The main methods of internal disease detection are:

The internal diseases of the tunnel mainly include: insufficient lining thickness, cavities behind the lining, groundwater behind the lining or weakening of the surrounding rock, insufficient concrete strength and non-compactness, etc., these internal diseases are easy to induce cracking, water leakage, spalling and other structural surface diseases, and even cause collapse, water surge and other disasters, seriously endangering the structure and traffic safety. Therefore, the detection of diseases inside the tunnel is essential to grasp the technical status of the structure and ensure the safety of the operation.

In the traditional detection method of tunnel disease, the core drilling method can detect the internal disease of the tunnel, but it is bound to cause secondary damage to the tunnel structure, which may induce sudden disasters, and the detection efficiency is extremely low, which cannot meet the needs of large-scale maintenance inspection. To this end, non-destructive testing instruments such as ground penetrating radar, ultrasonic detector, and rebound tester have been tried to be applied to the detection of diseases inside the tunnel.

Ground penetrating radar and ultrasonic testing technology have been widely used in non-destructive testing of tunnels, and infrared temperature detection technology has also been applied to a certain extent. Among them, ground penetrating radar can be used to detect the thickness of the lining, the cavity behind it, and can judge whether there is a large-scale groundwater body behind the lining; Ultrasonic is mainly used to detect the strength of concrete, whether the lining and the initial support are closely attached.

1. Detection of railway subgrade diseases.

Railway subgrade disease generally refers to the filling pit, cave or slag filling of a certain scale formed by the inconsistency of the top structure of the railway subgrade platform and the inhomogeneity of the original filler, and the long-term rainwater erosion and infiltration, driving vibration, etc. The subgrade disease is relatively hidden, and once it collapses due to the influence of external factors, it will directly threaten the safety of driving, so the investigation of railway disease is very important.

In subgrade investigation, due to the influence of electromagnetic interference, rail interference and driving vibration interference, the application of some geophysical methods is limited, so the geophysical method commonly used for railway disease detection is microgravity measurement.

Due to the certain density difference between the diseased section and the intact section of the roadbed, it provides a premise for microgravity measurement. It is a microgravity anomaly contour map of the karst cave under the embankment on the Bordeaux-Sète railway line in France, the measurement location is located at the railway line Balsac, the object of investigation is the 5m high embankment and the subgrade, and there is a dense section in the middle of the belt (anomaly up to 3 10, which is a lot that has been grouting in the past. In the past, it was not possible to carry out a specialized study due to the sudden collapse.

Two anomalies 2 10 1 6 10 occurred at both ends of the lot, located at the base of the slope and extending under the subgrade. Interpretation of the anomaly and drilling validation confirmed the presence of karst caves in the limestone at a depth of 3 6m below the roadbed.

The railway subgrade is mostly compacted with cultivated soil piles, and if there is a subgrade disease, it will inevitably cause electrical differences. The subgrade is located above the ground (or above the shallow water surface), so whether it is a cave or a slag fill, the apparent resistivity within the scope of the exploration volume can be increased, so that the symmetrical quadrupole profile will have a high-resistance anomaly, and the more serious the subgrade disease, the larger the scale, the more obvious the high-resistance anomaly.

Summary. In the process of cultivation, medicinal plants are affected by the infection of pests or adverse environmental conditions, the normal metabolism is disturbed, and a series of changes and destruction occur from physiological functions to tissue structure, so as to present abnormal lesions in the external morphology, such as wilting, rotting, spots, mold powder, flowers and leaves, etc., collectively referred to as diseases.

The causes of the pathogenesis of medicinal plants include biotic and abiotic factors. Diseases caused by biological factors such as fungi, bacteria, viruses, etc., which invade the plant body, are infectious, called infectious diseases or parasitic diseases, and diseases caused by abiotic factors such as drought, waterlogging, severe cold, nutrient imbalance, etc., which affect or damage physiological functions, are not infectious, and are called non-infectious diseases or physiological diseases. In infectious diseases, the pathogenic parasites are called pathogenic organisms, among which fungi and bacteria are often called pathogenic bacteria.

The infected plant is called the host plant. The occurrence of infectious diseases not only depends on the role of pathogenic organisms, but also is closely related to the physiological state of the host and the external environmental conditions, which is the result of the interaction between pathogenic organisms, host plants and environmental conditions.

What is one of the important bases for diagnosing pests and diseases.

Hello, I'm glad to answer for you, I'm Mr. Yaoyao.

The symptoms are: Symptoms are one of the most important bases for diagnosing pests and diseases.

In the process of cultivation, medicinal plants are affected by the infection of pests or adverse environmental conditions, the normal metabolism is disturbed, and a series of changes and destruction of rotten bushes occur from physiological function to tissue structure, so as to present abnormal lesions in the external morphology, such as wilting, rotting, spots, mildew powder, flowers and leaves, etc., collectively referred to as diseases. The causes of the pathogenesis of medicinal plants include biotic and abiotic factors. Diseases caused by biological factors such as fungi, bacteria, viruses, etc. invading the plant body are infectious, called infectious diseases or parasitic diseases, and diseases caused by abiotic factors such as drought, waterlogging, severe cold, nutrient imbalance, etc., which affect or damage physiological functions, are not infectious, and are called non-infectious diseases such as nuclear diseases or physiological diseases.

In infectious diseases, the pathogenic parasites are called pathogenic organisms, among which fungi and bacteria are often called pathogenic bacteria. Infested hungry oak plants are called host plants. The occurrence of infectious diseases not only depends on the role of pathogenic organisms, but also is closely related to the physiological state of the host and the external environmental conditions, which is the result of the interaction between pathogenic organisms, host plants and environmental conditions.