"Вестник МГСУ"

At present, while evaluating bored piles load capacity in clay soils by CPT data, the depth of active area below the end face plane, within which the averaging of CPT values takes place, is taken as different in different Codes. Thus, for instance, in native Codes and Recommendations the depth of active area is taken from 2 to 4 pile diameters. In foreign Codes such as Belorussian, the depth of active area is taken up to 4 pile diameters and in European Codes - within 0,8-4 pile diameters. In order to specify the regularities of active area forming at different stages of loading, in-situ experimental investigations of large scale models have been carried out. At the test site, two small scale bored piles with the diameter of 130 mm were penetrated into the soil to the depth of 1100 m. The investigations were carried out in two stages: the first - pile static test with measuring of soil vertical displacements with the help of deep marks; the second - digging out soil around the pile and soil sampling at different depths. According to the results of the investigations carried out, the depth of the active area while reaching the limit state was determined to be about two pile diameters. With significant pile settlements (more than 0,58 d), the dimensions of this area do not exceed three pile diameters below the end face plane, and two diameters to the side from the pile axis. Within the lateral surface the significant variation of soil physical characteristics appears to be at the distance not less than 0,4 pile diameter from the lateral surface. Due to investigations’ results, it can be noted that in case of bored pile load less than the limit one, the depth of the active area is about two pile diameters. When the pile reaches its limit state, that provokes significant settlements, zone of compaction does not exceed three diameters to the depth and two diameters to the side from the pile axis.

Subject: the article describes the structure, technologies of construction, gardening and exploitation of the Holy Trinity Seraphimo-Diveevsky Monastery - the ancient linear fortification consisting of a ditch and an earth embankment that is located directly above the ditch. Research objectives: ensure the stability of slopes, create a technique for gardening of steep slopes in difficult microclimatic conditions, ensure drainage of water. Materials and methods: the computational techniques were used to ensure stability of slopes, and experimental techniques were applied for their phyto-fixation; geosynthetics, rebar grids, varietal herbs, gooseberries and thuja were used. Results: for recreation of the unique structure, a special set of design, survey and construction works was developed, as well as works to maintain the structure during its exploitation. In particular, we have developed the method of detection of the recreated ditch based on the stratification of bulk soils by their age; the methods for fastening the slopes; lawn grass mixture formula for slopes with angles of 45° and 65°; drainage system. Conclusions: owing to the research work, for the first time this construction was completed with the required parameters, while the earlier recreation attempts failed due to erosion and landslide processes. The developed methods can be applied for recreation of other ancient defensive fortifications on the fields of great battles and for landscaping the territories with complex relief.