Aeolian sand subgrade construction method

Abstract

The invention provides an aeolian sand subgrade construction method. The method comprises the following steps that surveying and setting out are conducted; a base layer is laid; padding is loaded and unloaded; a reinforcing layer is laid; a reinforcing layer is laid on the surface of aeolian sand, wherein the reinforcing layer comprises limestone, polypropylene fibers, loose filling and the balance coal ash; tilling is conducted, specifically, watering is conducted on the reinforcing layer, and tilling is conducted on a subgrade multiple times in the length direction; riffle watering is conducted; rolling compaction is conducted through a bulldozer; rolling compaction is conducted through a road roller; compaction detection is conducted, specifically, the compaction coefficient Kof the compacted aeolian sand is detected in a sand filling mode or a water filling mode; and the step that padding is loaded and unloading to the step that compaction detection is conducted are conducted repeatedly until the subgrade reaches a design elevation, and construction is completed. According to the aeolian sand subgrade construction method provided by the invention, the reinforcing layer is laid on the aeolian sand, the reasonable rolling compaction mode is adopted, the strength of the vibrated and compacted subgrade meets design requirements, the compressive strength is high, the failure strain resistance and tension resistance of the subgrade are greatly improved, and the stability of the subgrade is improved.

Description

technical field [0001] The invention relates to a construction method of a highway subgrade, and more specifically relates to a construction method of an aeolian sand subgrade. Background technique [0002] Aeolian sand is produced by sand being moved to the alluvial plain area by wind-blown sand flow to form sand dunes. It has the characteristics of loose structure, poor gradation, large porosity, low strength, good water stability, uniform settlement, and less affected by unfavorable seasons. To build roadbeds in desert areas, if ordinary cohesive soil is to be used, it needs to be transported from a distance, which is not only difficult to obtain soil, but also greatly increases the project cost and prolongs the construction period. In line with the principle of obtaining local materials and reducing project cost, it is of course best to use aeolian sand that can be obtained locally as the main filler for filling the roadbed. Because aeolian sand is in a loose state und...

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Problems solved by technology

Because aeolian sand is in a loose state under natural conditions, its cohesion is basically zero, and its shear resistance is poor and shear expansion occurs. Therefore, there are the following problems when using aeolian sand as the main filler for filling roadbeds: First, it is not easy to compress Actually, the compaction of aeolian sand generally adopts the method of vibratory compaction. If the pressure is insufficient or the excitation force is insufficient, the compaction effect will be poor and the design requirements cannot be met; During vibratory compaction, too large excitation force or too long action time of excitation force will not only increase the compactness, but also make the aeolian sand looser. If it is aeolian sand with uneven particle size distribution, it will also appear The stratification phenomenon in which large particles are in the lower layer and small particles are in the upper layer; and the roadbed or embankment made of this material is easy to deform or lose stability during use, especially it is more difficult to use soft aeolian sand as embankment engineering , difficult to compact and severely deformed

The second is poor stability. The subgrade or embankment made of this material is easy to deform or lose stability during use, and the compressive capacity is not strong. Especially, it is more difficult to use soft aeolian sand as an embankment project, and it is difficult to compact and severe deformation

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