灌注细石混凝土微型桩基础下压试验研究

摘要

通过现场真型试验,对灌注细石混凝土成桩微型桩基础抗压承载机理及其抗压承载力计算方法进行了研究.试验表明:本次试验条件下,微型桩单桩可看成纯摩擦桩进行抗压承载力计算；微型桩群桩在极限下压荷载作用下,承台底部土体承担荷载比例仅为4.8％,在进行微型桩群桩抗压极限承载力计算时可不考虑承台底土的承载作用；由于承台对下压荷载的重分配,在下压荷载作用下,角桩承力最大,边桩次之,中桩最小；本次试验条件下,微型桩抗压群桩效应系数可取0.8进行计算.%In (his paper, field tests were done to study the compressive bearing mechanism and compressive design method of micropiles. Study shows: in this experimental condition, single micropile can be regarded as friction pile to calculate the compressive bearing capacity; under the ultimate load, the bearing ratio of the soil under the cap of micropile group is only 4. 8% , so calculating the compressive bearing capacity of micropile group cannot take into account the role of subsoil bearing; under compressive load, the bearing load of the angle pile is maximum, the side pile is the second, and the middle pile is minimum; in this experimental condition, the compressive pile group effect coefficient is 0. 8.