The design and construction of a large reinforced soil embankment for the East Taupo Arterial Project

摘要

A 20m high reinforced soil embankment supports the East Taupo Arterial as it crosses TH2 gully. Therngully is 20m deep and 40m wide with near vertical walls in ignimbrite soils. A small stream runs alongrnthe base of the gully, which is thought to have been formed by fluvial erosion in recent times. Therndesign comprised a mechanically stabilised earth embankment with steep sloping faces whichrnfacilitate vegetation. The reinforced soil section is 17m high and lies above twin 2.1m diameter culvertrnpipes which convey stream flood flows. This paper describes the design and construction of thernreinforced soil embankment. Limit equilibrium and finite element analysis methods were used tornevaluate the strength and deformations of the embankment, including during strong earthquakes. Thernfill material comprised ignimbrite pumice rich soils. These sandy gravels have unusual propertiesrnincluding being very lightweight but having very high strength. Some of the challenges duringrnconstruction are described including access to the gully floor, benching and detailing of the facingrnunits.