Principles & Techniques of Bioengineering for Civil Engineers

In a broader sense, Bioengineering is the use of life science & engineering to solve human life problems. Here, in this article, we are using the term bioengineering in the context of civil engineering & it basically refers to soil bioengineering. So, Bioengineering can be defined as the use of vegetative measures & small civil engineering structures in order to reduce the shallow seated instability. The living plants or non-living plant materials are used alone or in conjunction with small civil engineering structures for slope stabilization & erosion control. It utilizes locally available resources & is a cost-effective method.

Principles of Bioengineering

Initially, stability is obtained from the small civil engineering structures. The strength of those structures decreases gradually. After the handover point, stability is derived from the vegetative measures. This can be depicted from the graph shown below:

Functions of Bioengineering

Engineering functions performed by vegetation on a slope are as follows:

Catch
Armor
Reinforce
Anchor
Support
Drain

Advantages of Bioengineering

Immediate slope stabilization & erosion control
Utilization of locally available resources (local tools, local manpower, local materials)
It is a cost-effective method
No need for frequent maintenance
It also provides an opportunity for wildlife habitat
It also improves the aesthetic beauty of the site

Commonly Used Techniques of Bioengineering

Fascine: Bundle of live branches laid in shallow trenches
Palisade: Woody cuttings planted across the slope.
Wattling: Fence made out of vegetative materials.
Bamboo Planting: Planting of bamboo for soil conservation
Grass Planting: Planting of grass across the slope
Brush Layering: Layers of woody cuttings planted in line following the contour
RipRap: Stone pitching with vegetation interplanted between them
Retaining Wall: Wall built to resist the pressure of earth filling or backing