The work of a civil engineer begins when a certain need arises (a new dock in a port, the expansion or construction of a road, a dam that gives continuity and stability to the flow of a river...). In this planning stage, civil engineers work in an integrated manner with other professionals and national or local authorities with decision-making power.
Then comes the work of collecting the data necessary to design a solution to said need, data that can be topographic (measurement of the real surface of the land), hydrological (rainfall of a basin, flow of a river, etc.), statistical (capacity of existing roads or streets, population densities), etc.
For this purpose, the designs of the most complex works and systems are done in several stages. The first stage called "pre-feasibility"), is responsible for analyzing the greatest number of possible solutions. It is in this stage in which the competent organizations will decide, for example: the location of a port, the general layout of a highway or will make the decision regarding whether to build a railway to transport minerals or a mineral pipeline. For decision making, the following points of view are considered, among others: difficulty of the work; cost of the work; environmental impact produced by the work. The study of Pre-feasibility involves a multidisciplinary team of technicians, where in addition to civil engineers, electrical engineers, mechanics, geologists, economists, sociologists, and ecologists participate. As a result of this phase, 2 or 3 solutions are chosen to be detailed in the next stage.
In the next stage, called "technical-economic feasibility"), much progress has already been made in the construction details, in the determination of costs, in the construction schedule and in the cash flow necessary for the execution of the work. In this stage, field investigations have a lot of weight to detect specific difficulties related to the geology of the areas in which the intervention will be carried out, and the environmental impacts will be detailed, including both the physical, abiotic and social parts. In general, it is in this phase that the solution is chosen. final, which will be detailed in the final design or executive project stage.
Then comes the real work on the land: conditioning it so that it is capable of supporting the structures that are going to be built on it (sometimes even replacing the land with another with a greater load-bearing capacity if the existing one does not meet the necessary conditions), earthworks (clearings and embankments), construction of the structures (piles, footings, pillars, abutments, beams, retaining walls).
However, all of these steps are rarely carried out smoothly, much less the responsibility of the same engineering team. Thus, it is often the engineers of the corresponding Administration who detect the need that will be solved, while on other occasions the work is included within a political action plan (not always with a clear technical justification).
If the work to be undertaken is large-scale, the Administration does not execute it, but rather its engineers prepare a preliminary project that is put out to public auction. Then it is the engineers of the different construction companies who, based on the technical prescriptions of the preliminary project, develop different alternatives. The alternatives offered by the construction companies may be very different from the preliminary project and from each other, since each company uses the machinery and procedures that are best known to it, and the Administration will choose the cheapest of the options that meet the requirements.
The engineers who carry out the work do not have to be (nor generally are) the ones who designed it. The construction company may also decide to subcontract different jobs to other companies, so there may be different companies for the same work (one carries out the earthworks, another the concrete structures...) each with its corresponding engineering department and its corresponding team of engineers on site.
Very often, due to the unpredictability of the terrain, problems occur on site that require modifications to the project; On other occasions, the Administration may decide to vary some conditions or requirements as the work develops and problems or possibilities are observed that had not been studied or that were not considered important at the time the preliminary project was prepared. It may happen that a new infrastructure requires modifications or the possibility arises that two different works, built by different companies (of course with different teams of engineers) are executed together.
All of this can give an idea of the large number of variables that affect civil engineering work. Large-scale works are rare, and more frequently the civil engineer is limited to supervising the work and making specific decisions on specific problems that do not affect the development or general budget of the work. Thus, works such as the containment of a terrain with usual characteristics, the placement of a prestressed beam or the execution of a pavement, are routine works that do not imply significant changes to the project.
Civil Engineering is a fundamental discipline for the development of society, since it is responsible for the design, construction and maintenance of infrastructures that facilitate daily life, such as roads, bridges, buildings and water systems. Its importance lies in guaranteeing safe, functional and sustainable works that promote economic and social progress, while promoting the responsible use of resources and environmental protection.