遵义市某小区复杂溶洞精细化探测及建模

Refined exploration and modeling of complex karst in a residential area of Zunyi City

摘要

【目的】随着西部大开发战略的实施，岩溶地质引起的地基力学特性降低问题逐渐显现，这对工程施工和人民的安全产生了不可忽视的影响。同时，复杂溶洞由于其隐蔽性，往往难以被准确探测到，这进一步增加了工程建设的风险。因此，建立以定性分析和定量分析相结合的探测方式准确探测和刻画溶洞。【方法】以遵义市某小区楼栋建设项目中溶洞探测为例，首先采用高密度电法进行场区探测，得到溶洞的走向、发育范围等资料。其次，利用3D激光扫描技术获取溶洞形态与三维空间分布详细数据。最后，将高密度电法探测结果和三维激光扫描结果进行比对分析。【结果】结果显示：从高密度电法反演结果可知溶洞走向为NNW-SSE,三维激光建模显示溶洞埋深从北向南逐渐变大，溶洞的总体积为2 795.48 m³,高度在0.5~8.57 m之间，宽度在1.97~23.34 m之间；对两种方法结合分析，得到溶洞平面位置偏差在0~18 m之间，偏差率为0%~112.5%,深度偏差在2~8 m之间，偏差率为8%~33.3%。【结论】结果表明：利用高密度电法结合三维激光扫描探测溶洞，从定性分析到定量描述，获得溶洞的埋深情况、高度变化和发展规模等信息，以及比对分析得到的偏差率，能对人为无法进入的溶洞进行标识，实现对复杂溶洞的精细化探测。可见，高密度电法和三维激光扫描方法结合，是溶洞精细化探测的一种有效的技术方法组合。

Abstract

[Objective] With the implementation of the strategy of large-scale development of the western region, the problem of reducing the mechanical properties of the foundation caused by karst geology has gradually emerged, which has had a non-negligible impact on the construction of the project and the safety of the people. At the same time, complex karst caves are often difficult to be accurately detected due to their concealment, which further increases the risk of engineering construction. Therefore, a combination of qualitative and quantitative analysis was established to accurately detect and characterize karst caves. [Methods] Taking the karst cave detection in a residential building construction project in Zunyi City as an example, firstly, the high-density electric method is used to detect the field area, and the data of the direction and development range of the karst cave are obtained. Secondly, 3D laser scanning technology was used to obtain detailed data of karst cave morphology and three-dimensional spatial distribution. Finally, the high-density electrical detection result and the 3D laser scanning result were compared and analyzed. [Results] The result show that the cave strikes NNW-SSE from the high-density electrical inversion result, and the 3D laser modeling shows that the buried depth of the cave gradually increases from north to south, and the total volume of the cave is 2 795.48 m³, the height is between 0.5~8.57 m, and the width is between 1.97~23.34 m. The combination analysis of the two method shows that the plane position deviation of the karst cave is between 0~18 m, the deviation rate is 0%~112.5%, and the depth deviation is between 2~8 m, and the deviation rate is 8%~33.3%. [Conclusion] The result show that the high-density electrical method combined with 3D laser scanning can be used to detect karst caves, from qualitative analysis to quantitative description, the information of the buried depth, height change and development scale of karst caves, as well as the deviation rate obtained by comparative analysis, which can identify karst caves that cannot be entered by humans, and realize the fine detection of complex karst caves. It can be seen that the combination of high-density electrical method and 3D laser scanning method is an effective combination of technical method for fine detection of karst caves.

关键词

复杂溶洞 / 高密度电法 / 三维激光扫描 / 精细化探测 / 三维激光建模 / 地下水 / 流量

Key words

complex karst cave / high density electrical method / three-dimensional laser scanning / fine detection / 3D laser modeling / grouhdwater / flow

基金资助

国家自然科学基金(42264008)

贵州省地矿局局管科研项目(黔地矿科合〔2019〕12 号)