水泥土搅拌桩(深层搅拌桩)因施工简便、成桩块、价格低、不需井点降水、施工无噪声等优点,目前在上海地区被广泛用于地基加固及基坑围护中。作为围护结构,水泥土搅拌桩或单独或与钻孔灌注桩联合使用。在实际工程中,我们常遇到两种情况:坑底地基为承重水泥土搅拌桩加固的复合地基(见图1);围护搅拌桩前用水泥搅拌桩或注浆等加固土体,以增加墙前被动土压力(见图2)。 Cement-soil mixing piles (deep mixing piles) are widely used in foundation reinforcement and foundation pit enclosures in Shanghai because of their advantages such as simple construction, pile formation, low price, no need for well point precipitation, and no noise during construction. As an envelope structure, cement-soil mixing piles are used either alone or in combination with cast-in-place piles. In the actual project, we often encounter two situations: the foundation of the pit is a composite foundation reinforced with cement-soil mixing piles (see Figure 1); the soil is reinforced with cement mixing piles or grouting in front of the mixing piles. Increase the passive earth pressure in front of the wall (see Figure 2).