Construction method of shield excavation-type air-pushed tunnel through ground fissures

Abstract

The invention discloses a construction method of a shield excavation type air-push through ground fissure concealed excavation tunnel, comprising the steps of: 1. Concrete guide platform construction in the ground fissure concealed excavation tunnel; Pushing the whole machine forward: Push the shield machine forward and make the main shield machine supported on the two guide rails, and then use the propulsion cylinder and the reaction frame of the shield machine to push forward as a whole until the push is in place; During the push process, use the shield segment assembly machine of the shield machine to install multiple shield segments on the concrete guide platform from back to front. The shield segment is the bottom segment and it is located at the rear of the push cylinder. The bottom segments are supported on the reaction frame, and a plurality of bottom segments form a trolley translation channel for the rear supporting trolley of the shield machine to translate forward. The method of the invention has the advantages of simple steps, reasonable design, convenient construction and good application effect, and the construction process of the shield excavation through the ground fissure is simply completed by using the inverted arch backfill structure in the tunnel, and the construction process is safe.

Description

technical field [0001] The invention belongs to the technical field of shield tunnel construction, and in particular relates to a construction method of a shield excavation-type empty-push tunnel through ground fissures. Background technique [0002] Empty thrusting of the shield means that the shield machine moves forward without excavation after the commissioning of the shield machine is completed. When shield tunneling through ground fissures is started and arrived at the construction, brackets made of section steel are usually used to receive and start the shield machine into and out of the hole. The ground fissures tunnel refers to the underground Dig tunnels. Shield excavation tunnels through ground fissures usually adopt the construction method of disassembling the shield machine body and supporting trolleys and moving them separately. The shield machine body and the steel bracket are integrally pushed by jacks to excavate through ground fissures. In the tunnel, the...

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Problems solved by technology

The above-mentioned construction method mainly has the following defects: first, the weight of the section steel bracket and the starting reaction force frame is relatively large, and the hoisting, transportation and disassembly of the components are extremely inconvenient due to the space limitation of the underground excavation tunnel and the influence of vertical and horizontal transportation; 2. The reaction force point of the shield excavating the tunnel through the ground fissure is frequently changed, which seriously affects the transit time; moreover, it is necessary to set up the reaction fulcrum of the jack every 6 meters to 9 meters, and there are many fulcrums and fulcrums. On the one hand, due to the dual constraints of the small radius of the tunnel curve and the narrow space of the ground fissure, the construction is difficult, the safety risk is high, the cycle is long, and the cost is high; thirdly, the shield machine body and the supporting trolley need to be disassembled and moved separately. The efficiency is extremely low, and the construction period for the shield machine body and the supporting trolley to be reassembled after passing through the station separately is longer, and the cost increases, which greatly increases the construction period and economic cost; fourth, there are many unsafe factors, and safety management is difficult , and due to the self-heavy weight of the steel bracket and the starting reaction frame, the space of the ground fissure underground excavation tunnel is small, and it is difficult to hoist, transport and disassemble in the tunnel and the safety risk is great; install the steel bracket in the ground fissure underground excavation tunnel Due to the influence of the small space, the positioning of the steel bracket is difficult, the error is large, and the reinforcement is not firm, which is prone to problems.

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