阅读说明：本技术 一种软土路基处置方法 (Soft soil roadbed disposal method ) 是由 刘超 申时国 于 2021-11-09 设计创作，主要内容包括：本发明涉及一种软土路基处置方法,将路基沿线软土层开挖到设计换填深度后,铺设下层防渗土工布；在下层防渗土工布上铺设两层铅丝网,在铅丝网上按路基设计宽度铺设一定厚度的片石层,然后用铅丝网将片石层两侧、两端及顶面完全包裹,形成裹紧片石层的铅丝笼；在铅丝笼顶面铺设上层防渗土工布；在上层防渗土工布上用换填土填筑到路基设计高度,并铺筑路面结构层。本发明适用于较厚软土层的路基施工,能减少路基软土换填深度,加快施工进度,并保证路基整体稳定性。(The invention relates to a soft soil roadbed disposal method, which comprises the steps of excavating a soft soil layer along a roadbed to a designed filling depth, and paving lower-layer anti-seepage geotextile; laying two layers of lead wire nets on the lower anti-seepage geotextile, laying a flaky stone layer with a certain thickness on the lead wire nets according to the designed width of the roadbed, and then completely wrapping two sides, two ends and the top surface of the flaky stone layer by using the lead wire nets to form a lead wire cage tightly wrapping the flaky stone layer; laying upper-layer impermeable geotextile on the top surface of the lead wire cage; and filling the upper anti-seepage geotextile to the designed height of the roadbed by using the replacement filling soil, and paving a road surface structure layer. The invention is suitable for the roadbed construction of a thick soft soil layer, can reduce the roadbed soft soil replacement depth, quickens the construction progress and ensures the overall stability of the roadbed.)

1. A soft soil roadbed disposal method is characterized by comprising the following steps:

(1) excavating a soft soil layer along the roadbed to a designed replacement depth, and paving a lower anti-seepage geotextile layer;

(2) laying two layers of lead wire nets on the lower anti-seepage geotextile, laying a flaky stone layer with a certain thickness on the lead wire nets according to the designed width of the roadbed, and then completely wrapping two sides, two ends and the top surface of the flaky stone layer by using the lead wire nets to form a lead wire cage tightly wrapping the flaky stone layer;

(3) laying upper-layer impermeable geotextile on the top surface of the lead wire cage;

(4) and filling the upper anti-seepage geotextile to the designed height of the roadbed by using the replacement filling soil, and paving a road surface structure layer.

2. A soft soil subgrade treatment method according to claim 1, characterized in that: in the step (1), after the soft soil layer is excavated to the designed replacement and filling depth, a gravel layer with a certain thickness is replaced and filled, and then the lower anti-seepage geotextile is laid on the gravel layer.

3. A soft soil subgrade treatment method according to claim 2, characterized in that: the thickness of the gravel layer is 0.8-1.2 m.

4. A soft soil subgrade treatment method according to claim 1, characterized in that: in the step (2), the flaky stone layer is laid manually, the degree is at least 2m, and the size of the adopted flaky stone is not more than 30 cm.

5. A soft soil subgrade treatment method according to claim 4, characterized in that: two sides of the lamella layer are wrapped by three or more than three lead wire meshes.

6. A soft soil subgrade treatment method according to claim 5, characterized in that: the lamellar stone layer is laid in two or more layers, each layer is independently wrapped by a lead wire cage, and the upper impermeable geotextile is laid on the topmost lead wire cage.

7. A soft soil subgrade treatment method according to claim 1, characterized in that: when the design height of the roadbed is higher than the original ground line, the rubble layer is laid above the ground line according to the design slope-laying width of the roadbed.

Technical Field

The invention relates to the technical field of road construction, relates to the construction of a road subgrade, and particularly relates to a soft soil subgrade disposal method.

Background

Soft soils are characterized by high water content, poor permeability, low natural strength and high compressibility, and are widely found in rivers, lakes, coastal areas, basins and rainy mountain depressions. When the road construction is carried out in the areas, if the soft soil in the roadbed exceeds the critical height, the defects of road surface collapse, cracking and the like are easy to generate, so that the defects of soft soil roadbed in the road construction are solved, the conventional method is to remove and replace the filling, but in the areas with thick soft soil layers, the filling is difficult to replace the bottom of the soft foundation, the stability of the roadbed after the filling cannot be ensured, the filling construction cost is high, and the construction period is long.

Disclosure of Invention

The invention aims to solve the problems, and provides a soft soil roadbed disposal method which can improve the construction speed and enhance the roadbed stability when a soft soil layer is thick, the roadbed disposal is difficult to meet due to replacement and filling, and the construction period is short.

The technical scheme of the invention is as follows:

a soft soil roadbed disposal method is characterized by comprising the following steps:

(1) excavating a soft soil layer along the roadbed to a designed replacement depth, and paving a lower anti-seepage geotextile layer;

(2) laying two layers of lead wire nets on the lower anti-seepage geotextile, laying a flaky stone layer with a certain thickness on the lead wire nets according to the designed width of the roadbed, and then completely wrapping two sides, two ends and the top surface of the flaky stone layer by using the lead wire nets to form a lead wire cage tightly wrapping the flaky stone layer;

(3) laying upper-layer impermeable geotextile on the top surface of the lead wire cage;

(4) and filling the upper anti-seepage geotextile to the designed height of the roadbed by using the replacement filling soil, and paving a road surface structure layer.

The method is suitable for roadbed construction of a thick soft soil layer, can reduce the roadbed soft soil replacement depth, quickens the construction progress, solves the problems of large replacement engineering amount, long construction period and poor roadbed quality when the soft foundation layer is thick, and ensures the overall stability of the roadbed; when the roadbed exceeds the original ground, the land occupation of slope relief and the filler waste can be reduced.

Drawings

FIG. 1 is a schematic cross-sectional view of a subgrade in which the present invention is employed;

fig. 2 is a schematic longitudinal section of a roadbed employing the invention.

Detailed Description

As shown in fig. 1 and 2, the specific construction method of the present invention is as follows:

(1) and (4) designing the replacement and filling depth of the soft soil layer in advance according to the geological conditions of the constructed roadbed. And excavating the soft soil layer along the roadbed to the designed replacement filling depth, and paving the lower anti-seepage geotextile 1. The lower anti-seepage geotextile is laid at the bottom and two sides of the excavated soft soil layer.

After the soft soil layer is excavated to the designed replacement filling depth, lower anti-seepage geotextile can be directly paved on the lower soft soil layer according to the lower soft soil depth and the soil texture state; when the lower soft soil layer is still thick or the soil quality is loose, the gravel layer 2 with a certain thickness can be filled, and after compaction, the lower impermeable geotextile is laid on the gravel layer. The filling thickness of the gravel layer is 0.8-1.2 m.

(2) Laying two layers of lead wire meshes 3 on the lower anti-seepage geotextile, laying a flaky stone layer 4 with a certain thickness on the lead wire meshes according to the designed width of the roadbed, and then completely wrapping two sides, two ends and the top surface of the flaky stone layer by using the lead wire meshes 3 to form a lead wire cage wrapping the flaky stone layer tightly.

In order to ensure the strength of the lead wire cage on the two sides of the roadbed, the two sides of the rubble layer are wrapped by three or more layers of lead wire nets.

During specific construction, the flaky stone layer is laid manually, the size of the adopted flaky stone is not more than 30cm, and the thickness of the flaky stone layer is at least 2 m.

When the lamellar layer that needs to lay is thick, can divide into two-layer or multilayer with the lamellar layer and lay, every layer adopts the lead wire cage to wrap up alone.

(3) Laying an upper impermeable geotextile 5 on the top surface of the lead wire cage; when the rubble layer is multilayer, the upper impermeable geotextile is laid on the topmost lead wire cage.

(4) And filling the upper anti-seepage geotextile with the replacement filling soil 6 to the designed height of the roadbed, and paving a pavement structure layer.

According to the construction method, when the design height of the roadbed is higher than the original ground line, the rubble layers are laid above the ground line according to the design slope-laying width of the roadbed. Meanwhile, the lamellar stone layer can be vertically paved on the ground line, so that the design slope-laying width of the roadbed can be correspondingly reduced.