交底内容：
1. 对实际开挖深度≤3.0m的基坑，采用自然方坡的方法，放坡系数为1：0.5～1：1，主要是针对土质好地段，坡面抹5.0cm厚C15混凝土，防止雨水冲刷。在K6+950～K8+075里程范围，路基虽然已采用软基处理，但淤泥层厚，桩身强度较差，靠外侧通车道一侧采用拉森钢板桩支护，桩长度不小于9.0m，路堤面用水泥砂浆抹面硬化坡面。
2. 对实际开挖深度≤5.0m的基坑，针对较好土层，上面1.2m采用1：1放坡，坡面喷射C15混凝土硬化层，下面采用拉森钢板桩疏桩支护（间隔施插）；若遇到相对较差土层，采用密排拉森钢板桩支护。钢板桩顶设一道支撑，支撑选用32号双翼工字钢。在K8+075～K8+375、K8+460～K8+850、K9+075～K9+209及K9+600～K9+700里程范围，主要为开挖段，开挖深度为4.0～4.5m，从现场开挖的土质分析来看，为硬塑状粘性土，可采取以上支护形式。
3. 对实际开挖深度＞5.0m的基坑，采用密排钢板桩支护，桩顶以下0.5m设一道支撑，支撑选用32号双翼工字钢，水平间距不大于4.0m。
4. 施工过程中要加强对基坑的监测，每隔20.0m设一个沉降和位移观测点，发现有异常情况时及时采取应急处理措施，如采取回填反压土或坑顶卸土的方法。
基坑降水采用井点降水，保证水位在坑底以下0.5m；施工过程要
Cards on the table contents:
1. On the actual excavation depth ≤ 3.0m of the pit, using the methods of natural side slope, up slope coefficient was 1:0.5 ~ 1:1, mainly for soil good location, slope wipe 5.0cm thick C15 concrete, to prevent rain erosion. In the K6 +950 ~ K8 +075 mileage range, although the use of soft subgrade treatment, but the silt thickness, shaft strength less, by using the lateral side of the opening of Tao Larsen Steel Sheet Pile, pile length is not less than 9.0m, embankment surface finishing with cement mortar hardening slope.
2. On the actual excavation depth ≤ 5.0m of the pit, for the good soil, 1.2m above the 1:1 cut slope, slope jet C15 concrete hardening, the following sparse pile with Larsen sheet pile support (interval Shi interpolation); If they are in relatively poor soil, using closely spaced steel sheet pile retaining Larsen. Set up a steel sheet pile head support wings 32, I-beam support used. In K8 +075 ~ K8 +375, K8 +460 ~ K8 +850, K9 +075 ~ K9 +209 K9 +600 ~ K9 +700 and mileage range, mainly excavation section, excavation depth of 4.0 ~ 4.5m, Excavation of soil from the site of view, the hard plastic clay, may take the form of more support.
3. On the actual excavation depth> 5.0m of the pit, using closely spaced steel sheet piles, pile top the following set up a 0.5m support wings 32, I-beam support used, the horizontal spacing of not more than 4.0m.
4. The construction process to strengthen the monitoring of the pit, every 20.0m set up a settlement and displacement of observation points, found that there is abnormality in a timely manner to take contingency measures, such as taking anti-compacted soil Huo pit backfill the top method of dumping soil.
Foundation pit with well point dewatering, the water level in the pit bottom to ensure the following 0.5m; the construction process to