What are the methods of engineering geological mapping? What are their characteristics?

Engineering geological surveying and mapping is an essential work in the early stage of engineering construction, and its methods include:

1. Geological survey method:

-Field investigation: including field observation, sampling, geological survey, etc. Geological information is obtained through field observation and sampling of geological phenomena, geotechnical structures and groundwater.

-Drilling investigation: drilling underground rocks and soil with drilling equipment to obtain bedding, properties and hydrogeological information of underground rocks and soil.

Geophysical exploration: including seismic exploration, electromagnetic exploration and gravity exploration. Through the observation and analysis of geophysical phenomena, we can obtain the information of underground geotechnical structure and properties.

-Remote sensing technology: Through aerial remote sensing and satellite remote sensing, a wide range of geographical information can be obtained, such as the surface topography and the distribution of ground objects.

2. Surveying and mapping methods:

-Precise leveling: carry out elevation measurement with a level to obtain the elevation information of the terrain.

-Establishment of survey network: Establish horizontal, vertical and control survey networks for subsequent measurement and positioning.

-Angle measurement: use theodolite, total station and other tools to carry out angle measurement to determine the position and orientation of ground objects.

-regional mapping: using aerial photogrammetry, satellite image measurement and other means to obtain large-scale geographic information and make maps.

These methods have different characteristics:

-Geological survey can obtain important information, such as geological structure, geotechnical properties, groundwater conditions, etc. It is helpful to evaluate geological risks and choose suitable engineering schemes.

-Surveying and mapping methods can provide geospatial data, which is helpful to establish an accurate geographic coordinate system and survey network for engineering design and positioning.

Comprehensive use of geological survey and surveying and mapping methods can fully understand the geological environment and geographical characteristics of the project construction area, provide accurate basic data for project design, construction and management, and ensure the safety, reliability and effect of the project.