacted behind the unitsthusforming a series oftriangularshaped stepsto form the front of thewall.

With suitablefilling material these steps may be used as planting boxes for plants and vegetation,thus beautifying the slope. The slope angle 4 of the wall can be changed to suitthe angle of slope required by changing the height of units 1. This can be done by adding extra units on to any layer as illustrated in thetwo top layers in Figure 1 and shown as layer4and layer 5 in Figure 2. Alternativelythe units 1 are formed with a greaterheightto obtain the required change in slope.By increasing the number of units 1, or using units 1 with a greater height, in a layer at any level and continuing with the increased number of units 1 ,ortho increased height of the units 1 in each added layer, the slope angle S will be steepened from the level atwhich the heightofunits in a layer is first increased. Likewise with more than one unit in height, andthiswill reduce the slope angle ofthewall at any chosen level. Thus itis possibleto easilychangetheslope angle ofthewall atany level by increasing or reducing the numberofunitsforming the vertical height of each layer.

The component shown in Figure 3, for constructing the wall in one aspect of the present invention, is a type of unit which is preferably cast using concrete or other mouldable material It isformed to have a flat panel 1 between two cylindrical ends 2 which form the connecting joints with adjacent units and the unit is of a size and a weightwhich can be conveniently handled in constructing the wall. As shown in Figure4,the ends are madeto interlock horizontally, but pivot in the horizontal plane and are preferably formed with spherical shaped surfaces6 and 7 atthe upper and lower surfaces, the uppersurface being concave and the lower surface being convex so thatthe said speherical shaped surfaces match with similar surfaces on any units above and below the said unit.In each ene ofthesaid unit is a hole 8, which when aligned during the construction ofthe wall with units above or below the said unit, form a hollowtube at the centre of each pivotal joint.

The component shown in Figure S, for constructing the wall in one aspect of the present invention is a type ofunitpreferably made ofwood orothermaterial which can be formed in a like manneras shown in Figure4.

The said unit is a simple panel 1 with the ends formed as finger-like protruding parts 9, so that connection is madeto an adjacent unit by interlocking the finger-like ends. Holes 10 are bored through the protruding parts oftheendssothatwhen adjacent units are interlocked, the holes through the protruding parts are aligned through the said adjacent units and a suitable rod preferably of steel can be inserted to make a hinge-like connection between the adjacent units. If made of wood the units are suitably treated with chemicals in a known manner, to prevent rotting in the ground.

The graph of Figure 6showsthe relationship between the angle of inclination ofthewall (X), shown as4 and 5 in Figure 1 and Figure 2, and the horizontal angle (Z), between adjacent units in a layer, as shown in Figures 7 and 8. This relationship depends on the ratio ofthe length (L) and the height (H) of each unit. The said relationship is based on the mathematical formula: x=tan;1 H L*cos(Z/2) The information obtained from the graph in Figure 6 is applied to the design of a wall with a particularangle of inclination (X). As shown in Figure 6, provided the desired angle of inclination (X),the height of the units (H) and the length ofthe units (L) are known,the angle (Z) can be read from the graph and appliedtothe design ofthe horizontal plan layout ofthewall.

From the valueof(Z)therequired horizontal lengths between the V joints in any layer can be found from the mathematical formula: A= 2L*sin(Z/2) Also from the value of (Z) the length ofthe locking unit can be obtained as being the distance between the pivot of the front point of a Vjointand the pivot ofthe back ofthe V joint, by means of the mathematical formula: D = 2L*cos(Z/2) Thus all the required dimensions can be obtained for setting out the base layerand constructing all superimposed subsequent layers for a wall without horizontal angles or curvature in the horizontal plane.

Figure 9 shows one example of a curved wall in the manner of the present invention. The units in any particular layer are all ofthe same length, but in each successive layer above the base layerthe units are shorter by an amount calculated by known methods to form the required curvature. The top layer has the shortest units 11 in this configuration. The locking units3 are all ofthe same length as shown in Figure 9, but in some designsthe locking units may have a different lengths in each layer. It follows that forcurvature in the opposite sense, that is concave to the slope, the lengths of units in each of the succesive upper layers are longerthan the units in the layers below by an amount calculated by known methods.

Figure 10 shows one example of a wall containing a horizontal angle, forthe straight lengths at each side of the angle the component units are all asfora straightwall with units 1 being all the same in all layersand units 3 being all the same in all layers, butatthe angle in thewall, units 1112131415 are of different lengths calculated by known methods to suitthe horizontal angle between the two parts of the wall on each side of the angle.

Figure 11 shows one example of how slope reinforcing supports can be incorporated into the construction of the wall. The said supports are constructed with units identical to unit 1 to form a continuous vertical plane beneath the units forming the stepped frontface ofthe wall. The said reinforcing supports are constructed underneath a line of joints, and may be extended any distance under the wall to suit.

Figure 12 is a cross sectional view of Figure 11 and shows the position ofthe units forming the said reinforcing support 17 which is constructed with units identical to unit 1. Figures 11 and 12 illustrate oneform of a reinforcing support, butotherforms are possible with different configurations of units orwith extra units.

Figure 13 is a cross sectional viewofa wall such as shown in Figure 11 without a reinforcing support, to illustrate one method of constructing a wall with a lower duplicated wall builtto act as slope reinforcement within the fill material. The units ofthe slope reinforcement are identical to the units ofthewall constructed above as illustrated by units 1,2 and 3. More than two layers of slope reinforcement can be constructed inthe filling material to provide adequate strength to suit the design of the slope support.

Claims (7)

1. A diagonal form of crib-long wall, constructablefrom a multiplicity of interlocking identical pre-formed units connected pivotally into an integral structural entity with diamond shaped steps divided into triangles formed on thefrontface ofthewall in a manner providingfor a wide range of slope angles and variations in the slope angle at any chosen heights.

2. A diagonal form of crib-log wall as claimed in claim 1 with variation in the height of units 1 in selected layers to provide for a change in the angle of slope from any chosen heightofthewall.

3. A diagonal form of crib-log wall as claimed in Claim 1 or Claim 2with variation in the length ofthe unit 1 to provide for horizontal curvature in the wall.

4. A diagonal form of crib-log wall as claimed in Claim 1 or Claim 2 with variations in the lengths of a sufficient number of the interlocking units 1 to provide for horizontal angles between straight lengths ofwall.

5. A diagonal form of crib-log wall as claimed in Claim 1 or Claim 2 or Claim 3 or Claim 4 or claim Swith vertical reinforcing supports constructed with units identical to the multiplicity of units forming the crib-log wall.

6. A diagonal form of crib-log wall as claimed in claim 1 or Claim 2 or Claim 3 or Claim 4 or Claim 5with a duplication ofthe construction in the vertical direction to provide two or more layers ofthe constructed wall to reinforce the ground and create greater strength.

7. A diagonal form of crib-log wall substantially as described herein with reference to Figures 1-13 ofthe accompanying drawings numbered 1/6,2/6,3/6,4/6,5/6, and 6/6.