The Harwich Formation in central London is a collection of relatively thin, marginal to fully marine sediments comprising the Swanscombe, Oldhaven and Blackheath members. Their presence in London has long been of concern to engineers and particularly tunnellers, because they vary so much: from glauconitic silt to sandy gravels, and all members may be cemented in places. Where they occur, and which lithologies are present has been historically difficult to predict or map.

This paper, which is based on Chris King’s and the authors’ work and teaching, looks at the distribution, lithologies and properties of the Harwich Formation members in the London area, and introduces the engineering risks they may represent.

伦敦中部的哈里奇组是一个相对较薄的边缘，到海底沉积物的边缘，这些沉积物包括斯旺斯科姆，奥尔德黑文和布莱克希思成员。长期以来，它们在伦敦的存在一直引起工程师特别是隧道工人的关注，因为它们的差异很大：从青釉质粉砂土到砂砾石，所有成员都可能被粘在某个地方。历史上很难预测或绘制出它们的位置以及存在的岩性。

本文基于克里斯·金（Chris King）和作者的工作和教学，研究了伦敦地区哈里奇组成员的分布，岩性和性质，并介绍了它们可能代表的工程风险。