石灰钉复合锚杆加固软弱边坡现场试验研究

In-situ Test Study on Weak Slope Reinforcement with Lime Nail Composite Anchors

为了进一步了解石灰钉复合锚杆新型支护结构的实用效果与价值,对其开展了现场实测试验.通过对试验结果的分析,进行了石灰钉周围土体力热变化规律的研究和新型结构承载性能的评价.试验结果表明:(1)石灰钉的设置对周围土体的温度、膨胀压力和孔隙水压力变化均产生显著的影响,在石灰钉的合理布置间距范围内,石灰钉布置间距越小,对土体膨胀压力、温度和孔隙水压力的影响越显著,土体的固结速率越大;(2)与普通锚杆相比,石灰钉复合锚杆的抗拔承载力有明显的提高,在石灰钉的合理布置间距范围内,石灰钉布置间距越小,石灰钉复合锚杆的抗拔承载力越大.利用所采集的实测数据,对石灰钉周围土体的温度增量、膨胀压力和水平进深对孔隙水压力的影响进行了多元回归分析,并得到了合理的回归模型.分析结果表明:石灰钉周围土体的膨胀压力、温度增量和水平进深均对土体的孔隙水压力影响显著,膨胀压力和温度增量对孔隙水压力不仅存在线性影响,还存在非线性影响和交叉影响,而水平进深对孔隙水压力仅存在线性影响.

In order to further understand the practical effect and value of the lime nail composite anchor,a new type of support structure,the in-situ test was conducted.Based on the analysis of the test results,the rule of mechanical and thermal variation in the soil around lime nails and the evaluation of the bearing capacity of the new structure are carried out.The test results show that:(1)The setting of lime nails has a significant effect on the temperature,expansion pressure and pore water pressure of the surrounding soil.Within the reasonable spacing range of lime nails,the smaller the spacing of lime nails,the more significant the effect on the expansion pressure,temperature and pore water pressure of the soil,and the greater the consolidation rate of the soil;(2)Compared with ordinary bolts,the uplift bearing capacity of lime nail composite bolts has been significantly improved.Within the reasonable spacing range of lime nails,the smaller the spacing of lime nails,the greater the uplift bearing capacity of lime nail composite bolts.Based on the collected measured data,the influence of the temperature increment,expansion pressure and horizontal depth of the soil around the lime nail on the pore water pressure is analyzed by multiple regression,and a reasonable regression model is obtained.The analysis results show that the expansion pressure,temperature increment and horizontal depth of the soil around the lime nail have a significant influence on the pore water pressure of the soil,the expansion pressure and temperature increment not only have linear influence on the pore water pressure,but also have non-linear influence and cross influence,while the horizontal depth has only linear influence on the pore water pressure.