旋喷锚杆锚固体直径计算方法及影响参数试验研究

发布时间：2018-04-23 21:16

本文选题：旋喷锚杆 + 锚固体直径　；参考：《岩土工程学报》2016年10期

【摘要】：旋喷锚杆锚固体直径是影响锚杆抗拔力和可靠性的关键。基于高压旋喷破土扩孔的物理过程,提出一种便于实际应用的高压旋喷锚杆锚固体直径计算方法,并以三门核电站二期泵房32 m深基坑支护为背景,设计现场试验验证计算方法的实用性,通过将12根试验锚杆中的3根挖出,分析旋喷参数对锚固体直径的影响。结果表明:1受土体未被完全破碎和大颗粒土沉淀等因素的影响,旋喷锚杆锚固体直径的计算值比实测数据略小,喷射压力越小,钻进速度越快,计算值和实测数据之间的偏差越大;2钻杆螺旋运动和振动导致旋喷锚杆锚固体的形状近似为椭圆形,且表面有片状毛刺,喷射压力越大,钻进速度越快,锚固体的形状越不规则;3相同条件下,增大喷嘴直径和采用二次扩孔能够获得更好的成孔质量,为提高成孔工效,并防止出现射流剖面间断,应合理配置钻进速度。
[Abstract]:The Anchorage diameter of rotating shotcreting bolt is the key to affect its pullout resistance and reliability. Based on the physical process of high pressure rotary shotcrete breaking hole expansion, a method for calculating the Anchorage diameter of high pressure rotary shotcrete bolt is put forward, which is convenient for practical application, and is based on the 32 m deep foundation pit support of the second phase pump room of Sanmen Nuclear Power Station. Field test was designed to verify the practicability of the calculation method. By digging out 3 of the 12 test anchors, the influence of rotating shotcrete parameters on the Anchorage diameter was analyzed. The results show that the calculated value of the diameter of the bolt is slightly smaller than that of the measured data. The smaller the jet pressure, the faster the drilling speed, the smaller the jet pressure, the faster the drilling speed. The bigger the deviation between the calculated value and the measured data is, the larger the screw motion and vibration of the drill pipe lead to the shape of the anchor body is approximately elliptical, and the surface is burr, the higher the jet pressure is, the faster the drilling speed is. The more irregular the Anchorage body is, the better the hole forming quality can be obtained when the nozzle diameter is increased and the secondary reaming is adopted. In order to improve the hole forming efficiency and prevent the jet profile discontinuity, the drilling speed should be arranged reasonably.
【作者单位】：中国水利水电科学研究院;北京中水科工程总公司;
【基金】：中国水利水电科学研究院青年科研专项基金项目(1518)
【分类号】：TU476

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