Gypsum-related sinkhole remediation Magdalen Road, Ripon, Yorkshire UK

英国约克郡里彭 Magdalen 路与石膏相关的天坑修复

• 批准号: NE/P020933/1
• 负责人: Oliver Kuras
• 金额: $ 6.64万
• 依托单位: British Geological Survey
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FP020933%2F1
• 关键词: Gypsum; related; sinkhole; remediation; Magdalen

Unfortunately the recent sinkhole in Magdalen Road, Ripon (10 November 2016) was not the first to affect Ripon. The impact of the dissolution of the buried gypsum is notorious (Cooper 1998) in this area. It results from the generation of drop-out sinkholes with a potential to cause significant damage to buildings and infrastructure. The geology beneath Ripon comprises Permian marls, dolomitised limestones and gypsum, capped by approximately 10 m of glacial deposits. Dissolution of the soluble gypsum at depth results in buried voids that propagate to the surface as sinkholes. The detail of how the sinkholes develop is not fully understood (size and position of the dissolutional openings that develop in the gypsum). This is because the cavities are inaccessible and water filled. Once a sinkhole develops the ground adjacent to it is unstable; access to the sinkhole is not possible, and any intrusive investigation (such as boreholes) have the potential to further destabilise the ground. Consequently, the sinkholes are usually remediated to make them safe as soon as possible. Historically, microgravity geophysical techniques have been demonstrated to be the preferred technique for detecting buried cavities and disturbed ground associated with the dissolution. Here we propose to use a range of geophysical techniques to monitor the remediation (infilling of the cavity) and record changes to the condition of the ground throughout the depth of the sinkhole in order to learn more about its geometry and depth and hence the likely formational processes. In parallel we propose to use the borehole records held by the National Geoscience Data Centre to generate a 3d geological of the Ripon area and attribute this with the geometry of the sinkhole and the associated zone of disturbance in order to further the understanding of the geological context of the sinkhole, i.e. in relation to the distribution of the host sediments and the groundwater table.As well as contributing to the process understanding, this approach will (i) allow the comparison of a range of geophysical techniques (micro-gravity, electrical resistivity and seismic) to assess their viability for void detection and remediation monitoring, which will help inform guidance for any subsequent events and (ii) it will feed back to inform investigation requirements for proposals for any future developments.

不幸的是，里彭抹大拉路最近的天坑（2016年11月10日）并不是第一次影响里彭。埋藏的石膏溶解的影响在该地区是众所周知的（库珀1998）。这是由于产生了脱落的天坑，有可能对建筑物和基础设施造成重大损害。里彭下方的地质包括二叠纪泥灰岩、白云石化石灰岩和石膏，顶部覆盖着约10 m的冰川沉积物。溶解的可溶性石膏在深度的结果在传播到表面的天坑埋的空隙。天坑如何发展的细节还没有完全了解（石膏中溶解开口的大小和位置）。这是因为洞穴是无法接近的，充满了水。一旦天坑形成，邻近的地面就不稳定;不可能进入天坑，任何侵入性调查（如钻孔）都有可能进一步破坏地面的稳定。因此，通常会对天坑进行补救，以尽快使其安全。从历史上看，微重力地球物理技术已被证明是探测与溶解有关的埋藏洞穴和扰动地面的首选技术。在这里，我们建议使用一系列的地球物理技术来监测补救（填充的空腔），并记录变化的地面条件的整个深度的天坑，以了解更多关于其几何形状和深度，因此可能的形成过程。与此同时，我们建议使用国家地球科学数据中心保存的钻孔记录来生成里彭地区的3D地质图，并将其与天坑的几何形状和相关的扰动区进行归因，以便进一步了解地质情况天坑的背景，即与宿主沉积物和地下水位的分布有关。除了有助于理解过程外，这种方法将（i）允许比较一系列地球物理技术（微重力、电阻率和地震），以评估其用于空洞探测和补救监测的可行性，这将有助于为任何后续事件提供指导，以及（ii）它将反馈，以通知对任何未来发展的建议的调查要求。