| Safety about retaining of deep foundation excavations is always regarded by civil engineering circles. There are many facts effecting instability of Deep Foundation Excavations. Besides the construction technique and administrant level , the unperfect design theory,no complete technique specification about in-situ inspection and no timely prediction and emergent means according to in-situ inspection information are important reasons. The researchful theme of this dissertation is inspection and prediction technique about retaining of deep foundation excavations,the central content is listed as follows.(1) Because of many uncertain facts , it is necessary to inspecting and predicting through the full program of deep foundation excavations . The concept,character,type and design theory of inspection and prediction technique about retaining of deep foundation excavations is stated. (2) The geologic,bearing,material and construction status are complex . the safety of foundation project is affected by It is difficult of predicting actual status by theory analysis. The theory prediction can not reflect the variety fully and truly. So it is necessary to planning and carrying out inspection scheme. This chapter studys the sort,selection,allocation and means of inspection about retaining of deep foundation excavations. The conclusion is that this technique is a system project, it's effect have direct relation with the means and allocation. According to the principle of essentiality,reliability,hiberarchy,key-part,economical,we confirm planning and carrying out inspection scheme.(3) Because the conditions of deep foundation excavations is complex and the cost of construction should be economical , According to principle of measure precision, the apparatus should be simple and applied. This chapter introduces using method and cautionary measures. The emphases is the type,principle,structure,installation and measure of slope indicator. The conclusions are listed as follows.a.Except the theodolite and water level,the other apparatus need be intered concrete or soil. Because of contacting water, the waterproof of apparatus and it's transmission line is most important.b.For the reasons of complexity of the conditions of deep foundation excavations,the measure pots are easy to be destroyed. The measure datum are discontiguous,and it brings big losing for data analysis. So the measure pots must be hard and marked, and demand construction contractors do not destroy them. c.The apparatus most are sensors. Though the manufacturer have demarcate precision for them,the original value is no zero. So the sensors are adjusted their original value before and after installation.d.The signal transmission is depend on transmission line. Because of complex conditions , the transmission line are easy to be destroyed. So the apparatus should be protected carefully and often checked. The cautionary measures should be summarized, and it can ensure precision of the apparatus and veracity of data.(4) This technique's keys are the work of data analysis and evaluating,next predict danger,plan corresponding measure. The inspection without in-depth analysis and evaluating is equal to external description for construction course, can not guide construction and actualize information construction. This chapter study the means of inspection data's analysis and evaluating with project sample. In this process,we should analyse and evaluat it synthetically according as actual data,theory analysis and experience of engineer. It can deal with complex work, and carry out information construction.(5) The traditional design object of deep deep foundation excavations is the final status of excavations according as the structure's bearing strength and whole stabilization. But the process of deep foundation excavations often brings the strain of structure and soil and unexpectable status. So the safety of excavations and environment can not be assured by traditional design. The deformation of structure is the intuitionistic ref... |
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