阅读说明：本技术 一种新旧防渗膜交接处焊接的施工工艺及其应用 (Construction process for welding joint of new and old impermeable membranes and application thereof ) 是由 赖见吾 熊艺浩 彭群兴 朱世浩 李晨 李栋 周章 王凯 于 2021-10-13 设计创作，主要内容包括：本发明涉及一种新旧防渗膜交接处焊接的施工工艺,防渗膜分为旧防渗膜和新防渗膜,在旧防渗膜的一侧拼接新防渗膜：将至少两层旧防渗膜和至少两层新防渗膜相互搭接,搭接方式为旧防渗膜和新防渗膜在层叠方向上间隔排布；最下层的旧防渗膜和最下层的新防渗膜之间采用双缝热熔焊接,其余位置相邻的旧防渗膜和新防渗膜之间采用单缝挤压焊接,每次焊接后均采用密封胶对焊缝进行二次密封。还涉及一种新旧防渗膜交接处焊接的施工工艺的应用,应用于垃圾填埋场的扩建。本发明具有很好的防渗效果,具有较高的连接强度,属于防渗工程技术领域。(The invention relates to a construction process for welding the joint of a new impermeable membrane and an old impermeable membrane, wherein the impermeable membrane is divided into the old impermeable membrane and the new impermeable membrane, and the new impermeable membrane is spliced on one side of the old impermeable membrane: overlapping at least two layers of old impermeable membranes and at least two layers of new impermeable membranes, wherein the overlapping mode is that the old impermeable membranes and the new impermeable membranes are arranged at intervals in the laminating direction; the old impermeable membrane at the lowest layer and the new impermeable membrane at the lowest layer are welded by adopting double-seam hot melting, the old impermeable membrane and the new impermeable membrane at the other positions are welded by adopting single-seam extrusion, and the seam is sealed secondarily by adopting a sealant after each welding. Also relates to the application of the construction process for welding the joint of the new and old impermeable membranes, which is applied to the extension of the refuse landfill. The invention has good anti-seepage effect and higher connection strength, and belongs to the technical field of anti-seepage engineering.)

1. The utility model provides a new and old prevention of seepage membrane handing-over department welded construction process, prevention of seepage membrane divide into old prevention of seepage membrane and new prevention of seepage membrane, splices new prevention of seepage membrane in one side of old prevention of seepage membrane, its characterized in that: overlapping at least two layers of old impermeable membranes and at least two layers of new impermeable membranes, wherein the overlapping mode is that the old impermeable membranes and the new impermeable membranes are arranged at intervals in the laminating direction; the old impermeable membrane at the lowest layer and the new impermeable membrane at the lowest layer are welded by adopting double-seam hot melting, the old impermeable membrane and the new impermeable membrane at the other positions are welded by adopting single-seam extrusion, and the seam is sealed secondarily by adopting a sealant after each welding.

2. The construction process for welding the joint of the new impermeable membrane and the old impermeable membrane according to claim 1, which is characterized in that: the lapping mode with the old impermeable membrane below is adopted.

3. The construction process for welding the joint of the new impermeable membrane and the old impermeable membrane according to claim 2, which is characterized in that: the double-seam hot melting welding part is characterized in that the welding seam is positioned between the end part of the old impermeable membrane at the lowest layer and the lower surface of the new impermeable membrane at the lowest layer, and is also positioned between the end part of the new impermeable membrane at the lowest layer and the upper surface of the old impermeable membrane at the lowest layer; and the single-seam extrusion welding part is positioned between the end part of the impermeable membrane and the upper surface of the next impermeable membrane and also covers the edge of the upper surface of the impermeable membrane.

4. The construction process for welding the joint of the new impermeable membrane and the old impermeable membrane according to claim 3, which is characterized in that: the width of the welding seam at the double-seam hot melting welding position is 2.5-3 cm; the width of the welding seam at the single seam extrusion welding position is 2-2.5cm, and the height is 2.0-2.5 cm.

5. The construction process for welding the joint of the new impermeable membrane and the old impermeable membrane according to claim 1, which is characterized in that: for double-seam hot-melt welding, the overlapping width of the old impermeable film and the new impermeable film is 100-130 cm; for single seam extrusion welding, the overlap width of the old and new barrier films is 130 to 150 cm.

6. The construction process for welding the joint of the new impermeable membrane and the old impermeable membrane according to claim 1, which is characterized in that: double-seam hot melt welding is carried out by adopting a self-creeping film hot melt welding machine, and single-seam extrusion welding is carried out by adopting a manual welding gun.

7. The construction process for welding the joint of the new impermeable membrane and the old impermeable membrane according to claim 1, which is characterized in that: and (3) bonding the lap joint part of the new impermeable membrane and the old impermeable membrane by using a hot air gun.

8. The construction process for welding the joint of the new impermeable membrane and the old impermeable membrane according to claim 1, which is characterized in that: detecting each layer of impermeable membrane after the connection is finished, and performing the operation of the next impermeable membrane after the connection meets the requirements; and after all the anti-seepage membranes are connected, the whole body needs to be detected.

9. Use of a construction process for welding the junction of a new and an old impermeable membrane according to any one of claims 1 to 8, characterized in that: the method is applied to the expansion of the refuse landfill.

10. The application of the construction process for welding the joint of the new impermeable membrane and the old impermeable membrane according to claim 9 is characterized in that: the method is characterized in that a plurality of layers of old anti-seepage films are paved at the bottom of a garbage stacking pool of an existing garbage landfill, an extended garbage stacking pool is additionally arranged at the joint of the existing garbage stacking pool, a plurality of layers of new anti-seepage films are paved at the bottom of the extended garbage stacking pool, and the old anti-seepage films and the new anti-seepage films are spliced by adopting a construction process of welding the joint of the new anti-seepage films and the old anti-seepage films.

Technical Field

The invention relates to the technical field of anti-seepage engineering, in particular to a construction process for welding the joint of a new anti-seepage membrane and an old anti-seepage membrane and application thereof.

Background

In recent years, welding between new and old impermeable membranes is a relatively novel membrane connection processing technology, and compared with a lapping and gluing method, the welding technology has a better seam impermeable effect, so that the welding technology between the new and old impermeable membranes becomes one of hot spots of new and old membrane connection research, and a plurality of engineering implementation cases exist. In actual construction, connection between new and old membranes is a key point for engineering quality control.

In the prior art, the geomembrane is generally welded by double seams, the welding is mostly carried out between single layers, and the multiple layers are only in a stacking and laying relationship.

From the prior documents and engineering cases, a construction technology for connecting new and old impermeable membranes by combining hot-melt welding and single-seam extrusion welding is not available for a long time.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention aims to: provides a construction process for welding the joint of the new and old impermeable membranes, which has firm connection and high sealing degree.

Another object of the invention is: provides the application of the construction process for welding the joint of the new and old impermeable membranes.

In order to achieve the purpose, the invention adopts the following technical scheme:

a construction process for welding the joint of a new anti-seepage film and an old anti-seepage film comprises the steps of dividing the anti-seepage films into the old anti-seepage film and the new anti-seepage film, splicing the new anti-seepage film on one side of the old anti-seepage film, and overlapping at least two layers of the old anti-seepage film and at least two layers of the new anti-seepage film in a manner that the old anti-seepage film and the new anti-seepage film are arranged at intervals in the laminating direction; the old impermeable membrane at the lowest layer and the new impermeable membrane at the lowest layer are welded by adopting double-seam hot melting, the old impermeable membrane and the new impermeable membrane at the other positions are welded by adopting single-seam extrusion, and the seam is sealed secondarily by adopting a sealant after each welding. After the arrangement is adopted, namely double-seam hot melting welding is adopted to connect the new and old films at the lowest layer, so that the integrity of the new and old films is improved, the quality of welding seams at the upper and lower lap joints is ensured, and the welding efficiency is improved; the new and old films above the lower layer are connected by adopting single-seam extrusion welding, so that the locality of a construction part is overcome, the quality of a welding seam at a lap joint is improved, and the connection between the layers is ensured; and the joint is sealed for the second time by adopting the sealant, so that the secondary protection effect is achieved.

As an optimal selection, a construction process for welding the joint of the new and old impermeable membranes adopts a lapping mode of the old impermeable membrane under. After the arrangement is adopted, the seepage-proofing effect of the new seepage-proofing film on the upper layer is ensured.

Preferably, the double-seam hot-melting welding position is that the welding seam is positioned between the end part of the old impermeable membrane at the lowest layer and the lower surface of the new impermeable membrane at the lowest layer and is also positioned between the end part of the new impermeable membrane at the lowest layer and the upper surface of the old impermeable membrane at the lowest layer; and the single-seam extrusion welding part is positioned between the end part of the impermeable membrane and the upper surface of the next impermeable membrane and also covers the edge of the upper surface of the impermeable membrane.

Preferably, the width of the welding seam at the double-seam hot melting welding position is 2.5-3 cm; the width of the welding seam at the single seam extrusion welding position is 2-2.5cm, and the height is 2.0-2.5 cm.

Preferably, for the double-seam hot-melt welding, the overlapping width of the old impermeable film and the new impermeable film is 100 to 130 cm; for single seam extrusion welding, the overlap width of the old and new barrier films is 130 to 150 cm.

Preferably, a self-creeping film hot-melt welding machine is adopted for carrying out double-seam hot-melt welding, and a manual welding gun is adopted for carrying out single-seam extrusion welding.

Preferably, the overlapping part of the new impermeable membrane and the old impermeable membrane is bonded by a hot air gun. After the arrangement is adopted, the connection is further strengthened on the basis of realizing the connection of the adjacent impermeable membranes by welding, and the firmness and the air tightness of the connection are improved.

Preferably, each layer of impermeable membrane is detected after the connection is finished, and the operation of the next impermeable membrane is performed after the requirement is met; and after all the anti-seepage membranes are connected, the whole body needs to be detected. By adopting the arrangement, the splicing quality of each layer and the whole is ensured.

An application of a construction process for welding the joint of a new impermeable membrane and an old impermeable membrane is applied to the extension of a refuse landfill.

Preferably, a plurality of old anti-seepage films are paved at the bottom of a garbage piling pool of an existing garbage landfill site, an expanded garbage piling pool is additionally arranged at the joint of the existing garbage piling pool, a plurality of new anti-seepage films are paved at the bottom of the expanded garbage piling pool, and the old anti-seepage films and the new anti-seepage films are spliced by adopting a construction process of welding the joint of the new anti-seepage films and the old anti-seepage films.

The principle of the invention is as follows: the joint of the new and old films at the lowest layer is welded by double-seam hot melting, so that the integrity and the sealing property of the lap joint of the new and old films are improved, and the construction period is saved; the single-side welding is adopted at the place where the two-side welding mode is difficult to adopt at the upper layer of the connection of the new and old films, so that the quality of the welding seam at the lap joint of the new and old films at the upper layer is improved, and the seepage prevention is ensured; the welding seam adopts sealant to carry out secondary sealing on the welding seam, thereby playing a secondary protection role and improving the impermeability of the joint of the new film and the old film.

The invention has the following advantages:

1. can solve the problem that the joint of the new and old impermeable membranes of the extension refuse landfill site is easy to leak, and compared with the traditional construction process, the average minimum density of the welding seam is 0.93-0.94g/m³Is increased to 0.949g/m³0.94g/m out of specification³So that the welding seam between the new film and the old film has better anti-seepage effect.

2. The strength of the joint of the new impermeable membrane and the old impermeable membrane can be ensured, the fracture resistance can be as low as 43.0N/mm and exceeds the standard requirement of 18.0N/mm, the requirement of tensile crack strength can be still met on the basis of the safety coefficient 2, and the percolate downflow caused by tensile crack generated in the later use process is avoided.

3. The method has the advantages that the requirements on the conditions of a construction site are reduced by combining double-seam hot melting welding and single-seam extrusion welding, so that the welding construction quality of the joint of the new and old impermeable membranes in the refuse landfill extension project is met.

4. And the sealant is applied, so that the sealing degree of the welding seam is improved through secondary sealing of the welding seam, and the welding seam is protected.

5. The construction method is simple and easy to understand, and welders can learn the construction sequence and the combination mode to perform welding construction on the basis of being familiar with the two welding processes.

6. The single-seam extrusion welding, the double-seam hot melting welding and the sealant coating process are not crossed, and the multilayer impermeable films are welded in a set process combination sequence to improve the construction quality under the characteristic construction conditions, complete the construction task and improve the impermeability of the joint position of the new impermeable film and the old impermeable film (improve 0.019 g/m) on the basis of the traditional process³) Strength (improved to more than two times of standard) and smoothness (error reduced to +/-0.49%) to ensure that the weakest position of the whole anti-seepage system cannot generate quality defects along with time in the later construction process.

Drawings

Fig. 1 is a schematic view of the connection of the new and old impermeable films by double-seam hot-melt welding.

Fig. 2 is a schematic view of the connection of the new and old impermeable membranes by adopting single-seam extrusion welding.

Fig. 3 is a flow chart of the construction process.

Fig. 4 is a graph showing the connection effect at the junction of the new and old impermeable membranes.

Wherein, 1 is the welding seam of double seam hot melt welding, 2 is the leak hunting cavity of welding seam, 3 is the old prevention of seepage membrane of lower floor, 4 is the new prevention of seepage membrane of lower floor, 5 is single seam extrusion welded welding seam, 6 is the old prevention of seepage membrane of second floor, 7 is the new prevention of seepage membrane of second floor, 8 is the old prevention of seepage membrane of superiors, 9 is the new prevention of seepage membrane of superiors.

Detailed Description

The present invention will be described in further detail with reference to specific embodiments.

A construction process for welding the joint of a new anti-seepage film and an old anti-seepage film comprises the steps of dividing the anti-seepage films into the old anti-seepage film and the new anti-seepage film, splicing the new anti-seepage film on one side of the old anti-seepage film, and overlapping at least two layers of the old anti-seepage film and at least two layers of the new anti-seepage film in a manner that the old anti-seepage film and the new anti-seepage film are arranged at intervals in the laminating direction; the old impermeable membrane at the lowest layer and the new impermeable membrane at the lowest layer are welded by adopting double-seam hot melting, the old impermeable membrane and the new impermeable membrane at the other positions are welded by adopting single-seam extrusion, and the seam is sealed secondarily by adopting a sealant after each welding.

Fig. 4 shows the lapping mode with the old impermeable membrane at the bottom, wherein the old impermeable membrane is at the left side and the new impermeable membrane is at the right side. The double-seam hot melting welding part is characterized in that the welding seam is positioned between the end part of the old impermeable membrane at the lowest layer and the lower surface of the new impermeable membrane at the lowest layer, and is also positioned between the end part of the new impermeable membrane at the lowest layer and the upper surface of the old impermeable membrane at the lowest layer; and the single-seam extrusion welding part is positioned between the end part of the impermeable membrane and the upper surface of the next impermeable membrane and also covers the edge of the upper surface of the impermeable membrane.

As shown in fig. 1, double seam hot-melt welding is adopted between the new and old impermeable membranes at the lowest layer. The double-seam hot melting welding adopts a novel self-creeping film hot melting welding machine, the welding speed is set to be 2.5m/min, and a welder stably pulls a handle to assist welding at a position which is difficult to weld by self.

The lapping width of the double-seam hot-melt welding is controlled between 100mm and 130mm, so that the part with serious loss of the old film joint is avoided.

Before welding, the film surface of the overlap joint of the new film and the old film within the transverse 200mm range is cleaned, before formal welding, equipment parameters are set according to experience, and a 400 multiplied by 800mm film block is taken for trial welding.

And after the double-seam hot-melting welding construction is finished, performing inflation quality inspection and tension crack, stripping and tightness tests between the double seams.

And (5) coating sealant on the weld joints in time after the double-seam hot-melt welding of the new and old impermeable films on the lowest layer is finished. The sealant adopts the existing liquid macromolecular static sealing material, and the liquid sealant can be directly coated on the joint surface by gluing, or can be coated by a scraper or a brush. The glue solution is continuous and uniform during smearing and can not lack glue. The coating thickness depends on the processing precision, flatness, clearance size and other conditions of the joint surface, and is generally 1.5mm-2 mm.

As shown in fig. 2, the old impermeable film of the second layer is lapped on the new impermeable film of the lowest layer, and the lap joint is connected by single-seam extrusion welding.

The single-seam extrusion welding adopts a manual welding gun held by a welder for welding due to the limitation of a field, and the welding speed is kept stable as much as possible.

The lapping width of single-seam extrusion welding is controlled to be 130mm-150mm, the lapping width is properly increased relative to the lapping width of double-seam hot melting welding, and the height of an extrusion welding seam is preferably 2.5 cm.

The overlapped parts of the new and old membranes are bonded by a hot air gun, the temperature of hot air is controlled, the HDPE geomembrane cannot be scalded and cannot be easily torn.

After the welding of the joint of the new and old impermeable membranes of the layer is finished, the new impermeable membrane of the second layer is lapped on the old impermeable membrane of the second layer after meeting the requirement, the single-seam extrusion welding is repeatedly carried out according to the requirement, and the welding of the new and old impermeable membranes of the upper layer is sequentially carried out, wherein in the embodiment, the new and old impermeable membranes are all three layers, as shown in figure 3.

And (4) welding the new anti-seepage film lap joint and the old anti-seepage film on the uppermost layer all the time, and finally carrying out integrity inspection on the anti-seepage system.

The minimum density standard requirement of the impermeable membrane is more than or equal to 0.94g/m³The traditional welding combination can reach 0.93g/m under limited conditions³-0.94g/m³The process combination can reach 0.949g/m³The above.

The tearing strength standard requirement of the impermeable membrane is more than or equal to 18N/mm, the traditional welding combination can reach 15N/mm-30N/mm under limited conditions, and the process combination can reach more than 43N/mm by using the invention.

The standard requirement of the tensile elongation at break of the impermeable membrane is more than or equal to 100 percent, the traditional welding combination can reach 100 to 200 percent under limited conditions, and the process combination can reach more than 556 percent.

The standard requirement of the dimensional stability (flatness) of the impermeable membrane is less than or equal to +/-2%, the traditional welding combination can reach +/-2% - +/-3% under limited conditions, and the process combination can reach +/-0.49% by using the invention.

An application of a construction process for welding the joint of a new impermeable membrane and an old impermeable membrane is applied to the extension of a refuse landfill. The method is characterized in that a plurality of layers of old anti-seepage films are paved at the bottom of a garbage stacking pool of an existing garbage landfill, an extended garbage stacking pool is additionally arranged at the joint of the existing garbage stacking pool, a plurality of layers of new anti-seepage films are paved at the bottom of the extended garbage stacking pool, and the old anti-seepage films and the new anti-seepage films are spliced by adopting a construction process of welding the joint of the new anti-seepage films and the old anti-seepage films.

The invention solves the connection problem of the new and old impermeable membranes in the construction process of the impermeable project by combining the double-seam hot melting welding and the single-seam extrusion welding, has advanced construction process, and effectively avoids the quality problem of incompact welding seams at the connection part of the new and old impermeable membranes in the construction process due to the inapplicability of the construction method.

The number of layers of the barrier film is selected according to the actual needs, except for the manner mentioned in this example. These variations are all within the scope of the present invention.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.