短桩桩网复合地基荷载分担特征监测试验

Monitoring Test on Load Sharing Characteristics of Geogrid-reinforced and Short Pile-supported Composite Foundation

依托柳(州)南(宁)客运专线工程试验段,开展现场全尺寸监测试验,监测了短桩桩网复合地基在填筑期和放置期的地表桩土沉降和桩土应力变化。结果表明:在路基填筑过程中,桩顶和桩间沉降的地基表面沉降横向分布逐渐从“W”型趋向“^”型,最终分布比例趋于一致;桩土承担荷载比例逐渐降低,格栅承担荷载比例逐渐增大,路肩格栅增大比例大于中心处;桩土合力在横向上按“W”型分布,桩土应力比和桩土合力呈正比例关系,桩土合力增大,桩土应力比增长速率减缓。

Based on the experimental section of Liuzhou—Nanning passenger dedicated line project,full-size insitu monitoring tests have been carried out to monitor the settlement of pile and soil and the change of pile and soil stress of geogrid-reinforced and short pile-supported composite foundation during filling and curing periods.The results show that in the process of subgrade filling,the lateral distribution of foundation surface settlement of pile top and settlement between piles gradually changes from"W"type to"^"type,and the final distribution proportion tends to be consistent.The load bearing proportion of pile and soil decreases gradually,the load bearing proportion of grille increases gradually,and the increase proportion of grille on road shoulder is larger than that at the center.The pile-soil resultant force is distributed in a"W"shape at the transverse direction.The pile-soil stress ratio is proportional to the pile-soil stress ratio.With the increase of pile-soil stress ratio,the growth rate of pile-soil stress ratio slows down.