Methodology of Highway Engineering Structural Design and Construction

From the 8th century B.C. to the 2nd century B.C., the wisest men of all mankind were born almost at the same time, for example, Confucius, Sakyamuni, Socrates, Plato and Aristotle, who made this period the so called “Axis Age”. Ancient Greek philosophers mainly considered the relationship between human beings and things (the objective world). Philosophy and science were not separated and natural philosophy developed. Ancient Indian philosophers mainly considered the relationship between human beings and god (transcendental world) and transcended the world of man’s experience. Ancient Chinese philosophers considered not only the relationship between human beings, but also that between human beings and nature (the relationship between nature and human beings), emphasizing harmony and a win-win situation. The fusion of Chinese culture (changing the unsuitable part, absorbing the advanced part from the outside and strengthening the adaptive ability) absorbs the advanced culture from outside on the basis of adhering to Chinese culture, and constructs a more advanced culture to serve the people, just like adding an alloy into steel to forge a better steel alloy. For example, every bit of progress in Chinese history can be seen in the course of cultural integration, such as the Qin, Han, Tang and Yuan dynasties, which combined various cultures, especially the promotion of harmony among Confucianism, Buddhism, Taoism and so on, and the contemporary integration of Marxism and Western science and technology has achieved inclusiveness in both Eastern and Western civilizations and ways of thinking, but the Ming and Qing dynasties did not grasp the general trend and they lag behind the pace of the Western Industrial Revolution, that is, reform and opening-up and grasping the general trend will lead to development, while conservative, closed and misjudgment of the era will lead to backwardness. Therefore, the British scholar Joseph Needham’s (1900–1995) question “Although ancient China made many important contributions to the development of human science and technology, why didn’t science and the Industrial Revolution take place in modern China?” can be easily understood, as long as the state adheres to the state policy of “the combination of reform and opening-up, grasping the general situation, centralized planning and overall promotion”, the key is to grasp the general situation and the united front and the Party’s construction, and there will be continuous progress and the problem will be solved.

Academician Pan Jiazheng pointed out in his article Philosophical Thinking in the Construction of Water Conservation (Journal of the China Academy of Water Conservation and Hydropower Science, Volume 1, Issue 1, June 2003): Water conservation engineers have many disciplines to master and cannot spend much energy on philosophical issues. But one’s thoughts and deeds are always dominated by one’s epistemology and world outlook. If there is any deviation in these aspects, although you have a good heart and master modern scientific and technological knowledge, it will often get half the result with twice the effort and even lead to unexpected consequences. In this way, it is helpful for hydraulic engineers to read some philosophical books. But engineers don’t have to read great classics, and sometimes a high-level philosophical essay is not as useful as a proverb. The article vividly summarizes the experience of water conservation projects into eight problems and explains the profound in simple terms, including: (1) the philosophy of looking in the mirror; (2) the philosophy of air travel; (3) the philosophy of taking traditional Chinese medicine; (4) the philosophy of holding eggs; (5) the philosophy of eating arsenic; (6) the philosophy of physical examination; (7) the philosophy of managing children; (8) the philosophy of eating crabs.

Engineering mechanics is based on the determination of material properties and microstructure, but some engineering structures will change in the process of loading, and the mode and rule of that change are unknown. For example: unfavorable structures or composite engineering structures such as flexible bending members, broken surrounding rocks, soft soil foundation, etc.; therefore, the application of engineering mechanics to solve engineering structural problems is conditional. That is to say, comprehensive research should be carried out first. When the engineering structure does not meet the above conditions, engineering measures should be taken to control the stress and the state of deformation of the engineering structure, and then an analysis of the engineering mechanics should be carried out. For example, Karl Terzaghi, the founder of soil mechanics, concluded in his later years that “soil mechanics is not so much science as technology. The most important purpose is to reasonably complete the design and construction of geotechnical engineering, and mathematics and mechanics are just the means”; for another example, Western economic theory cannot analyze the history of Western industrialization, nor the achievements of China’s reform and opening-up, and 90% of the content of economic theory is more difficult for enterprises to apply, just limited to the mathematical tools of many economists, without grounding in theory. Therefore, the comprehensive methods of research and analysis are inseparable. To solve the structural problems of highway engineering, it is necessary to carry out mathematical and mechanical analysis on the basis of comprehensive research, so as to better grasp the fundamental problem of the law of stress and deformation of the engineering structure and provide a guarantee for the correct solution of the structural problems of highway engineering.

Modern engineering problems are becoming more and more complex. It is necessary to start from the engineering concept, grasp the main contradictions of the problem or the main aspects of the contradiction, establish a model reflecting the overall state of the stress, and then use modern mathematical and mechanical tools to analyze the engineering mechanical behavior under specific working conditions in detail, simplify the complex problems, and make sure that the results of the analysis cannot only meet the engineering accuracy requirements, but also reflect the mechanical law of the engineering system.

In the calculation of the stress and deformation of engineering structures, there is an implicit assumption of deformation coordination, while some structures are in the same state of uncertainty or instability as infants or young children, so it is difficult to set specific measures in the methods and software of their calculation. At present, when the results of the calculation of engineering structures are inconsistent with the actual results, in some cases, the parameters of the calculation are often adjusted or the model of calculation is modified so that the calculation results are consistent with the actual results, while the coordinated control of structural deformation is ignored, which may lead to problems of the quality and even of the safety of engineering structures. Therefore, the measures for the control of deformation coordination must be adopted in the design and construction of engineering structures. Only by improving the structural design and construction scheme can the deformation coordination conditions be met, and the results of the calculation of engineering structures can be close to the actual results, so as to ensure the quality and safety of the engineering structures. For example, it is generally accepted in the world that the calculation of soft soil foundation force is more accurate and the calculation error of deformation is larger. The settlement calculation of soft soil foundation mainly reflects the trend. The settlement of soft soil subgrade has to rely on control measures. The pile plate structure (patent of China Railway Siyuan) is used in high-speed railways to control the settlement of soft soil after construction, and lime soil subgrade (patent of Jiangsu Province) is used in high-grade highways to control the settlement of soft soil after construction. After the settlement of the soil subgrade after construction, lower partition + pile transition (patent of Zhejiang Province) is adopted for high-grade highways to control the post-construction settlement of the soft soil slag subgrade.

In the process of construction and use of engineering structures, there are often states of metastable equilibrium (state 2) from a state of stable equilibrium to an unstable equilibrium one. As shown in Fig. 6.1, the pile foundation of structure (a) and structure (b) are all in the foundation pit. Structure (a) shows that the crown beam is connected with the column by a hinged connection, and structure (b) shows that the crown beam is connected with the column by compression only without tension support. When there is external force on this kind of structure, structure (a), the ultimate failure will occur only after the external force reaches the ultimate value, and the whole structure will not change in this process, so it belongs to the problem of extreme point instability; on the contrary, when subjected to external force, the columns in structure (b) in the foundation pit have the deformation trend as shown by the arrow, so the deformation often occurs in the whole structure before the structure reaches the ultimate bearing value, This kind of problem belongs to the problem of branch point instability.

The building up of water conservation is an important aspect of the construction of national economic infrastructures. To master a great deal of modern scientific and technological knowledge, water conservation engineers need to think comprehensively and from a higher level. Based on more than 50 years of experience in water conservation and hydro power construction, the author analyzes and considers several aspects of the build-up of water conservation from the perspective of philosophy. With the academic thoughts of ancient and modern Chinese and foreign sages and the practical examples of daily life, this paper makes a historical, dialectical and materialistic reflection and elaboration on the advantages and disadvantages, success and failure, cost and benefits, certainty and risk, refinement and synthesis of methods, the strength and weakness of materials, the coarseness and fineness of norms, avoidance and advantages and disadvantages, prudence and innovation of the construction of water conservation structures.