深基坑明挖法内衬混凝土侧墙裂缝原因分析及对策

Cause Analysis and Countermeasures of Crack in the Concrete Lining Wall for Deep Foundation Pit

混凝土是一种由骨料、水泥、空气和水组成的非均质脆性材料,在温湿度变化、荷载、约束等的条件下,硬化混凝土内部容易形成初始应力,造成在混凝土内出现微裂缝。在荷载或应力作用下,裂缝发展、延伸,并逐渐互相贯通,从而出现较大的肉眼可见的裂缝。混凝土裂缝也是混凝土工程的通病,尤其是钢筋混凝土结构开裂后,严重影响结构的安全和耐久,进而影响整个工程的质量与使用寿命。而混凝土结构不同、设计参数不同、施工工艺工法不同均会产生不同形式的裂缝,根据深基坑明挖内衬混凝土侧墙产生的竖向裂缝,分析设计、施工、原材料等方面的因素,并针对性地提出预防措施,以供借鉴。

Concrete is a kind of heterogeneous brittle material with composition of aggregate, cement stone, air and water, under the changes of temperature and hunfidity, load and constraint conditions, the initial stress will appear during nd concrete hardening, which could result in micro cracks in the concrete. Under the action of load or stress, the crack develops, extends and gradually penetrates through, then the large visible crack will ap- pear. The concrete crack is also a common failing of concrete engineering, especially for the structure of rein- forced concrete, which will seriously affect the safety and durability of the structure, and then affect the whole engineering quality and service life. The causes of cracks in concrete structures include a variety of reasons and forms, as different structures, different design parameters, different construction technology and construction method will produce different forms of cracks. In this paper, according to the vertical cracks in the side wall lin- ing concrete at open cut deep foundation pit, a comprehensive analysis on the design, construction, raw materi- als and other factors has been carried out, and the prevention measures have been put forward, which could be used as references.