氡(RaA)测试技术在某岩质边坡卸荷深裂缝带研究中的应用

FD-307RaA测氡仪，是一种新型的瞬时测氡仪器，它由抽气泵和测量操作台两部分组成，利用静电收集RaA作为测试对象，定量测试地质体中氡的浓度。某水电站坝址左岸岸坡正常卸荷带深部以内发育有一系列规模不等的深裂缝，对水工布置和工程边坡稳定将产生不利的影响，成为该坝址最突出的工程地质问题。本次对该水电站左岸边坡的PD44等9个平硐进行了氡测试，验证和预测深裂缝的空间发育和分布情况。并对测试的氡气浓度数据进行整理、统计和分析。氡气浓度值沿硐深的变化是有规律的，氡气异常与深裂缝带在空间上具有较好的对应关系，氡气高值往往对应于深裂缝产出部位，而低值带往往对应于岩体完整、深裂缝不发育的部位。并且氡气值与声波波速也有对应关系，声波波速高的地带，岩体质量好，对应氡浓度较低；在声波波速低的地带，岩体质量差，对应的氡气测试值高。氡测试技术可以作为评价平硐硐壁岩体破碎情况的一种新方法，同时可以用来预测前方的岩体质量。作为一种新的方法，有它自身的优缺点。

The application of RaA testing technique on researching deep fracture belts in a rock-slope

FD-3017RaA is a new instrument testing RaA, which has two parts, one is pump, and the other is operation platform. It uses the electrostatic method to collect RaA as the object for measureing the density of RaA. There are some deep fractures at a hydroelectric station's left bank, which affect the hydraulic architecture and the stability of the slope and become the most emergent problem of the hydroelectric project. In order to verifying and forecasting the distribution of the deep fractures we tested the density of Radon in 9 exploration tunnels.It indicates that the Radon density changes regularly along the depth of the tunnels. Where there are some deep fractures, the rock quality is bad and the density of RaA is high. At the means time the data is corresponded with the sonic data. Where the sonic data is high, the rock's quality is good, and where the density of RaA is low, the quality is bad. So RaA measurement is a new method used in asserting the degree of the rock's breakage and forecasting the quality of the rock's ahead. As a new method it has its own merits and drawbacks.