Construction Earthwork and Excavation Techniques
Geotechnical Testing and Site Preparation
Geotechnical Soil Testing
Soil testing (geotechnical) is performed through test borings to determine foundation pressure and bearing capacity. Samples are taken across the site and summarized in a comprehensive geotechnical report.
Subgrade Preparation and Layout
Subgrade preparation involves several critical steps:
- Clearing the site and removing organic topsoil.
- Excavating to the required depth.
- Grading and compacting the soil to the proper density.
- Replacing soft
Essential Techniques in Underground Construction and Tunneling
Underground Construction Fundamentals
Underground construction refers to the building of structures beneath the Earth’s surface. This can include various types of facilities like tunnels, subways, basements, mines, parking lots, utility networks (e.g., water, sewer, and electrical lines), and even underground buildings or storage facilities.
Key Aspects of Underground Construction
Purpose and Applications
- Transportation: Subways, tunnels for highways, and pedestrian passageways are essential for efficient
Geologic Time Scale, Earth’s Structure, and Rock Properties
The geologic time scale (GTS) is a system of chronological dating that relates geological strata (stratigraphy) to time. It is used by geologists, paleontologists, and other Earth scientists to describe the timing and relationships of events that have occurred during Earth’s history.
The 4.6 billion-year geologic time scale is subdivided into different time periods of varying lengths. All of Earth history is divided into two great expanses of time.
The Precambrian began when Earth first formed 4.6
Read MoreConstruction Materials: Types, Properties, and Uses
Ceramics
NSF rocks are composed of significant-sized mineral particles and indeterminate forms. They are used for building stone.
Igneous Rocks
These include:
- Granite: Composed of quartz, feldspar, and mica. Used in the form of crushed gravel for making concrete.
- Gabbro and Diorite: Used as an ornamental stone and for laying road surfaces.
- Basalt: Slightly resistant to atmospheric effects.
- Liparita and Pumice: Very porous rocks, used for the preparation of lightweight aggregates.
Sedimentary Rocks
- Siliceous
FEM Concepts: Material Nonlinearity, Approximation, and Elements
1. Give the example of material nonlinearity. Material nonlinearity involves the nonlinear behaviour of a material based on a current deformation, deformation history, rate of deformation, temperature, pressure, and so on. Examples of nonlinear material models are large strain (visco) elasto-plasticity and hyperelasticity (rubber and plastic materials).
Approximation Sources in FEM
2. Give two examples of approximation sources in FEM
Shape Functions: Shape functions are used to approximate the variations
Read MoreReinforced Concrete: Properties and Uses
Reinforced Concrete
Reinforced concrete is a composite material formed by combining cement, water, fine aggregate (sand), coarse aggregate (crushed stone or gravel), and air. Admixtures, also known as additives, can be included to modify the properties of the fresh or hardened concrete. The concrete mixture is placed in formwork and then cured to facilitate the hydration reaction, a chemical process that produces a hard, rock-like material.
Aggregates
- Fine Aggregates: Typically natural or manufactured