Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 2414 An introduction to pipe jacking and microtunnelling 4 DESIGN AND CONSTRUCTION METHODS WORKING SHAFTS A range of working shaft construction methods can be used for pipe jacking operations, including: • Segmental lining • Pre-cast or cast insitu caissons • Sheet piling or secant piling • Shallow trench sheeted or timber supported excavation • Battered excavation • Ground anchorages In certain instances, ground treatment or groundwater management methods may be required to enable the construction of the shaft to proceed. These include: • Well pointing and deep wells • Compressed air • Suspension grouts • Chemical stabilisation • Ground freezing The following tables provide a guide to the most common practice for selecting shafts, but are not exhaustive.