CN107524159B - A hybrid reinforced retaining wall - Google Patents

Abstract

The invention discloses a hybrid reinforced retaining wall, comprising a common wall panel, a prestressed wall panel, a wall panel foundation, an unbonded prestressed tendon, a side pressure plate, a geogrid and a filler. The two types of wall panels are supported on the foundation of the wall panels, the prestressed wall panels are connected with the unbonded prestressed ribs, the ordinary wall panels are connected with the geogrid, and a vertical unbonded prestressed rib is arranged between two layers. Layer or multi-layer geogrid, one end of the unbonded prestressed tendon is connected with the side pressure plate, and the other end is tensioned and anchored on the prestressed wall panel; the present invention combines the traditional reinforced soil technology with the unbonded prestressed reinforcement The combination of technologies not only uses the traditional reinforced soil technology to passively constrain the filler by relying on the friction of the reinforced soil, but also plays the role of the unbonded prestressed reinforced soil technology to enhance the active constraint of the filler. It not only improves the economy of the unbonded prestressed reinforced soil technology, but also reduces the construction difficulty of the unbonded prestressed reinforced soil technology.

Description

A hybrid reinforced retaining wall

technical field

The patent of the present invention relates to the field of retaining walls, in particular to a hybrid reinforced retaining wall.

Background technique

The unbonded prestressed reinforcement technology is an efficient geotechnical reinforcement technology. The technology actively extrudes the filler through the tension of the prestressed tendons in the main stress part to form a compression zone. The filler in this compression zone is in a triaxial position. The compressive stress state increases the shear strength of the filler, improves the internal stability of the retaining wall, and reduces the soil deformation. Compared with ordinary reinforced soil technology, the use of this geotechnical reinforcement technology can further reduce the horizontal deformation and vertical deformation of the retaining wall, and can control and adjust the prestress level according to actual needs, and can be supplemented during the construction process. Tensioning reduces the loss of prestress, especially for projects with high requirements on deformation control and appearance, and has good applicability.

In traditional reinforced soil technology, only when the filler is deformed, the reinforced material can passively exert a restraint effect. Its restraint effect on the filler is not as strong as that of the unbonded prestressed tendons, and the lateral deformation is often large, but it has The advantages of low cost and simple construction, if the advantages of the two are combined, it will have both economical and applicable advantages.

The reinforcement materials used in the non-bonded prestressed reinforcement technology before the present invention have been optimized many times by our research group in recent years, see Chinese patents CN102877468B, CN102864711B and CN104005396B. These optimizations are mainly to change the internal reinforcement material of the original main stress part from polygonal high elastic modulus reinforcement materials (such as galvanized steel strips and carbon fiber steel plates) to circular steel strands; change the original main stress part The external reinforcement material of the secondary force-bearing part is changed from the same material as the outer layer of the main force-bearing part to the geogrid. The inner reinforced material of the main force-bearing part can slide freely in the outer reinforced material, and the outer reinforced material of the main force-bearing part and the reinforced material of the secondary force-bearing part are connected to each other, and the interlocking forms a kind of active restraint and Composite stiffeners for passive restraint capabilities.

This improved reinforcement method still has the following problems: 1. The internal reinforcement material (ie prestressed reinforcement) subjected to prestress has a strong active constraint on the soil, and the soil at the location of the reinforcement material layer has a strong active constraint force. The deformation is generally small, and the reinforced material of the secondary stress part (ie the geogrid) is in direct contact with the soil. There is a contradiction in the large deformation of the soil. Therefore, placing two kinds of reinforced materials with different mechanisms of action, the reinforced material under prestressing and the reinforced material in the secondary stress part, on the same horizontal layer will greatly limit the high-strength performance of geogrids. , this kind of reinforcement method requires a large number of layers of prestressed reinforcement materials and a large number of anchors, and the construction cost is large; 2. The external reinforcement materials (polypropylene or polyvinyl chloride round pipes) of the main stress-bearing parts are different from The connection of the geogrid is complicated, and the construction quality is difficult to guarantee.

SUMMARY OF THE INVENTION

In view of the above-mentioned deficiencies of the prior art, the purpose of the present invention is to solve the problems that the prestressed reinforced material limits the high-strength performance of the geogrid, the connection is complicated, and the cost is high, and further provides a hybrid reinforced retaining wall.

The purpose of this invention is to realize through the following technical solutions:

A hybrid reinforced retaining wall is characterized in that: it includes ordinary wall panels, prestressed wall panels, wall panel foundations, unbonded prestressed tendons, side pressure plates, geogrids, and fillers, and the wall panels are supported on On the basis of the wall panel, the prestressed wall panel is connected with the unbonded prestressed reinforcement, the ordinary wall panel is connected with the geogrid, and one or more layers of geogrid is arranged between the two vertical layers of the unbonded prestressed reinforcement. One end of the unbonded prestressed tendon is connected with the side pressing plate, and the other end is tensioned and anchored on the prestressed wall panel. The geogrid ensures the stability of the ordinary wall panel during the construction process. After the retaining wall structure is formed, it ensures the local stability of the retaining wall between the two layers of prestressed reinforced materials, which provides passive restraint force; the prestressed reinforcement The material uses the prestressed wall panel and the side pressure plate to actively squeeze the filler between the two panels, and the confining pressure of the filler is enhanced to increase its strength and provide an active restraint force. The two reinforced materials and the filler together form a reinforced body to maintain soil retention The stability of the wall, reduce the deformation of the wall.

The non-bonded prestressed tendons are made of high-strength and low-relaxation steel strands, and the surface is coated with special non-bonded prestressed anti-corrosion grease and sleeved in a PVC pipe. The common wall panel and the prestressed wall panel are prefabricated from reinforced concrete materials. The fillers are non-sticky fillers such as sandy soil or gravel soil, and expansive soil, organic soil and silt are not allowed. When the construction site lacks non-adhesive fillers or the cost is high, non-adhesive fillers can be used only within a certain thickness range on both sides of the geogrid reinforced layer, and general fillings on site are used in other ranges.

Further, the inner surface of the wall panel is provided with horizontal and vertical ribs to increase the flexural rigidity without excessively increasing the thickness of the panel, and an anchor hole is left at the intersection of the horizontal and vertical ribs; the outer side of the anchor hole is inward Recessed so as to be flush with the outer surface of the wall panel after the anchor is sealed; the back of the ordinary wall panel is pre-buried with connecting steel bars extending out of the panel surface; the ordinary wall panel and the prestressed wall panel are provided with interconnecting mouth.

Further, the vertical spacing of the adjacent unbonded prestressed bars is not less than 0.6m and not more than 2.5m; when laying multi-layer geogrids between the unbonded prestressed bars, the vertical The spacing is not less than 0.3m and not more than 0.7m.

Further, the length of the geogrid is not less than 0.2 times and not more than 0.4 times the height of the retaining wall.

Further, the length of the unbonded prestressed tendons is greater than the length of the geogrid.

Further, the compaction degree of the filler is not less than 90%.

Correspondingly, the present invention also proposes a construction method for a hybrid reinforced retaining wall. First, level the site, excavate blind drainage ditch and foundation pit for retaining wall panel foundation, and pour the wall panel foundation; After the foundation, fill the filler and compact it until the location where the reinforcement material is laid. If the geogrid is laid at this location, lay the reinforcement material on the compacted filler, install the ordinary wall panel, and connect the geogrid with the ordinary wall. The panel is connected and fixed, and the common wall panel is initially fixed through the groove between the geogrid and the wall panel; if the unbonded prestressed tendons are laid in this position, it is necessary to install the buried side pressure plate first, lay the unbonded prestressed tendons and It is initially connected with the side pressure plate and the prestressed wall panel, and the prestressed wall panel is initially fixed through the groove between the unbonded prestressed tendon and the wall panel, and then continues to be filled and compacted until the next reinforced material laying position. ;Continue from bottom to top until the design height of the retaining wall; Finally, apply prestress to the unbonded prestressed tendons to the design value according to the design requirements; Tension and seal anchors on prestressed wall panels.

Compared with the prior art, the beneficial effects of the present invention are:

This kind of hybrid reinforced retaining wall has the dual advantages of ordinary reinforced soil retaining wall and unbonded prestressed reinforced retaining wall, which is embodied in:

1. The geogrid and the unbonded prestressed tendons are arranged at different layers to avoid the strong restraint ability of the unbonded prestressed tendons, which limits the exertion of the high-strength characteristics of the geogrid, making the stress more clear and reasonable.

2. The cost of geogrid is relatively low. This mixed reinforcement method reduces the amount of prestressed reinforcement and anchorage used, and reduces the cost and technical difficulty of construction.

3. It avoids the complicated construction process in which the geogrid and the unbonded prestressed tendons are connected to each other to ensure the construction quality.

4. The retaining wall adopts directly prefabricated and assembled wall panels and side pressure plates, and the wall panels are designed with tongue and groove connection, which is convenient for construction and beautiful in appearance, especially suitable for municipal engineering with high requirements on deformation and appearance.

5. When setting geogrids and unbonded prestressed tendons at different levels, the requirements for fillers can be reduced: that is, only the non-stick fillers are filled within a certain thickness range above and below the geogrids, while other layers are used on-site. Fill the soil to further reduce the cost.

Description of drawings

Fig. 1 is the cross-sectional view of the hybrid reinforced retaining wall of the present invention

2 is a three-dimensional schematic diagram of the internal reinforcement structure of the hybrid reinforced retaining wall of the present invention

3 and 4 are three-dimensional schematic diagrams of the inner and outer surfaces of the prestressed wall panel of the present invention

5 and 6 are three-dimensional schematic diagrams of the inner and outer surfaces of the common wall panel of the present invention

7 and 8 are three-dimensional schematic diagrams of groove-and-mouth connection of wall panels of the present invention

Figure 9 is a schematic diagram of an alternative filler usage of the present invention

In the attached drawings: 1─Ordinary wall panel, 2─Prestressed wall panel, 3─Wall panel foundation, 4─Unbonded prestressed reinforcement, 5─Side pressure plate, 6─Geogrid, 7─Filling, 8─Anchor Tool, 9─Connecting steel bars, 10─Field fill, 11─Blind drainage ditch

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Referring to the accompanying drawings 1 to 2, the hybrid reinforced soil retaining wall of the present invention is shown, including a common wall panel 1, a prestressed wall panel 2, a wall panel foundation 3, an unbonded prestressed tendon 4, and a side pressure plate 5, Geogrid 6, Filling 7. One end of the unbonded prestressed tendon 4 is connected to the side pressure plate 5 embedded in the filler 7 , and the other end is anchored on the prestressed wall panel 2 after being stretched by the anchor 8 . Referring to Fig. 3-Fig. 4, the back of the prestressed wall panel 2 has horizontal and vertical ribs, and an inwardly recessed anchor hole is left at the intersection of the horizontal and vertical ribs; with reference to Fig. 5-Fig. 6 As shown in the figure, the back of the common wall panel 1 is not provided with ribs, and there are pre-embedded connecting steel bars 9 extending out of the panel surface. Referring to Figures 7-8, two kinds of wall panels are provided with grooves and mouths for mutual connection around them. Referring to Figure 9, when the construction site lacks non-sticky filler 7 or in order to reduce costs, non-sticky filler 7 can be used only within a certain thickness range on both sides of the geogrid reinforced layer, and field fill is used in other ranges. 10.

The specific steps of the construction method of the above-mentioned hybrid reinforced retaining wall are as follows:

1) Level the site, excavate the drainage blind ditch 11 and the foundation pit of the wall panel foundation, fill the blind ditch with pebbles and other easy-draining fillers, and pour the wall panel foundation 3 in the retaining wall foundation pit; The tendon material is transported to the site to be ready in place.

2) After the wall panel foundation 3, fill the filler 7 layer by layer and compact it until the reinforced material is laid. The first layer can choose the ordinary wall panel 1 and the geogrid 6 according to the actual situation, or you can choose the prestressed wall panel. 2 with unbonded prestressed tendons 4. The wall panels of the first layer are directly supported on the wall panel foundation 3, and the wall panels are connected with the surrounding wall panels through tongue and groove. When the height of the filler 7 reaches the reinforced material laying position, if the geogrid 6 is laid at this position, then the geogrid 6 is laid on the compacted filler 7, the ordinary wall panel 1 is installed, and the geogrid 6 and the The ordinary wall panel 1 is connected and fixed by the pre-embedded connecting steel bars 9; if the unbonded prestressed rib 4 is laid in this position, it is necessary to reversely excavate the groove of the side pressure plate and the groove of the unbonded prestressed rib, and place the side pressure plate 5 And the unbonded prestressed tendons 4 are laid in the corresponding grooves, then the prestressed wall panels 2 are installed, the fast-hardening concrete is poured into the grooves of the side pressure plate and the anchors 8 on the side pressure plate are wrapped; Fill the top with filler and compact it until the position of the next reinforcement layer; the field fill 10 behind the reinforcement area is simultaneously filled and compacted with the filler 7;

3) Repeat the installation process of step 2) until the entire retaining wall is completed;

4) Prestress the unbonded prestressed tendons 4 to the design value according to the design requirements. The design value has no ready-made specification for reference, and can be determined by comprehensive means such as finite element analysis and design experience of ordinary anchor plate retaining walls;

5) If the prestress loss is too large or unstable when the prestress is applied in step 4), the anchors (8) on the prestressed wall panel can be sealed and anchored without fine stone concrete, but the fillers can settle for a period of time. After that, the supplementary tension is performed again, and then the anchor holes in the depressions on the outer side of the prestressed wall panel 2 are sealed and anchored so that the outer surface of the prestressed wall panel 2 is flush, and the construction is completed.

The blind drainage ditch 11 in the above step 1) is arranged at the connection position of the base retaining wall filler 7 and the field fill 10. The blind ditch is provided with horizontal drainage channels every 10m, and the water in the blind ditch is led out of the retaining wall.

During the installation of the wall panel in the above step 2), for the low retaining wall (3-5m), no temporary support is required, and the reinforced material behind the wall panel and the connection of the surrounding grooves can be used directly to maintain the wall panel. Stable, when the retaining wall is high (greater than 5m), temporary support is required, and it can be removed after the prestress is applied.

The above descriptions are only specific embodiments of the present invention, and are not intended to limit the scope of the present invention. Equivalent changes, modifications and combinations proposed by any person skilled in the art without departing from the concept and principles of the present invention shall fall within the protection scope of the present invention.

Claims (6)

1. A hybrid reinforced retaining wall, comprising a common wall panel (1), a prestressed wall panel (2), a wall panel foundation (3), an unbonded prestressed tendon (4), and a side pressure plate (5) , geogrid (6), filler (7), characterized in that: the wall panel is supported on the wall panel foundation (3), and the two ends of the unbonded prestressed tendon (4) are respectively connected to the prestressed wall panel (2). ), the side pressure plate (5) is connected, the geogrid (6) is connected with the common wall panel (1), and one or more layers of geogrids ( 6); geogrids (6) and unbonded prestressed tendons (4) are arranged at different layers; the side pressure plates (5) are embedded in the filler (7); the length of the unbonded prestressed tendons (4) is greater than Length of geogrid (6). 2. The hybrid reinforced retaining wall according to claim 1, characterized in that, the back of the prestressed wall panel (2) has horizontal and vertical ribs, and anchors are left at the intersection of the horizontal and vertical ribs The outer side of the anchor hole is recessed inward, so that it can be flush with the outer side of the wall panel after the anchor is sealed; the back of the common wall panel (1) is pre-embedded with connecting steel bars (9) extending out of the panel surface; the common wall panel (1) 1) and the prestressed wall panel (2) are provided with grooves for interconnection all around. 3. The hybrid reinforced retaining wall according to claim 1, characterized in that the vertical spacing of adjacent unbonded prestressed tendons (4) is not less than 0.6m and not more than 2.5m; When laying multi-layer geogrids between the prestressed tendons (4), the vertical spacing of the geogrids shall not be less than 0.3m and not greater than 0.7m. 4 . The hybrid reinforced retaining wall according to claim 1 , wherein the length of the geogrid ( 6 ) is not less than 0.2 times and not more than 0.4 times the height of the retaining wall. 5 . 5 . The hybrid reinforced retaining wall according to claim 1 , wherein the compaction degree of the filler ( 7 ) is not less than 90%. 6 . 6. the construction method of hybrid reinforced retaining wall according to claim 1, is characterized in that, comprises the steps: 1) Leveling the site, excavating blind drainage ditch (11) and foundation pit for retaining wall panel foundation, and pouring wall panel foundation (3); 2) Fill the filler (7) and compact it until the location where the reinforcement material is laid. If a geogrid (6) is laid at this location, spread the reinforcement material on the compacted filler (7), and install the ordinary wall panel ( 1), and connect the geogrid (6) to the ordinary wall panel (1) through the connecting steel bar (9); if the unbonded prestressed bar (4) is laid in this position, the embedded side pressure plate (5) needs to be installed first. , and then lay the unbonded prestressed tendons (4) and connect them with the side pressure plate (5) and the prestressed wall panel (2), and continue to fill and compact until the next reinforced material laying position; 3) Repeat step 2) from bottom to top until the design height of the entire retaining wall; 4) Prestress the unbonded prestressed tendons (4) to the design value according to the design requirements; 5) According to the degree of loss of prestress in step 4), it is determined whether subsequent supplementary tension is required. After the prestress is applied, the anchorage (8) on the prestressed wall panel (2) is sealed and anchored, and the construction is completed.