微型桩杆塔基础水平承载力试验研究

通过现场真型试验,对微型桩基础的水平承载力进行研究。试验研究表明:二次注浆工艺有利于提高微型桩水平承载力,当采用投石注浆成桩时,应用于输电线路工程的微型桩必须采用二次注浆工艺;二次注浆工艺对微型桩水平承载力的提升作用因上部土层性质而异,尚需更多的试验和实践确定不同土层性质下二次注浆对微型桩水平承载力的提升效果;适当在微型桩群桩中布置一定的斜桩有利于提高群桩的水平承载力,但应考虑斜桩施工困难会对施工工期产生影响;进行微型桩基础设计时宜按水平允许位移进行控制,在合理选用设计参数的情况下,可采用本文提供的设计方法进行微型桩基础水平承载力的初步设计。

EXPERIMENTAL STUDY ON HORIZONTAL BEARING CAPACITY OF MICROPILED FOUNDATION FOR TRANSMISSION TOWER

Field tests are done to study the horizontal bearing capacity of micropiled foundation for transmission tower.Study shows that the second grouting can increase the horizontal bearing capacity of micropiles,so micropiles used in transmission line must apply the second-grouting technology.The influence of second-grouting technology on horizontal bearing capacity of micropiles due to the nature of the upper soil layer,which need more tests and practices to ascertain.Setting inclined piles can increase the horizontal bearing capacity of micropile group,but which may influence construction plan;if the reasonable design parameters are chozen,the horizontal bearing capacity of micropile foundation could be calculated preliminarily by the design method in this paper.