CN107059523A - A kind of construction method that road is built on reclaimed ground and the subgrade strengthening structure of construction method formation - Google Patents

Abstract

The invention discloses a construction method for constructing a road on a dredged fill soil foundation and a roadbed reinforcement structure formed by the construction method. By combining the filled silt film bag with a three-dimensional composite drainage network and water collection well drainage, the upper layer of the dredged fill soil The hard shell structure is formed, and the subgrade structure is initially formed; then, the deep plastic drainage board is laid, the sand layer is laid, and the pressure is applied to the membrane bag layer and the blown fill soil foundation by setting an overload preload to further promote the drainage in the membrane bag. The water discharge of the filled silt soil and the water discharge of the dredged soil foundation realize simultaneous reinforcement of the mud bag and deep foundation soil; when the deformation conditions of the roadbed meet the engineering requirements, the load is removed, and the upper roadbed and road surface are built.

Description

A construction method for constructing a road on a dredger filled soil foundation and the formation of the construction method roadbed reinforcement structure

technical field

The invention belongs to the technical field of design and construction of road structures on weak foundations of civil engineering, and in particular relates to a construction method for building roads on dredging and filling soil foundations.

Background technique

In recent years, with the rapid development of my country's port construction, the phenomenon of insufficient land resources has become increasingly prominent, and land reclamation has become an important means for most port cities to solve industrial land.

In order to meet the requirements of land reclamation, tide and wave prevention, and transportation, it is necessary to build sea blocks, fences and roads on the dredger fill. The traditional method requires a large amount of external engineering materials such as silt, fine sand, mountain soil, and block stones. The mining, transportation and construction of these ground materials not only cause environmental damage to the location where the materials are collected, but also cause pollution and damage to the ocean. The amount of work is large and the cost is high. Therefore, in order to reduce costs and protect the environment, it is necessary to develop a new method for road construction.

Contents of the invention

The purpose of the invention is to overcome the deficiencies of the prior art and provide a construction method for constructing a road on a dredged fill foundation.

The present invention is achieved through the following technical solutions:

A construction method for constructing a road on a dredger filled soil foundation, comprising the following steps:

Step 1: Drain the accumulated water on the surface, lay brambles or bamboo fences or netted bamboo rafts on the original mud surface (0) as the foundation work cushion (1), place the bottom box of the water collection well (2) according to the well position of the water collection well, and Vertically install the sump connecting pipe (3);

Step 2: laying a layer of geotechnical non-woven fabric (4) on the working cushion (1), and making the water collection well connecting pipe (3) pass through the reserved sleeve (5) of the geotechnical non-woven fabric;

Step 3: Lay a layer of three-dimensional composite drainage network (6) on the geotextile non-woven fabric (4), and make the water collection well connecting pipe (3) pass through the reserved sleeve (7) of the three-dimensional composite drainage network (6);

Step 4: Lay a layer of geomembrane bag (8) on the three-dimensional composite drainage network (6), then fill the first layer of muddy soil (9) into the first layer of geomembrane bag (8); After the first layer of silt (9) is consolidated to form a certain strength, then repeat steps 3 and 4, continue to lay a new layer of three-dimensional composite drainage network 6 and geomembrane bag laying, and fill with muddy soil until the construction reaches the predetermined level. Set the top elevation;

Step 5: Lay a layer of geotechnical non-woven protective layer (10) on the topmost geomembrane bag, ensure that the non-woven protective layer (10) covers the entire base surface, and embed its edge into the soil;

Step 6: Lay a sand layer (11) on the non-woven protective layer (10), and then set up a vertical plastic drainage board (12), the bottom of the plastic drainage board goes deep into the dredging and filling soil base, and the plastic drainage board (12) The board head is buried in the sand layer (11);

Step 7: laying the mountain soil structure layer (13) on the sand layer (11);

Step 8: Lay the heap load (14) layer by layer on the mountain soil structure layer (13), and drain the water collection well; remove the heap load (14) when the deformation conditions meet the engineering requirements, and stop the drainage of the water collection well ;

Step 9: constructing a masonry shoulder (15) on the mountain soil structure layer (13), and constructing a pavement base (16) and a pavement surface (17), and the road structure is completed.

In the above technical scheme, the connection pipe of the water collection well is made of iron material, and is treated with anticorrosion, installed in sections, densely covered with multiple drainage holes, and a non-woven filter layer is attached outside; the bottom box of the water collection well is a hollow box shape, impermeable, The top is open, and the submersible pump and drainage pipeline are installed inside; the bottom end of the sump well connection is sealed and installed on the bottom box of the sump well, and the drainage pipeline is led out of the sump well connection, thus forming the drainage system of the sump well.

In the above technical scheme, the silt soil in the geomembrane bag is collected from the weak soil in the construction site, which is more convenient, economical and environmentally friendly; when filling the silt soil, a silt drop reagent can be added according to the soil properties to accelerate the silt drop, If the one-time filling degree is insufficient, it can be filled in two times to meet the layer thickness requirements; according to the increase in soil strength, it usually takes 3 to 7 days to lay the upper layer of three-dimensional composite drainage network and geomembrane bag.

The subgrade reinforcement structure formed during the above construction process: a working cushion is laid on the raw mud surface, and multiple layers of membrane bags filled with silty soil are successively laid on the working cushion, and a three-dimensional composite layer is arranged between each membrane bag layer. Drainage net; Lay sand layer on the film bag layer of the top layer, be equipped with vertical plastic drainage board below the sand layer, the bottom of plastic drainage board goes deep into the base of dredging and filling soil, and the head of plastic drainage board (12) is buried in the sand In the layer (11), a water collection well is vertically arranged in the film bag layer, the three-dimensional composite drainage network and the sand layer; a mountain soil structure layer is laid on the sand layer, and a heap load bearing layer is laid on the mountain soil structure layer.

Advantage of the present invention and beneficial effect are:

1. In the process of laying the film bag layer, the three-dimensional composite drainage network between the film bag layers is used as the horizontal drainage channel. After the film bag layer is compressed, the water in the muddy soil inside is discharged, and the discharged water flows along the three-dimensional The composite drainage network is collected horizontally to the inside of the water collection well, and then the water in the water collection well is discharged by the submersible pump, thereby rapidly reducing the water content of the silty soil in the film bag layer, and forming a preliminary hard roadbed structure on the upper layer of the dredger fill soil;

Then, lay a deep plastic drainage board, lay a sand layer, and apply pressure to the film bag layer and the blown fill soil foundation by setting an overload preload to further promote the drainage of the filled silt soil moisture in the film bag and the blown fill soil. Drainage of foundation moisture; when draining, the plastic drainage board is used as a vertical drainage channel, and the water in the filled soil foundation and the water in the muddy soil will enter the plastic drainage board, and the water in the plastic drainage board is collected horizontally through the sand layer and the three-dimensional composite drainage network To the inside of the water collection well (because the horizontal drainage channel of the three-dimensional composite drainage network may be partially blocked due to the deep plastic drainage board, so a sand layer is set on the head of the plastic drainage board, and the sand layer is used as a horizontal drainage channel to ensure plastic drainage. The water in the slab is collected laterally along the sand layer to the water collection well), and then the submersible pump is used to discharge the water in the water collection well, so as to realize the simultaneous reinforcement of the membrane bag layer and the deep dredged fill soil foundation.

2. The muddy soil in the geomembrane bag is collected from the weak soil in the construction site, which is more convenient, economical and environmentally friendly.

3. The water level of the water collection well is lowered, and the water level is located at the position of the three-dimensional composite drainage network at the bottom, which increases the effective stress of the soil in the filled membrane bag and the soil of the lower foundation, and increases the effective reinforcement load.

4. By filling the geomembrane bag with silty soil, the film bag effectively cuts off the water supplement channel and reduces the adverse effects of the surrounding water on the soil in the filled film bag.

5. When the three-dimensional composite drainage network collects and drains water under the filled membrane bag, it can use the gravity of the water to promote water collection (that is, the water in the soil in the membrane bag flows downward into the three-dimensional composite drainage network due to its own gravity), which is different from the traditional prefabricated drainage network. It is necessary to overcome the self gravity of the water when pressing on the drainage.

6. The construction method of the present invention can be directly constructed on the dredged fill soil foundation, and has good adaptability.

Description of drawings

Fig. 1 is a schematic diagram of the road structure of the present invention.

FIG. 2 is a partially enlarged schematic diagram of point A in FIG. 1 .

detailed description

The technical solutions of the present invention will be further described below in conjunction with specific embodiments.

Referring to accompanying drawing 1-2, a kind of construction method of constructing road on dredging fill foundation, it may further comprise the steps:

Step 1: Drain the accumulated water on the surface, lay brambles or bamboo fences or netted bamboo rafts on the original mud surface (0) as the foundation work cushion (1), place the bottom box of the water collection well (2) according to the well position of the water collection well, and Vertically install the sump connecting pipe (3);

Step 2: laying a layer of geotechnical non-woven fabric (4) on the working cushion (1), and making the water collection well connecting pipe (3) pass through the reserved sleeve (5) of the geotechnical non-woven fabric;

Step 3: Lay a layer of three-dimensional composite drainage network (6) on the geotextile non-woven fabric (4), and make the water collection well connecting pipe (3) pass through the reserved sleeve (7) of the three-dimensional composite drainage network (6);

Step 4: Lay a layer of geomembrane bag (8) on the three-dimensional composite drainage network (6), then fill the first layer of muddy soil (9) into the first layer of geomembrane bag (8); After the first layer of silt (9) is consolidated to form a certain strength, then repeat steps 3 and 4, continue to lay a new layer of three-dimensional composite drainage network 6 and geomembrane bag laying, and fill with muddy soil until the construction reaches the predetermined level. Set the top elevation;

Step 5: Lay a layer of geotechnical non-woven protective layer (10) on the topmost geomembrane bag, ensure that the non-woven protective layer (10) covers the entire base surface, and embed its edge into the soil;

Step 6: Lay a sand layer (11) on the non-woven protective layer (10), and then set up a vertical plastic drainage board (12), the bottom of the plastic drainage board goes deep into the dredging and filling soil base, and the plastic drainage board (12) The board head is buried in the sand layer (11);

Step 7: laying the mountain soil structure layer (13) on the sand layer (11);

Step 8: Lay the heap load (14) layer by layer on the mountain soil structure layer (13), and drain the water collection well; when the deformation conditions meet the engineering requirements, remove the heap load (14) and stop the water collection well drain;

Step 9: backfill the water collection well or take out the water collection well, build a masonry shoulder (15) on the mountain soil structure layer (13), and construct the road base (16) and road surface (17), and the road structure is completed.

In this embodiment, the compressive strength of the three-dimensional composite drainage network is not less than 14KN/m, the hydraulic conductivity is not less than 1/m/s, the thickness is not less than 6mm, the diameter of the sleeve is 60cm, and the length is 60cm. It is wrapped with geotechnical non-woven fabric , and tied with rubber bands;

The connection pipe of the water collection well is made of iron material, and it is anti-corrosion treated. It is installed in sections. The wall of the connection pipe of the water collection well is densely covered with multiple drainage holes. The bottom box of the water well is a cavity box-shaped body with a height of 65cm, which is impermeable and open at the top, and is equipped with a submersible pump and drainage pipeline inside; The water well is connected to form a water collection well drainage system;

The geomembrane bag is sewn by the split silk geotextile, using the overlock or slit method, the breaking strength is not less than 20kN/m, and the vertical permeability parameter is not less than 10 ^-3 cm/s;

The silt soil in the geomembrane bag is collected from the weak soil in the construction site, which is more convenient, economical and environmentally friendly; when filling the silt soil, you can add silt silting reagents according to the soil properties to speed up silting, if the filling degree is insufficient , can be filled in two times to meet the layer thickness requirements; according to the increase in soil strength, it usually takes 3 to 7 days to lay the upper layer of three-dimensional composite drainage net and geomembrane bag;

The geotextile non-woven fabric is 200g/m ² , the sleeve diameter is 60cm, and the length is 60cm;

The heap load is made of mountain soil with a height of 3m. The unloading standard is that the estimated settlement after construction is not greater than 30cm, and the settlement observed for two consecutive months does not exceed 5mm/month;

The thickness of the sand layer is 30cm;

The slope slope of the final road structure should be 1:1;

The pavement base is cement stabilized material.

The foundation reinforcement principle of the above construction method is as follows:

In the process of laying the film bag layer, the three-dimensional composite drainage network between the film bag layers is used as the horizontal drainage channel. The composite drainage network is collected horizontally to the inside of the water collection well, and then the water in the water collection well is discharged by the submersible pump, thereby rapidly reducing the water content of the silty soil in the film bag layer, and forming a preliminary hard roadbed structure on the upper layer of the dredger fill soil;

Then, lay a deep plastic drainage board, lay a sand layer, and apply pressure to the film bag layer and the blown fill soil foundation by setting an overload preload to further promote the drainage of the filled silt soil moisture in the film bag and the blown fill soil. Drainage of foundation moisture; when draining, the plastic drainage board is used as a vertical drainage channel, and the water in the filled soil foundation and the water in the muddy soil will enter the plastic drainage board, and the water in the plastic drainage board is collected horizontally through the sand layer and the three-dimensional composite drainage network To the inside of the water collection well (because the horizontal drainage channel of the three-dimensional composite drainage network may be blocked or collapsed due to the excessive pressure of the film bag layer, so a sand layer is set on the head of the plastic drainage board, and the sand layer is used as a horizontal drainage channel to ensure The water in the plastic drainage board collects horizontally along the sand layer to the water collection well), and then uses the submersible pump to drain the water in the water collection well, so as to realize the simultaneous reinforcement of the film bag layer and the deep filling soil foundation.

The present invention has been described as an example above, and it should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacements that can be made by those skilled in the art without creative labor all fall within the scope of this invention. protection scope of the invention.

Claims (4)

1. a kind of fill the construction method that mud bag builds road on reclaimed ground, it is characterised in that comprises the following steps：

Step one：Surface pond is discharged, working cushion layer based on chaste tree basketry or bamboo sheathing or netted bamboo raft is laid on former mud face (0) (1) sump under casing (2), and vertically-mounted sump adapter (3), are laid according to sump well location situation；

Step 2：One layer of geotechnological non-woven fabrics (4) is laid on working cushion layer (1), and sump is taken over (3) and passes through geotechnological nonwoven The reserved sleeve (5) of cloth；

Step 3：One layer of three-dimensional composite drainage network (6) is laid on geotechnological non-woven fabrics (4), and sump is taken over (3) and passes through three Tie up the reserved sleeve (7) of composite drainage network (6)；

Step 4：One layer of geomembrane bag (8) is laid on three-dimensional composite drainage network (6), then into first layer geomembrane bag (8) Fill first layer muck soil (9)；Sump carries out draining, after first layer mud (9) consolidation forms some strength, Ran Houchong Multiple step 3 and step 4, proceed new one layer three-dimensional composite drainage network laying 6 and geomembrane bag laying, and fill Muddy Bottoms Soil, until constructing to default top mark eminence；

Step 5：The geotechnological non-woven fabrics overcoat (10) of one layer of laying on top geomembrane bag, it is ensured that non-woven fabrics overcoat (10) whole basal plane is covered, and by its edge embedded soil body；

Step 6：Layer of sand (11) is laid on non-woven fabrics overcoat (10), vertical plastic draining board (12), plastic row is then set Water plate bottom is deeply to reclaimed ground layer, and plastic draining board (12) wrench is buried in layer of sand (11)；

Step 7：Mountain skin soil structure layer (13) is laid on layer of sand (11)；

Step 8：Preloading load (14) is successively laid on mountain skin soil structure layer (13), and carries out sump draining；Work as modified strip By preloading load (14) removal when part meets engineering demand, stop sump draining；

Step 9：Slope shoulder (15), and sub-surface of constructing (16) and top course are built in construction by laying bricks or stones on mountain skin soil structure layer (13) (17), road structure is completed.

2. according to claim 1 fill the construction method that mud bag builds road on reclaimed ground, it is characterised in that：Collection Well adapter is ferrous material, and carries out preservative treatment, and merogenesis is installed, and gather multiple draining holes, outer attached non-woven fabrics filtering layer；Collection Well under casing is cavity box-like body, and waterproof, top is open, and inside sets immersible pump and discharge pipe line；Sump takes over bottom It is sealingly mounted on sump under casing, and discharge pipe line is drawn into sump adapter, so as to constitutes sump drainage system.

3. according to claim 1 fill the construction method that mud bag builds road on reclaimed ground, it is characterised in that：Soil Muck soil in work film bag is gathered from local weak soil of constructing；When filling muck soil, mud is added according to soil nature and falls to become silted up Reagent, accelerates to fall to become silted up；According to soil strength growth pattern, by carry out within 3 days~7 days the three-dimensional composite drainage network laying of last layer and Geomembrane bag laying.

4. a kind of subgrade strengthening that mud bag builds the construction method formation of road is filled on reclaimed ground described in claim 1 Structure, it is characterised in that：Laid on former mud face and be equipped with multilayer on working cushion layer, working cushion layer successively filled with muck soil Film bag layer, and each film bag layer between be provided with three-dimensional composite drainage network；Layer of sand, layer of sand are laid on the film bag layer of top Vertical plastic draining board has been set below, and plastic draining board bottom is deeply to reclaimed ground layer, plastic draining board (12) wrench It is buried in layer of sand (11)；Sump is vertically arranged with film bag layer, three-dimensional composite drainage network, layer of sand；Mountain is laid on layer of sand Laying preloading load layer on skin soil structure layer, mountain skin soil structure layer.