为进一步研究复杂环境下复合土钉墙的施工技术措施,以微型桩预应力锚杆复合土钉支护结构为研究对象,运用ABAQUS进行数值模拟,得出开挖过程中的侧向变形、坑底隆起和地表沉降曲线及土钉(锚杆)轴力图,并据此提出环境保护技术。分析结果表明:(1)随着开挖深度的增加,侧向位移向基坑内凸起,呈"鼓肚"形,最大位移出现在0.7倍开挖深度附近;(2)坑底隆起量由坡脚位置向基坑中部逐渐增加,中部隆起量最大,坡脚隆起量较小;(3)坑外地表沉降呈"勺"状,沉降的最大值发生在桩后1.4倍开挖深度附近;(4)微型桩的设置使得锚杆轴力降低幅度很大,最大值约62.16%;(5)"动态化设计"与"信息化施工"可以监测与指导复杂环境下复合土钉支护结构的设计和施工。
To investigate the construction technology of composite soil nailing wall in complex environment,a micropile prestressed anchor soil nailing compound structure( MPASNCS) was studied,and the curves of lateral deformation,bottom rebound and surface settlement including the axial forces of soil nails and anchor in digging were given by ABAQUS. In addition,measures of environment protection were proposed. The results shows that lateral deformation bulges to internal foundation,and that the maximum value appears near 0. 7 time of excavation depth. The bottom rebound increases gradually from the slope toe to the middle of foundation pit,the number of rebound at the middle is the maximum,and that at the slope toe is smaller. The surface settlement of exterior foundation shows the shape of a spoon,and the maximum settlement is located after 1. 4 time of excavation depth. The micropile reduces the axial forces of anchors a lot,and the maximum reduction runs up to 62. 16%. The dynamic design and information construction can monitor and guide the designand construction of composite soil nailing retaining structure in complex environment.