The current practice in New Zealand for seismic design of shallow foundations is to ensure the LRFD inequality is satisfied, meaning not all of the available bearing strength is mobilised. However, the occurrence of bearing failure may be acceptable, provided the resulting permanent displacements are also…
The soil site spectra for site classes D and E in the current NZ design code impose a significant increase in the displacement demands, between 50 and 300% for a structure with a period of 1.0s or longer, compared with a rock site (class A/B)…
Ground engineers routinely use simple relationships – rules of thumb – to obtain soil parameters and to design ground works. Some of these have a sound theoretical basis and can be applied generally while some are purely empirical and so should be applied only within…
In most design codes, soils are classified as either sand or clay, and appropriate design equations are used to represent their behaviour. For example, the behaviour of sandy soils is expressed in terms of the soil’s relative density, whereas consistency limits are often used for clays. However, sand-clay…
The soil site spectra for site classes D and E in the current NZ design code impose a significant increase in the displacement demands, between 50 and 300% for a structure with a period of 1.0s or longer, compared with a rock site (class A/B)…
During both March and July, 2007 the Far North district of the North Island in New Zealand was hit by a series of severe storm events, which caused over 60 large slope failures along the roading network. Faced with the challenge of remediating such a large number…
This paper describes a case study in Fiji involving the use of pre-loading to accelerate primary consolidation settlement prior to constructing buildings over soft Holocene materials. The pre-loading involved placing a surcharge exceeding the weight of the future structures. Careful monitoring took place to ensure…
This contribution addresses the seat length required to avoid unseating of bridge girders under strong earthquakes. In the investigation simulated ground motions according to the Japanese design spectrum for soft soil site are applied. The analysis of two adjacent bridge structures is performed using a combined finite…
A simplified method of assessing soil structure interaction (SSI) using a single degree of freedom representation of the structure is presented. The simplified method uses recommendations from the SEI/ASCE code and implements the response spectra of NZS 1170.5. Three typical structures are analysed, and it…
The sliding block model proposed by Newmark (1965) is an accepted methodology for assessing the accumulated displacement of a soil slope during an earthquake. For slopes restrained by elastic structural elements, such as geotextile reinforcement or ground anchors, the assumptions behind the Newmark block model may…