The development of structural physics can be divided into three stages.
The first stage (1920～1930): In order to understand the phenomenon of structural deformation, mud, petrolatum, beeswax, etc. were used for morphological simulation experiments. People know very little about mechanics and rock mechanics properties.
The second stage (1930～1940): There are two important characteristics: ① Mechanics and structural geologists cooperate to apply mathematics and mechanical theories to the study of structural deformation. ②The establishment of the high temperature and high pressure laboratory enables the simulation of the deformation conditions in the deep underground.
The third stage (starting in 1940): the combination of structural physics research and natural structural deformation. Apply the mechanical theory of rock properties under different stress conditions, equivalent to the results of rock mechanics experiments and structural petrology under 10 kilometers of underground temperature and pressure, and the results of field geological work combined with the two to explain the geological structure. Structural physics became an independent discipline in 1940.
The geomechanics founded by Li Siguang in the 1920s is an early pioneering work in structural physics. The lithosphere is an anisotropic geological body, and its deformation behavior strictly depends on the temperature and pressure combination of the environment; on the other hand, the tectonic deformation varies greatly in time and space scales, such as from a few seconds of earthquake to above It is difficult to understand the nature of structural deformation due to the evolution of orogenic belts over 100 million years.
Tectonic physics is based on the observation and research of the tectonic deformation of the crust or the lithosphere, applying the results of experimental petrology, material science and rock mechanics, through the observation of natural structural deformation phenomena, high temperature and High-pressure experiments, physical simulations and numerical simulations using similar materials, in order to understand the true process of rock deformation from the mineral lattice to the continental and oceanic lithosphere, and reveal that the rock under different media, temperature, and pressure conditions The difference in deformation and the law of deformation, etc.
The research content of structural physics includes:
①Types of structural deformation bodies, deformation characteristics, deformation mechanisms and deformation conditions;
②Mutual combination, genetic relationship and distribution of structural deformation bodies in space and time;
③Influencing deformation mechanisms and deformation characteristics in the crust and upper mantle (see the earth) Various factors;
④The stress field characteristics and driving force of deformation.
The structural deformation studied by structural physics can differ by more than ten orders of magnitude (a few seconds to hundreds of millions of years) on the time scale. The time is short, such as an earthquake, and the time is long. Like the evolution of large-scale orogenic belts; it can range from 10-8 cm to 108 cm in space. Due to the different deformation levels of the crust and upper mantle, the deformation physical and chemical environment is very different. The pressure ranges from 1×105 Pa to 2×109 Pa, and the temperature ranges from 20 to 2000 ℃. As a result, people's understanding of structural deformation is sporadic in space and incomplete in time. Structural physics provides a scientific method to deduce unknown structural deformation from known structural deformation.
①Using a variety of detection methods to observe, synthesize and test various structural deformation phenomena in nature;
②Using high-temperature and high-pressure experimental methods to study rock deformation behavior and deformation under different environmental conditions Mechanism, composition change and deformation state equation. These environmental conditions include physical environment such as temperature, pressure, pore pressure, solution composition, mineral equivalent physical and chemical environment, structural conditions such as structural surfaces, defects, and mechanical conditions such as stress state, strain rate, and deformation history;
③Using similar materials to conduct physical simulations of structural deformations under different geotectonic backgrounds;
④Numerical simulations of various structural deformations. In this way, through the synthesis of various observed phenomena, a deformation theory model is proposed; starting from the hypothetical model, digital simulation or physical simulation methods are used to infer the unknown area, and then back to the observation to test, more realistically Reflect the deformation characteristics of the lithosphere.
Different from traditional structural geology, which focuses on the geometry and kinematics of structural deformation, structural physics studies the deformation mechanism, conditions, and formation of the deformed body The stress state of the physics focuses on the dynamics and physics of structural deformation. Traditional engineering rock mechanics focuses on studying the essential relationship and failure process of rock or rock mass deformation under normal temperature and pressure, while structural physics pays attention to studying the deformation and failure characteristics of rock and rock mass under different temperature, pressure and hydrochemical conditions. In addition, structural physics links the macro-deformation properties and micro-deformation mechanisms of rocks through experimental research and microscopic observations, which promotes the development of structural petrology, and closely links it with structural geology, making big, small, and slightly different The study of structural deformation of different scales is integrated.
Tectonic physics has increasingly demonstrated its important theoretical significance in the comprehensive research and exploratory research of global and regional structural deformation, in the genesis and prediction of earthquakes, reservoir earthquake prediction, mine rockburst prediction, It also has important practical significance in the research and production of oil and gas exploration and development, mineralization structure research, engineering stability, nuclear waste storage, and geothermal resource utilization.