土工格室加固砂基未铺路面APT试验研究

Accelerated Pavement Test Study of Geocell Reinforced Sand Base Unpaved Pavement

加速路面试验是在相关环境条件下通过施加受控车轮载荷来评价路面性能的一种有效方法。将四个未铺路面路段分为加固和未加固两部分进行加速路面试验。第1和第4部分是砂基,是在破坏后用骨料基替换的未加固部分。第2和第3部分是在骨料覆盖层下用新型聚合物合金(NPA)土工格室加固的砂层。在经过一定次数车轮碾压后,测量每个路段的车辙深度。用应变片监测NPA土工格室不同位置的水平应变。试验结果表明,NPA土工格室在改善未铺路面的稳定性和减少永久变形方面具有显著效果。在特定的试验条件下,土工格室加筋砂层的性能相当于相同厚度的A-1-a骨料,显示出保持土工格室结构完好无损对确保NPA土工格室加固基底的足够性能具有重要意义。最后的试验应变片测量显示,车轮路径下的NPA土工格室承受拉伸应力,而车轮路径外的土工格室承受压缩应力。

Accelerated pavement test is an effective method to evaluate pavement performance by applying controlled vehicle wheel load under relevant environmental conditions.In this paper,four unpaved road sections are divided into reinforced and unreinforced parts for accelerated pavement test.Part 1 and Part 4 are unreinforced sand base,replaced by aggregate base after damage.Part 2 and Part 3 are sand layers reinforced by a new polymer alloy(NPA)geocell under the aggregate cover.After a certain number of times of wheel rolling,the rut depth of each section is measured,and the horizontal strain at different positions of NPA geocell is monitored with strain gauges.The test results show that NPA geocell has significant effect on improving the stability of unpaved pavement and reducing permanent deformation.Under specific test conditions,the performance of the reinforced sand layer of the geocell is equivalent to A-1-a aggregate of the same thickness,which reveals that maintaining the integrity of the geocell structure is important to ensure the sufficient performance of the NPA geocell reinforced base.The strain gauge measurement of the final test shows that the NPA geocell under the wheel path bears tensile stress,while the geocell outside the wheel path bears compressive stress.