帮东河水库大坝趾板固结灌浆试验施工技术分析

Analysis of Construction Technology for Consolidation Grouting Test of Toe Plate of Bangdonghe Reservoir Dam

以帮东河水库混凝土面板堆石坝为例,进行了现场固结灌浆试验,对试验灌浆效果进行分析评价,为正式生产固结灌浆提出符合规范标准的施工参数。结果表明:在灌浆前压水试验过程中,出现压入流量为70 L/min~90 L/min,孔口未反水,建议采用1∶1浆液进行开灌。该区内地下岩层较为松散、有大量裂隙、透水率高;设计灌浆压力作用下,压水试验(0.24 MPa)、灌浆过程中(0.3 MPa)趾板无抬动现象,可适当提高灌浆压力。此次试验灌浆效果较好,但耗浆量较大,建议就地取材掺入黏土或粉煤灰,降低成本,提高经济效益。试验孔经二次序钻灌大透水率明显降低,检查孔透水率合格,同样表明灌浆压力可适当提高。建议正式灌浆压力由原设计值0.3MPa提升至0.35MPa或0.4MPa,增加灌浆扩散范围,提升固结灌浆质量。对2个检查孔进行弹性波速质量检查,检测结果达标。

Taking the concrete face rockfill dam of Bangdonghe Reservoir as an example,on-site consolidation grouting tests were conducted to analyze and evaluate the grouting effect,and to propose construction parameters that comply with regulatory standards for the formal production of consolidation grouting.The results show that during the pre-grouting water pressure test,the injection flow rate was between 70 L/min and 90 L/min,and there was no backflow at the orifice.It is recommended to use a 1:1 slurry for grouting.The underground rock layers in this area are relatively loose,with a large number of cracks and high permeability.Under the designed grouting pressure,there is no lifting phenomenon of the toe board during the water pressure test(0.24 MPa)and grouting process(0.3 MPa),and the grouting pressure can be appropriately increased.The grouting effect of this experiment is good,but the slurry consumption is relatively high.It is recommended to mix clay or fly ash locally to reduce costs and improve economic benefits.The permeability rate of the test hole significantly decreased after drilling and grouting in two orders,and the permeability rate of the inspection hole was qualified,which also indicates that the grouting pressure can be appropriately increased.It is recommended to increase the formal grouting pressure from the original design value of 0.3 MPa to 0.35 MPa or 0.4 MPa,increase the grouting diffusion range,and improve the quality of consolidation grouting.Two inspection holes were subjected to elastic wave velocity quality inspection,and the test results met the standards.