Details

Autor(en) / Beteiligte

• Blom, Cornelis Bernhard Marco (Kees)

Titel

Design philosophy of concrete linings for tunnels in soft soils

Ort / Verlag

ProQuest Dissertations & Theses

Erscheinungsjahr

2002

Link zum Volltext

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• Risk identification for tunnels is strongly connected to the understand of the structural behaviour of the tunnel. The assembly of the concrete segmented lining of shield driven tunnels in soft soils and a high water table is pointed to be very important for damages. This dissertation starts with an inventory of the current practice of tunnelling to determine the problems. New analytical engineering models are derived for better understanding of the structural behaviour. An extension is made to current analytical models by implementing explicit longitudinal joint behaviour, lateral ring interaction and soil supports, Applicable load models for soils are described. A new load model is described that incorporates the temporarily load of grout during the assembly of the lining, the so-called uplift loading case. Full non-linear calculations are carried out to analyse the lining behaviour in various conditions. Comparison is made with full-scale tunnel test measurement results and field measurements at two tunnel projects. Special attention is given to results from measurements related to the assembly stage of the lining. The practice is observed to identify mechanisms that cause damage to the lining. This damage is of influence on refurbishment (costs), maintenance and durability. Over thirty mechanisms are identified. Some of the mechanisms are explicitly analysed and it is illustrated that they are the cause of many observed damage patterns. The understanding of the mechanisms should result in alternative design choices. The total study of the lining behaviour is implemented in a design philosophy. Key issue is the involvement of the structural analysis of the assembly of the lining to mitigate risks during the assembly. Furthermore attention is given to plasticity in soils due the assembly process. In a bright discussion one is attended to the strong influence of non-linear behaviour of soils, caused by grouting, that results in settlements.