一、 主廠房區(qū)域基礎(chǔ)開挖特點(diǎn)：
1、 根據(jù)地質(zhì)資料，主廠房區(qū)域地表下的淤泥層深達(dá)10m，主廠房基礎(chǔ)一般座落在③淤泥質(zhì)粉質(zhì)土層中。本工程土建結(jié)構(gòu)位于軟土地基上，樁基保護(hù)是本工程土建基礎(chǔ)施工的一大重點(diǎn)和難點(diǎn)。
2、 主廠房?jī)?nèi)部基礎(chǔ)埋深相差較大，汽機(jī)基礎(chǔ)比汽機(jī)間框架基礎(chǔ)深3.5m；凝泵坑基礎(chǔ)比汽機(jī)基礎(chǔ)深0.5m；循環(huán)水閥門井及其相鄰的A排基礎(chǔ)底板整體現(xiàn)澆，底標(biāo)高比汽機(jī)基礎(chǔ)深1m、比A排其它基礎(chǔ)深4.5m；A排外進(jìn)排水管比A排其它基礎(chǔ)深2.9m。這些布置特點(diǎn)，大大增加了土建地下部分的施工難度，給樁基保護(hù)提出了更高的要求。
3、保證樁基不發(fā)生位移偏位現(xiàn)象，擬采取必要的支護(hù)措施即水泥攪拌樁支護(hù)方案，在主廠房基坑四周布置多排水泥攪拌樁，形成水泥土擋墻。
4、土方開挖底標(biāo)高已低于地下水位，淤泥質(zhì)土層的透水性很小，降水效果不明顯。 
二、 支護(hù)方案
1、 在主廠房基坑周邊、煙囪基坑周邊、循環(huán)水管溝基坑周邊，布置水泥攪拌樁。
鍋爐房、除氧煤倉(cāng)間、汽機(jī)房（除A排）基坑，布置四排雙頭水泥攪拌
First, the foundation excavation of the main powerhouse features:
1, according to geological data, the main plant area of surface layer of silt under the deep 10m, based on generally located in the main building ③ silty soil. The civil works structures located in soft soil, pile protection is the basis of the civil works construction of a major important and difficult.
2, the main difference between the plant and the basis of depth greater than the steam turbine steam turbine foundation based on inter-frame depth 3.5m; condensate pump steam turbine foundation pit of deep foundation than 0.5m; recycled water wells and the adjacent A valve arrangement of the base as a whole is casting, the bottom elevation than the turbine foundation depth 1m, other than the basic A row of deep 4.5m; A exclusion into the basis of drainage other than the A row of deep 2.9m. The layout features, which greatly increased the difficulty of civil underground construction, pile protection to a higher demand.
3, to ensure that displacement does not occur pile deviation phenomenon, to be taken the necessary support measures that support the program of cement mixing pile, arranged around the pit in the main plant more rows of cement mixing to form a cement retaining wall.
4, the end of earth excavation below the water table elevation has, silty soil permeability is small, the precipitation effect was not obvious.
Second, support programs
1, in the main plant around the foundation, chimney foundation pit, circle pit around the pipe trench, decorated cement mixing pile.
Boiler room, oxygen removal coal bin, the steam room (except row A) excavation, cement-head arrangement of four rows
 

前往下載