Method for measuring earth pressure on outer side of shield tunnel

Abstract

The invention relates to a method for measuring earth pressure on the outer side of a shield tunnel. The adopted measurement device comprises an oil bag, a silicon rubber O-shaped sealing ring, a water-swelling rubber sleeve, a cylinder barrel, a piston, a steel wire rope for pulling the piston, a piston installation support component for installation, an electronic control system and an oil supply unit, wherein the oil bag is used to sense soil deformation and transfer earth pressure, is meshed with the cylinder barrel by threads, and presses the silicon rubber O-shaped sealing ring to realize the sealing of hydraulic oil; the lower part of the cylinder barrel is provided with an external thread and an internal thread, the external thread is matched with the internal thread of a hoistinggrouting hole, and the internal thread is connected with the piston installation support component; a convex groove for fixing the piston is arranged at a lower position of the cylinder barrel, the threads at the bottom and the top of the cylinder barrel have opposite directions, and the thread at the bottom of the cylinder barrel has the same direction as the internal thread of the hoisting grouting hole; and the piston is located in the cylinder barrel, and comprises an "upper" part of the piston, a formulation pair wire, a heating rod, a pressure liquid level set temperature transmitter, anoil delivery pipe, an exhaust pipe and a "lower" part of the piston.

Description

technical field [0001] The invention belongs to the technical field of geotechnical engineering testing, and relates to an outer earth pressure measuring device of a shield tunnel. Background technique [0002] The continuous advancement of the country's modernization process requires cities to accommodate a large enough urban population, and the construction and improvement of urban infrastructure ensures the city's high-speed operation and employment capacity. The planning and development of urban rail transit has led to the construction of a large number of subway tunnels. Among them, the shield tunneling method has many advantages such as fast construction speed, high degree of automation, small impact on the environment, and mature industry and technology. It is the preferred method for subway tunnel construction. The shield tunnel is composed of lining segments and joint structures. The lining structure is in direct or indirect contact with the soil through the groutin...

AI Technical Summary

Problems solved by technology

[0006] 2. Influenced by the size of the earth pressure cell

[0008] 3. Affected by the buried state of the earth pressure box

[0009] The earth pressure cell is pre-buried in the prefabricated segment, and along with the production process of the prefabricated segment, it goes through the curing stage together, resulting in uneven pressure distribution on the outer membrane of the earth pressure cell and resulting in measurement errors; During the soil contact process, it cannot be guaranteed that the outer membrane of the earth pressure cell is in good contact with the test soil

[0010] 4. Affected by the sensor itself

[0011] The earth pressure cell is greatly affected by environmental factors. The indoor air humidity is required to be less than 80%, no corrosive gas and ventilation conditions, and it is required to be handled with care when handling. The earth pressure cell that has not been used for a year needs to be re-calibrated; During the test, the zero point of the earth pressure cell will drift with time, so it is not suitable for long-term monitoring of earth pressure

Images