增大击实功的路基压实试验研究

Experimental Research for Subgrade Compactness Effect of Increased Compaction Energy

压实度是路基填筑时控制路基强度和稳定性的关键指标。通过室内试验研究了击实功对路基压实度的影响。结果表明增大击实功,路基土的最大干密度和7 d无侧限抗压强度都有显著提高,抗压强度最大增幅达到50%左右。因此增加路基土的密实度,可以明显地提高路基土的强度,延长路基的使用寿命。还通过现场试验研究了压实机具和碾压遍数对压实度的影响,并采用便携式落锤弯沉仪(PFWD)对压实后的路基强度进行检测。结果表明随碾压遍数的增加,压实度存在一定的增大趋势,但对不同材料的路基应选用不同的机具组合、碾压遍数等,以保证压实效果最佳。总之,由于目前重型压实机械的普遍使用,为更好地控制压实质量,适当提高路基压实标准势在必行。

The compactness is the key index of the intensity and stability control of subgrade during the building of subgrade.The effect of compaction energy on compactness is studied by indoor experiments.The results indicate that the maximum dry density and the 7-day unconfined compressive strength obviously increase along with the increase, of compaction energy. Especially the maximum growth of the compressive strength is about 50% .Therefore if the density of subgrade can be improved effectively, the strength of subgrade can be enhanced and the life of pavement can be prolonged. In addition, the effect of compaction machine and the number of compaction run on the compactness is discussed based on the in-situ test, using the PFWD to test the strength of subgrade after compaction.The results indicate that the compactness is increased with the increase of compaction run. In order to reach the best compaction effect, different material subgrade should choose, different compaction machine combination and different the number of compaction run. Because the heavy, compaction machine is used widely and to get better control of the compaction quality, it is necessary to improve the compaction standard.