高压旋喷锚杆的试验研究

Test Study on High-pressure Rotary Jet Grouting Bolt

本文结合天津市滨海新区某文化广场工程,在软土地质条件下,基坑采用钢筋混凝土桩加高压旋喷锚杆进行围护的施工工艺,需进行可行性试验。试验方法遵循《建筑基坑支护规程》(JGJ120-2012)中的规定,通过选用的5根锚杆进行试验数据分析。高压旋喷锚杆的锚固段强度较低,易造成锚杆的弹性变形较小,塑性变形较大,且蠕变系数偏大,因此,在软土地区采用高压旋喷锚杆工艺时,为满足锚固力需求,应加长锚固段的长度,并在原施工工艺中做部分改进,才能达到在软土地区应用高压旋喷锚杆的目的。

Based on the engineering of a Cultural Plaza of Binhai New Area in Tianjin,it is a kind of construction process in soft soil in which the foundation pits are supported by reinforced concrete piles and high-pressure jet grouting anchor bolts.Since it is the first time that high-pressure jet grouting anchor bolts are applied in soft soil,some kinds of feasibility experiments are necessary.The methods used in the experiment adhere to national rules in JGJ120-2012.According to experimental statistics analysis from 5 anchor bolts,as the strength of anchorage segment in the high-pressure jet grouting anchor bolt is relatively low,the bolt is usually with small elastic deformation and big plastic deformation,and the creep factor is too high.So,when applying high-pressure jet grouting anchor bolts to soft soil,in order to generate enough anchorage force,the anchorage segment should be lengthened and other improvements in the construction process should be made.