弱面夹层岩质边坡合理锚注间距确定及实证

Determining proper bolting grouting spacing in rock slope with weak intercalation surfaces and the instance

岩土工程中的一类含弱面夹层岩质边坡的稳定加固最好采用锚注综合措施。该文以湖南某高速公路含弱面夹层岩质边坡为例,就其实施预应力锚管锚注加固时边坡岩体内预应力群锚锚固墙效应和注浆扩散效应进行了分析。提出了将二者结合确定合理锚注间距的实用计算方法及其正规化计算流程,并采用超声波检测验证了所定锚注间距的合理性。结果表明：针对本依托工程实际,弱面夹层岩质边坡采用预应力锚注方式加固时,若采用张拉力为100k N的预应力锚管,其锚注间距选为3 m较为合适,此时超声检测显示在离注浆锚固孔处1.9 m范围内的岩体,其纵波波速比未加固岩体要提高10%~33%。研究结论可为同类边坡工程的预应力锚注加固方案设计提供参考。

Bolting grouting comprehensive measures are better when we reinforce rock slope with weak intercalations in geotechnical engineering. Based on a case of rock slope with weak intercalations in highway of Hunan province,the effect of prestressed anchor wall and grouting diffusion was analyzed when prestressed anchor pipes were used in slope. The practical calculation method and normalized process of determining proper bolting grouting spacing was given. And this paper verified the rationality of bolting grouting spacing through ultrasonic detecting. The results were shown as follows： According to the actual parameter of rock slope,the bolting grouting spacing of 3 m was reasonable when prestressed anchor pipes of 100 k N were used in rock slope with weak intercalations. Meanwhile, the result of ultrasonic detecting showed that the compressional wave velocity was increased by 10% ~ 33% than without reinforcement within the grouting scope of 1. 9 m. The conclusion of this paper can provide the reference of similar slope which need scheme design of prestressed anchor reinforcement.