GB1601964A

GB1601964A - Reinforced earth structures

Info

Publication number: GB1601964A
Application number: GB3914577A
Authority: GB
Original assignee: TRANSPORT SECRETARY OF STATE F
Current assignee: TRANSPORT SECRETARY OF STATE F
Priority date: 1978-05-23
Filing date: 1978-05-23
Publication date: 1981-11-04

Description

(54) IMPROVEMENTS IN OR RELATING TO REINFORCED EARTH STRUCTURES (71) I, SECRETARY OF STATE FOR TRANSPORT, LONDON, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to reinforced earth structures.

Such structures comprise natural earth in which laterally-extending stabilising elements are embedded, the stabilising elements usually being attached to facing units covering an exposed upright face of a structure.

Such structures may be cuttings or embankments produced in connection with road works in which the facing units constitute retaining walls. Reinforced earth construction is advantageous in that the soil can be contained by retaining walls of much less massive construction than would be the case otherwise especially with particulate soils such as sands and gravel where there is little or no cohesion between particles, frictional contact between stabilising elements and the soil acting to enhance the stability of the structure.

Earth reinforcement is also applicable to more cohesive soils such as clay, with or ithout an admixture of soils of a more E,ranular nature.

Clay soils have a tendency to become compacted unevenly which can give rise to variations in stress acting on retaining walls which could cause failure; this is due in part to the water holding nature of cohesive soils such as clay and the problem can be aggravated in wet locations or by inclement weather.

The invention is directed, as are copending divisional applications hereof Nos 20294/70 as Serial nos 1607965, 1 601 967 20296/78, to reinforced earth structures having some flexibility to accommodate uneven compacting of soil and also to enable a variable configuration to be achieved.

The invention is not confined to cohesive soils and can find application with particulate soils.

According to the invention, a facing for a reinforced earth structure comprises a plurality of panel members arranged alternately with posts substantially T-shaped in plan in which the panel members abut against the inner faces of the cross-arms of adjacent posts to provide a substantially continuous structure, at least some of the post being provided with attachment means for connection of stabilising elements.

The invention also provides a reinforced earth structure comprising a facing as set out above and stabilising elements connected to at least some of the posts.

By a feature of the invention provision is made for relative movement between a facing and stabilising elements.

An embodiment of the invention will now be described by way of example only with reference to Figures 1 and 2 of the drawings accompanying the Provisional Specification which are respectively a plan view and a partial elevation of a facing for use with a reinforced earth structure.

A facing comprises pre-cast concrete posts and panels assembled together alternately as shown in the drawings. The posts 1 are generally T-shaped in plan, each being formed by a cross-arm having a tail portion extending centrally from one side.

The posts are erected vertically on a suitable concrete or other footing and spaced apart with their tail portions directed towards the proposed earth fill. The panels in the form of slabs 2 are mounted between the posts and abut against the inner faces of the cross-arms of adjacent posts to form a continuous structure which will serve to contain earth, the posts acting to support the panels against the pressure of the earth.

Axially-extending holes in the tail portions of the posts serve to receive steel rods or pins 3 which protrude above the level of the posts.

Stabilising or reinforcing, elements usually comprising steel strips are attached to the rods by holes formed at one end of the strips the free ends of which extend substantially horizontally into the earth-fill which is consolidated around them as erection of the facing proceeds. Stabilising elements can conveniently be of other material such as glass reinforced plastics or webbing, providing that it has adequate tensile strength and has a surface which will maintain good frictional engagement with the earth fill.

Further courses may be built up as necessary, the protruding ends of the rods 3 entering axially-extending holes in the tail portions of the additional posts and serving to locate the latter with respect to those previously positioned. Stabilising elements will thereby be disposed between successive posts which provide anchorage for the elements. The holes last mentioned extend through the posts and are used also for the insertion of further rods 3 for the location of additional posts or the attachment of stabilising elements as previously described.

A reinforced earth structure built up as described is flexible in that the shoulders of the posts support the panels in such a way that differential vertical and horizontal movement between posts and panels can take place so as to accommodate different degrees of earth settlement along the line of the facing and permit changes of the line.

Improved drainage can be obtained especially with cohesive soils by interposing granular material such as gravel between the main earth fill and facings. Seepage can be controlled by the use of compressible packing between posts and panels and which will also facilitate differential movement.

A construction as described may be erected without the need for mechanical handling equipment. The use of fabrication enables the ready production of posts and panels of varying dimensions to suit different sizes of structure, types of soil and stabilising element spacing. Specially shaped corner posts can enable large angular changes in the line of a facing.

WHAT I CLAIM IS: 1. A facing for a reinforced earth structure comprising a plurality of panel members arranged alternately with posts substantially T-shaped in plan in which the panel members abut against the inner faces of the crossarms of adjacent posts to provide a substantially continuous structure, at least some of the posts being provided with attachment means for connection of stabilising elements.

2. A facing for a reinforced earth structure according to claim 1 including posts having axially-extending holes in their tail portions and pins disposed in the holes to protrude therefrom.

3. A facing for a reinforced earth structure comprising a plurality of posts substantially T-shaped in plan with panel members arranged intermediately between the posts and in contact with the inner faces of the cross-arms thereof in which axially-extending pins protrude from the tail portions of the posts.

4. A facing for a reinforced earth structure according to claim 2 or claim 3 including further posts arranged to engage the pins.

5. A facing for a reinforced earth structure according to claim 4 in which the pins enter into axially-extending holes in the further posts.

6. A reinforced earth structure comprising a facing as claimed in any of claims 1--5 and stabilising elements connected to at least some of the posts.

7. A reinforced earth structure comprising a facing as claimed in any of claims 25 and stabilising elements connected to the pins.

8. A reinforced earth structure comprising a plurality of posts substantially Tshaped in plan and panel members arranged intermediately between the posts, the posts having axially-extending pins protruding from the tail portions thereof, and stabilising elements connected to the pins.

9. A reinforced earth structure according to claim 8 including further posts arranged to engage the pins.

10. A reinforced earth structure according to any of claims 69 comprising earth fill extending around the stabilising elements and acting to maintain the panels in contact with the posts.

11. A facing for a reinforced earth structure substantially as herein described with reference to Figures 1 and 2 of the drawings accompanying the Provisional Specification.

12. A reinforced earth structure substantially as herein described with reference to Figures 1 and 2 of the drawings accompanying the Provisional Specification.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

3 which protrude above the level of the posts.

Stabilising or reinforcing, elements usually comprising steel strips are attached to the rods by holes formed at one end of the strips the free ends of which extend substantially horizontally into the earth-fill which is consolidated around them as erection of the facing proceeds. Stabilising elements can conveniently be of other material such as glass reinforced plastics or webbing, providing that it has adequate tensile strength and has a surface which will maintain good frictional engagement with the earth fill.

Further courses may be built up as necessary, the protruding ends of the rods 3 entering axially-extending holes in the tail portions of the additional posts and serving to locate the latter with respect to those previously positioned. Stabilising elements will thereby be disposed between successive posts which provide anchorage for the elements. The holes last mentioned extend through the posts and are used also for the insertion of further rods 3 for the location of additional posts or the attachment of stabilising elements as previously described.

A reinforced earth structure built up as described is flexible in that the shoulders of the posts support the panels in such a way that differential vertical and horizontal movement between posts and panels can take place so as to accommodate different degrees of earth settlement along the line of the facing and permit changes of the line.

Improved drainage can be obtained especially with cohesive soils by interposing granular material such as gravel between the main earth fill and facings. Seepage can be controlled by the use of compressible packing between posts and panels and which will also facilitate differential movement.

A construction as described may be erected without the need for mechanical handling equipment. The use of fabrication enables the ready production of posts and panels of varying dimensions to suit different sizes of structure, types of soil and stabilising element spacing. Specially shaped corner posts can enable large angular changes in the line of a facing.

WHAT I CLAIM IS: 1. A facing for a reinforced earth structure comprising a plurality of panel members arranged alternately with posts substantially T-shaped in plan in which the panel members abut against the inner faces of the crossarms of adjacent posts to provide a substantially continuous structure, at least some of the posts being provided with attachment means for connection of stabilising elements.
2. A facing for a reinforced earth structure according to claim 1 including posts having axially-extending holes in their tail portions and pins disposed in the holes to protrude therefrom.
3. A facing for a reinforced earth structure comprising a plurality of posts substantially T-shaped in plan with panel members arranged intermediately between the posts and in contact with the inner faces of the cross-arms thereof in which axially-extending pins protrude from the tail portions of the posts.
4. A facing for a reinforced earth structure according to claim 2 or claim 3 including further posts arranged to engage the pins.
5. A facing for a reinforced earth structure according to claim 4 in which the pins enter into axially-extending holes in the further posts.
6. A reinforced earth structure comprising a facing as claimed in any of claims 1--5 and stabilising elements connected to at least some of the posts.
7. A reinforced earth structure comprising a facing as claimed in any of claims 25 and stabilising elements connected to the pins.
8. A reinforced earth structure comprising a plurality of posts substantially Tshaped in plan and panel members arranged intermediately between the posts, the posts having axially-extending pins protruding from the tail portions thereof, and stabilising elements connected to the pins.
9. A reinforced earth structure according to claim 8 including further posts arranged to engage the pins.
10. A reinforced earth structure according to any of claims 69 comprising earth fill extending around the stabilising elements and acting to maintain the panels in contact with the posts.
11. A facing for a reinforced earth structure substantially as herein described with reference to Figures 1 and 2 of the drawings accompanying the Provisional Specification.
12. A reinforced earth structure substantially as herein described with reference to Figures 1 and 2 of the drawings accompanying the Provisional Specification.