Composite pile-net structure subgrade with varied pile stiffness has the advantages of small settlement after construction and economic benefits and is widely used in railway engineering.Compared with the traditional pile-bearing structure embankment,the pile-soil cooperative work law of this structure is more complicated.To study its bearing characteristics and variation laws of soil settlement,this study adopts the laboratory model test and numerical calculation to analyze the pile stress,pile-soil stress ratio,geogrid stress,pile side molecular resistance and soil settlement variation characteristics of composite pile-net structure subgrade with varied pile stiffness under static load.The results show that the bearing capacity of rigid and flexible piles is mainly provided by side mechanical resistance;the pile-soil stress ratio of rigid piles shows a growing and then a stabilizing trend with the increase of upper load.The load is transferred from the center pile to the edge piles along the center pile in the embankment and spreads along the embankment in the direction of traffic movement toward the embankment in the direction of the cross-section;the geogrid and the crushed stone reinforced bedding layer work together to coordinate with the redistribution of loads and to equalize the distribution of embankment stress;the soil settlement of the center pile rowing along the center pile of the embankment in the direction of cross-section is also improved.The soil settlement in the cross-section direction displays approximately a basin-shaped distribution,and the rigid piles controlling the deformation and settlement of the soil of the embankment is significantly better than the flexible piles;the selective arrangement of longer piles with larger stiffness can reduce the settlement of subgrade.
关键词
路基/刚度差异桩/桩网结构/承载特性/模型试验/数值计算
Key words
Subgrade/Piles with different stiffness/Pile-net structure/Bearing characteristics/Model test/Numerical calculation
维普
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