Controlled blasting technique for small-clear-distance tunnel construction

Abstract

The invention relates to a controlled blasting technique for small-clear-distance tunnel construction. The invention adopts a technical scheme comprising the following: step 1, determining that the safety standard of blasting vibration is 3 to 5 cm / s according to safety requirements of adjacent tunnels or buildings (structures); step 2, performing excavation shallow-hole multi-cycle micro-differential controlled blasting on a construction tunnel according to three steps, namely, to excavate a first step I in an excavation length of 5 to 10 meters by adopting shallow-hole micro-differential controlled blasting and then to successively excavate a second step II and a third step III in an excavation length of 5 to 10 meters by adopting shallow-hole micro-differential controlled blasting as well; and step 3, repeat the step 2 until all tunnel construction is finished. The technique has the characteristics of effectively protecting the stability of surrounding rock and the safety of adjacent tunnels or buildings (structures) and ensuring construction progress and construction safety.

Description

technical field [0001] The invention belongs to the technical field of geotechnical engineering blasting, and in particular relates to a blasting technology for tunnel construction control with a small clear distance. Background technique [0002] With the acceleration of my country's urbanization process and the large-scale development of transportation infrastructure, many cities have started a new round of construction of subway projects, civil air defense projects and urban light rail projects; at the same time, a large number of single-track tunnels need to build second-track tunnels, or New line tunnels need to be built as parallel double lines. These projects often inevitably need to be constructed near existing buildings (structures), or pass under some important surface buildings (structures). In the construction of these projects, as a main construction method, the selection of blasting parameters and the determination of construction technology of tunnel excavation...

AI Technical Summary

Problems solved by technology

At present, the research on tunnel excavation and blasting technology in China mainly focuses on cutting blasting technology, peripheral hole blasting technology, non-cutting excavation blasting technology and tunneling blasting technology when tunnel passes through surface buildings (Fang Junbo, Cui Tianlin. Shallow-buried subway section Impact of Blasting Vibration on Surface Structures [J] World Tunnel. 2000(5): 28~31), (Zhu Zebing, Zhang Dongming. Control of Blasting Vibration in Daping Tunnel Excavation [J]. Engineering Blasting. 2002, 8(4): 65~70), (Dai Qinrong, Li Liangyun. Controlled Blasting Construction Technology of Yanjin No. 1 Tunnel of Nei-Kunming Railway [J] World Tunnel (Supplement). 2000: 316~322), (Zhou Chunfeng. Shock Absorption Control of Urban Shallow Tunnel Excavation Blasting technology [J]. Engineering Blasting. 2001, 7(1): 57~61). Although these technologies have their advantages, they will cause the construction surface to be crowded and some construction workers have no place to work, which will affect the construction progress; construction The flexibility of the plan is poor. When the surrounding rock conditions and construction conditions change, it is difficult to make timely and appropriate adjustments to the original construction plan; especially it will affect the stability of the surrounding rock and the safety of adjacent tunnels or adjacent buildings (structures). Affect construction safety

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