Abstract Within a major tunnelling-infrastructure project in Southern Germany, the mineral anhydrite of the rock “Grabfeld Formation” (formerly “Gipskeuper”) proved to be challenging with respect to the prohibition of the use of water. Due to its bulking potential (swelling) when anhydrite interacts with water (gypsum) the use of water was prohibited during the complete process of tunnelling works. This led to significant dust production while excavating. Dust poses risk to the human respiratory system and, in order to fulfil health and safety standards and provide a safe work environment, needs to be controlled. Within this task it was monitored, whether certain geotechnical parameters of a rock influence quality and quantity of dust. Additional to tests at the construction site, a laboratory program was designed. Geotechnical tests were conducted with rock material from tunnel drives in the Grabfeld Formation. An usual LCPC device was used as dust generator. A correlation between the water content and the quality and quantity of dust can be shown. However, the point load index is(50) as an indicator of rock strength, showing a correlation with the water content, did not correlate with the quality and quantity of dust.

中文翻译：

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土工参数对隧道工程含硫酸盐粘土粉砂岩粉尘潜势的影响

摘要 在德国南部的一个大型隧道基础设施项目中，“Grabfeld 地层”（前身为“Gipskeuper”）岩石的矿物硬石膏被证明在禁止用水方面具有挑战性。由于硬石膏与水（石膏）相互作用时具有膨胀潜力（膨胀），因此在隧道工程的整个过程中禁止使用水。这导致在挖掘过程中产生大量粉尘。灰尘对人体呼吸系统构成风险，为了满足健康和安全标准并提供安全的工作环境，需要对其进行控制。在这项任务中，监测岩石的某些岩土工程参数是否影响灰尘的质量和数量。除了在施工现场进行测试外，还设计了一个实验室程序。使用来自 Grabfeld 地层隧道驱动器的岩石材料进行了岩土工程测试。通常的 LCPC 设备用作粉尘发生器。可以显示含水量与灰尘质量和数量之间的相关性。然而，点载荷指数是（50）作为岩石强度的指标，与含水量相关，与粉尘的质量和数量无关。