贵州某机场场地岩溶发育特征及成因分析

通过对贵州某机场初步勘察资料的统计分析,探讨了整个场区的岩溶发育特征、分布规律以及成因机理。场区构造相对稳定,多发育揉皱、压性小断层,场区地表溶蚀现象明显,发育的溶沟溶槽、漏斗、落水洞的展布走向基本与构造方向和优势节理方向相近。而钻孔揭露地下0.5~20 m范围有透水性差的薄层泥岩,该地层下部岩体相对完整,由此可以推断,隔水层以上岩体在水流作用下,沿岩体节理、裂隙溶蚀现象明显,地表岩溶发育,在该隔水层之下,岩溶弱发育。场区虽处Ⅲ级剥夷面上,地表水流除沿岩体裂隙下渗外,绝大部分水流沿地表向地势低洼处径流,而后通过溶斗、落水洞等统一向侵蚀基准面排泄,无大面积积水区域。总体来说,场区以垂向岩溶为主,隔水层表面多发育横向小型溶洞,隔水层上下溶蚀差异较大,钻探过程中未发现厅堂式溶洞,因此场区出现大规模塌陷灾害的可能性很小。研究结果不仅为详勘提供了基础资料,对后期机场的设计和建设均具有重要的指导意义。

Characteristics and Genetic Analysis of Karst Development at an Airport Site in Guizhou

Through the statistical analysis of preliminary investigation data of an airport in Guizhou, the paper has discussed the development features and the distribution law of the karst area and formation mechanism, the site is located in arcuate tectonic zone, is relatively stable, the more development of crumpled and compressive minor faults, the development trend of the melting groove, the melting tank, the funnel and the sinkhole are approximately the same as the tectonic direction and the dominant joint direction. The surface erosion phenomenon is obvious in the field area, while the borehole reveals most of the underground rock mass, and the karst development is weak, the main cause is that the area is less affected by the structure, the rock mass is intact, no large area of water accumulation and less water infiltration, karst weak development, thus the characteristics of the development of surface and subsurface karst are different.The main karst of field area is vertical, no cave has been found during the drilling, therefore, the possibility of large-scale karst collapse disaster is very small, this has certain guiding significance for the construction of the airport at the later stage, and also provides the basic data for detailed exploration.