EP0216422B1

EP0216422B1 - Soundproof wall

Info

Publication number: EP0216422B1
Application number: EP86201553A
Authority: EP
Inventors: Hans Riede
Original assignee: Holding Riede BV
Current assignee: HOLDING RIEDE B.V.
Priority date: 1985-09-10
Filing date: 1986-09-10
Publication date: 1990-08-08
Anticipated expiration: 2006-09-10
Also published as: DK161981C; EP0216422A1; DK161981B; DK431386A; ATE55435T1; DE3673299D1; DE216422T1; DK431386D0; NL8502467A

Abstract

A live willow-faced, earth-core noise barrier is built by setting two spaced paralled rows of spaced willow stakes (1) into the ground (2), horizontally interweaving in each row osiers (4) with the stakes (1), and filling with soil the space between those two woven walls which have been previously interconnected by tension wires (5) linking the top part of stakes (1) thereof. The barrier is built to the required height in successive stages, the further stakes being set into the soil fill of the previous section.

Description

The invention relates to a process for erecting a soundproof wall or a wall used for other purposes by planting in the soil rows of branches, preferably of willow, which may or may not already have roots, and having them grow in such a way that they are at least partly able to grow between and against each other. Such a soundproof wall is known from the Dutch Patent Application 8 202 277, wherein the woodpoles are closely placed in the soil and means, such as amongst others a corrugated plates, are connected with the poles in order to obtain a substantially closed wall immediately after placing the woodpoles. To simplify the dense placing of the woodpoles the poles can a.o. be connected by transversally to the longitudinal direction of the poles extending and in spaced relationship placed threads, ropes and so on, which intertwine around the consecutive poles so that a kind of weaving is obtained. This construction is based on wall formation as a consequence of the increasing thickness of the densily placed willowwood poles in the course of time. However owing to the natural properties of the planted willowwood poles in the course of time also holes will be formed. There is further the objection that one uses corrugated plates and other materials, while also the erection of relatively high walls causes problems because straight willowwood poles with a length of more than two metres are not easily obtainable and moreover difficult to manipulate.
The process of the invention is intended to alleviate these objections and to offer the possibility of erecting the soundproof wall in steps to a desirable height.
Thus the process indicated in the preamble is according to the invention characterised in that two rows of branches are planted a substantial distance a part, which branches are in the form of poles which preferably are pointed at the bottom, that the poles of each row are inserted in the soil a substantial distance from each other, that between the sub- tantially vertical poles of each row osiers are woven in the general longitudinal direction of the row, that the rows are connected with each other by means of tension wires located adjacent the tops of the poles and extending between the rows, and that a soil blend is filled in between the rows. This process can be repeated as indicated in claims 2 and 3.
Although this process is in principle not limited to a particular dimension of the poles, one will in practice start from easily available materials, by means of which a soundproof wall with a length of at least one meter can be erected.
Thus one preferably starts from pointed willowwood poles which are put in the soil at a relative distance of 30-70 cm and preferably about 50 cm, a second row being applied at a substantial distance from the first row.
Preferably one uses poles with such a length that they will rise about 1 metre above the soil. Poles with dimensions of 1% to 2 metres which are placed a sufficient distance in the soil are very suitable to form a dense composite. A very suitable dimension is about 175 cm. Between the willowwood poles vertically put in the soil osiers are woven in longitudinal direction to build up the wall. For this purpose osiers of 2 to 3 years old are very suitable because of their resilience and elasticity. The wall obtained is now finished by placing a good moisture containing soil blend between the two erected rows of woven poles. To control sagging of the edges as a consequence of the lateral soil pressure, reinforcement materials, like in particular tension wires, are inserted between both rows of poles. Especially suitable materials are inert plastic wires like nylon wires, which wires are interwoven e.g. 10 cm below the top of the poles, as well as prefabricated tightening wires of for example plated iron. It is to be understood that also other types of inert strong wires materials are possible.
The willowwood poles put in the soil will form roots during the growing season and become thicker, so that the strength above as well as below the soil will increase. The horizontally woven willow twigs (osiers) will by contact with the soil applied and by the locally preliminary elimination of the rind at the soil side also form roots, so that a dense composite will arise. Such a construction offers the advantage that after finishing the weaving of the osiers by the connection with nylon wire and supplying soil, the soundproof wall can again be erected in the same approximate height by again inserting willowwood piles at the inner side of the weaving in the soil applied and to repeat the already mentioned steps. In practice a soundproof wall with a height of about 3 meters can in three stages be built up. For the construction of this soundproof wall one uses particularly willow materials because of their fast way of growing. However depending on the constitution of the soil, the plants growing on the spot, and other circumstances one can also use other types of branch (pole) material beside each other or blended together.
As to the filling of the soundproof wall one will preferably make use of types of soil which have sufficient moisture retaining power to promote the growth of the osiers. In principle it is possible to use even blends that satisfies these conditions. Suitable soil blends are sandy clay ground, peat ground or clay ground, which may or may not be mixed with other materials. On very soft types of soil with less bearing power one may use lighter soil blends, for instance by blending the soil referred to with expanded clay pellets, for example in amounts of 1-3 per cent or more.
The provision of water to the soil between the rows in dry periods takes place by means of a dripping system which is in the upper part of the wall. To prevent unnecessary evaporation and to replenish the possibly set soil the split up prunings of the emerged willows may as a top layer be applied on the soil in question. The mowing of the willows after these are emerged, should maximally take place once a year and minimally once per three years.
Owing to shortage of space not all horizontally woven willows will take roots. A part of the interwoven fence has real life chances. This part will gradually replace the osiers' that have died so that a dense combination will be retained.. The osiers, which have made no roots, will retain their strength about 4-5 years. The construction of the soundproof wall in stages with the help of relatively short willowwood poles with a diameter of 4-5 cm has the advantage that the pole length is in itself not binding and that there is a large supply of well manipulable willowwood poles below 2 metres. For poles longer than 2 metres the weaving thereof will also become more difficult. The shorter willowwood poles may be younger and so will easier form roots. Because the vertical poles have a large relative distance, about 50 cm, which distance is necessary to avoid a too large root competition in the soil, one may if no formation of roots takes place simply put a thinner pole beside the dead pole in the mat. The thicker but dead pole will also in the first years provide further firmness. In case of greater lengths of the poles one would have to use tension means which constrict the pole halfway so that the chance of mortality becomes greater. In the present process the necessary stretching wires only constrict the willowwood poles at the top. It is to be understood that if the soundproof wall has by the favourable development obtained a greater stability, one may if need be construct a fourth stage. It is evident that it is to be preferred to use the willowwood poles and osings directly after cutting them. This cutting should take place in the period between November and April.
The invention will now further be illustrated by means of the drawing, wherein:

Figure 1 is a cross-section of the soundproof wall wherein three stages are indicated from which the wall is built up;
Figure 2 shows a panoramic view of a poles construction according to the invention; and
Figure 3 is a variation of Figure 2.

In Figure 1 with 1 the willowwood poles are indicated which are used in the three stages. By way of example, the willowwood pole may in the first stage have a length of 175 cm, in the second stage a length of 150 cm and in the third stage a length of 150 cm, with a diameter of in general 4-5 cm. The tips 3 of the poles are put in the soil, wherein the soil is indicated by 2. The woven osiers are indicated with 4, and the tension wires with 5. The moisture containing soil in the various stages is indicated by different types of black gradation. At the top of the wall the shaded part 6 shows the layer of scrapped wood material, by which the setting of the soil may in the course of time be controlled.
In Figure 2, wherein the same reference numerals have the same meaning, a part of the weaving with willow osiers of 2-3 years is shown, and further the tension wires 5, which are fixed from below upwards, each time for supplementing soil to a stage, are clearly indicated.
In Figure 3 a same construction is shown, however with the difference that prefabricated tension wires of plated iron 5' are used, which are attached between two opposite poles. As follows from the Figures the soundproof wall also has an inclination, which is favourable to prevent reflection of sounds, for instance over a highway. In the sound- wall as shown at the upper part a sharp delimitation is present, by which dispersion of sound is prevented. Thus the invention provides a soundproof wall, separation means or windbreaker, which is favourable for the environment and more or less forms part thereof.
The invention offers the advantages that the willow material provides various functions, i.e. a constructive function providing strength, a sound proofing function i.e. absorbing sound waves, and an esthetic function as forming part of the environment. It further has the inherent advantage of emerging on own force, necessitating of course the use of living willow branches.

Claims

1. Process for erecting a soundproof wall used for other purposes by planting in the soil (2) rows of branches a substantial distance apart, preferably of willow, which may or may not already have roots, characterized in that two rows of branches are planted (1) which branches are in the form of poles which preferably are pointed at the bottom, that the poles of each row are inserted in the soil a substantial distance from each other, that between the substantially vertical poles of each row osiers (4) are woven in the general longitudinal direction of the row, that the rows are connected with each other by means of tension wires (5) located adjacent the tops of the poles and extending between the rows, and that a soil blend is filled in between the rows.

2. Process according to claim 1, wherein the soundproof wall is heightened by repeating the process according to claim 1.

3. Process according to claim 2, characterized in that the soundproof wall is built up in three stages.

4. Process according to claims 1-3, characterized in that the poles (1) are put in the soil (2) at such a relative distance that there is enough space to control the large root competition in the soil (2).

5. Process according to claims 1-4, characterized in that willowwood poles (1) are used in lenghts not greater than 2 metres.