Deep foundation pit open cutting construction method

Abstract

The invention discloses a deep foundation pit open cutting construction method, which is characterized in that vertically knocking steel plate piles are arranged on the inner side of four concrete annular beams under a foundation pit soil outlet, the upper end of the steel plate piles is positioned at the same level as the upper surface of the first concrete annular beam, the lower end of the steel plate piles exceeds the lower surface of the lowest concrete annular beam by a certain length, first step soil digging is started, the first concrete annular beam is constructed, at the time, the steel plate piles are knocked in, then, the second step soil digging is started, and a soil table at a preserved soil outlet is maintained without being dug and is used for locating a digging machine. During the construction of a section of second concrete annular beam under the soil outlet soil table, firstly, earthwork is pulled and dug under the first annular beam, the position of a section of annular beam at the soil outlet is dug, the second concrete annular beam is completed through casting, the construction of each following concrete annular beam can be completely by parity of reasoning, and the soil is dug to the tank bottom. The method of the invention does not need to dig and fill back the earthwork platform at the soil outlet for many times, the construction program is simplified, the earthwork work load is reduced, and the construction cost is saved.

Description

technical field [0001] The invention belongs to the technical field of underground engineering construction, and relates to a deep foundation pit open excavation construction method, which is a deep foundation pit construction method in which steel sheet piles retain soil in a concrete ring beam and excavate earthwork to pour concrete ring beams below the excavation opening of the foundation pit . Background technique [0002] With the continuous development of municipal construction and infrastructure construction, the development and utilization of large-scale underground spaces are constantly increasing. Underground engineering plays an important role in engineering construction, and its technology is relatively complicated. It requires safety, reliability and economy in construction. Deep foundation pit construction in underground engineering is an important part of completing underground engineering construction. Deep foundation pit generally refers to the excavation ...

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Problems solved by technology

[0006] The above-mentioned construction method has the following defects: since the soil in the deep foundation pit needs to be poured out of the groove step by step by multiple excavators, and the top excavator must be located on the soil platform of the excavation opening of the foundation pit, it is necessary to keep the excavation. At the same time, it is necessary to pour a section of concrete ring beam under the soil platform to form a closed ring support structure. In this way, it is necessary to repeatedly excavate and backfill the earthwork at the excavation opening, which will cause waste of machinery and manpower and delay the construction period.

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