Soft Clay Behaviour




Preface

As a civil engineering material, soil is as important as steel or concrete. The unique

feature of this material is that it largely comes engineered by nature, unlike other

materials which have to be manufactured or processed to specific requirements

with the product quality ensured. So geotechnical engineers concentrate on the

cardinal task of characterizing the properties of this natural large volume material,

before integrating the results with analysis to design contemplated structures to

meet the strict performance requirements.

This book is primarily concerned with the analysis and assessment of the behaviour

of soft clay in compression and shearing, both in their undisturbed and

strengthened states. Soft clay deposits are widespread and cover many coastal

regions of the world, such as in Japan, Eastern Canada, Norway, Sweden and other

Scandinavian countries, India, and the South East Asian countries. Another feature

of these coastal regions is that certain shore areas are lowlands, quite often due

to subsidence on account of excessive withdrawal of ground water. The Central

Plain (Chao Phraya) of Thailand and Saga Bay in Southern Japan are some

examples

of lowland areas. All these are inhabited zones, having undergone extensive

urbanization and industrialization. Further extensive developmental activities

are apace in many lowland areas to promote human activities, such as agriculture,

industry, housing and such other infrastructure facilities.

Generally, soft clays exhibit low strength and high compressibility. Many are

sensitive, in the sense that their strength is reduced by mechanical disturbance.

Foundation failure is likely in structures erected in soft clays. Surface loading beyond

yield stress levels due to embankments and shallow foundations inevitably results

in large settlements. It is primarily because these soils respond in a spectacular

manner to stress changes, that the geotechnical engineer

has an obligation to examine to what

extent soft clay behaviour can be analyzed within the framework

of classical developments in soil mechanics.


Download
*