What are the steps of geotechnical investigation?

What are the steps of geotechnical investigation? Geotechnical engineering investigation is mainly carried out in the field. In order to carry out field work in a planned and purposeful way and avoid shutdown and rework, it is necessary to make full preparations before departure, which is an important premise and content of geotechnical engineering investigation. At present, with the expansion of engineering business, some geotechnical investigation projects in new fields that have no research on the geological conditions of construction sites and no architectural experience have increased, and the complexity of the projects has increased, so has the workload that needs to be prepared in advance, which has accounted for a considerable share of its total workload. Whether the preparatory work is sufficient or not will directly affect the quality and progress of geotechnical engineering investigation, and then affect the quality of construction projects. How to do the preparatory work well and how to ensure that the preparatory work is both sufficient and concrete need our great attention.

See and seriously think about the problem.

Second, raising awareness of the importance of the preparatory work is the key to doing a good job in the preparatory work.

Before a survey team engages in a survey project, it is necessary to make good preparations, which is related to many factors, such as the quality of personnel, equipment and economic strength of this team. However, I believe that in practical work, whether the preparatory work can be made concrete and sufficient to avoid negligence and omission depends on the understanding of the importance of the preparatory work. Defining the importance of preparatory work is to make the on-site investigation work planned and purposeful, avoid shutdown and rework, and is the premise and guarantee to ensure the quality of engineering investigation. Unprepared work is very blind, which easily leads to the waste of project costs.

Third, the content of the preparatory work

Geotechnical engineering investigation can be divided into site selection investigation, preliminary investigation and detailed investigation according to different investigation stages. The contents of its preparation work are determined according to the investigation tasks in different investigation stages, and the contents of its preparation work are different in different investigation stages, so it can be carried out from coarse to fine according to different investigation stages. Generally speaking, there are three aspects to be done, the first is to collect data, the second is to arrange drilling holes, and the third is to conduct on-site reconnaissance and positioning.

(1) The work of collecting data is very important and cannot be ignored. A survey team surveyed a project in a community in Shenzhen. The local area is dominated by river alluvial landform, and there are many artificial pits and ponds. After years of landfill, they have become flat. The survey unit did not seriously collect the original local topography and landforms, nor did it visit nearby residents. It only infers the natural foundation from the drilling results. The actual situation is quite different from the survey report during construction and excavation. All the holes in the original building were arranged on the pit and pond.

The main data to be collected are shown in the following table:

(2) According to the importance of the building and the complexity of the site, determine the location, spacing and depth of drilling holes, sampling and in-situ testing parts of technical holes, etc. Will be arranged. See the table below for drilling layout requirements:

The drilling depth should be determined according to the compression layer of the foundation, and the control hole should be deeper than the compression layer to know whether there is a weak substratum. The exploration hole can be shallower than the compressed layer, and the soil layer can be distinguished.

The foundation width b of small and medium-sized projects is less than B.