摘要
通过对注浆土体物理力学性质试验及对不同设计参数下普通注浆土钉和高压注浆土钉稳定性变化规律的计算对比,分析了土钉间距、长度、倾角、钻孔直径对注浆土钉整体稳定的影响。分析结果表明:掺入水泥浆后土体的压缩模量显著提高,水泥注入量越高,抗剪强度和摩擦力提高值越大。随着土钉水平间距的增大,高压注浆与普通注浆土钉整体稳定安全系数比β值呈现先增大后减小的趋势,土钉间距设计宜选取在各工况β值均最大的区间内。对高压注浆土钉长度的优化设计应考虑不同深度,深部应在土钉长度较长区域选取,浅部应在土钉长度较短区域内选取,这样区域内β值更大,注浆产生的效果最佳。土钉倾角对高压注浆土钉的整体稳定安全系数影响比普通注浆土钉要大,高压注浆土钉在浅部可采用较小倾角,而在中部、深部处适宜采用较大倾角,这样能够更好地发挥高压注浆对土钉整体稳定的作用。高压注浆时,应选择适宜的钻孔直径,钻孔直径过大或过小,都不能最大程度发挥高压注浆土钉的利用效率。
Based on the tests for the mechanical and physical properties of the grouting soil and on the stability variation calculation for the ordinary and high-pressure grouting soil nails with the different design parameters,the impact of the soil nailing level interval,length,inclination,borehole diameter on the overall stability of pressure grouting soil nail is analyzed. The analysis results show that,the compression modulus of cement mixed soil significantly increased,and the higher the cement content is,the larger the shear strength and friction increase are. With the increase of soil nailing level interval,the trend of safety factor of the stability of the high pressure and ordinary grouting soil nails is first increasing and then decreasing,soil nailing level interval design should be selected under the highest β range at any construction conditions. Optimization design of the high-pressure grouting soil nail length should consider the different depth,meanwhile,the length of the deep should be chosen in the longer region,otherwise,the shallow in the shorter region,much more,the grouting effect is the best in which area with an more appropriate β value. Comparing with the ordinary circumstance,the effect of the inclination towards safety factor of the stability of high-pressure grouting soil nail is bigger,and it is better to use a small angle of high-pressure grouting soil nail in the shallow area,but in the middle and deep place the large angle is better. Therefore,the high-pressure grouting soil nail plays an active role in the effect of overall stability.The drillhole diameter should be chosen carefully during the high pressure grouting,and it couldn't obtain the maximum utilization efficiency of high-pressure grouting soil nails with the hole diameter is either too large or too small.
出处
《工程勘察》
2014年第11期6-11,共6页
Geotechnical Investigation & Surveying
基金
浙江省教育厅科研项目资助(Y201330102)
关键词
土钉墙
高压注浆
设计参数
整体稳定
soil nailing wall
high pressure grouting
design parameter
overall stability
