SU51519A1 - Method for developing trenches under water - Google Patents

Description

The slopes of the sandy soil are kept in water at a slight angle (26-28) and are rapidly washed out with flowing water; therefore, in the case of excavating a trench in the bottom of sandy soil, a trench has to be provided with very gentle slopes.

In order to keep the slopes of the sandy soil under water at a large angle and protect them temporarily from erosion, according to the proposed method, heavy w, ity from iron beams are laid on the pond dcho on the sides of the trench to be developed. The load on the slope from w, itov increases the stability of the slope, and, to eliminate the possibility of creeping themselves w, itov their upper edges bind to the pile or other anchoring means, clogged outside the prism of the collapse. Excavation is made between the shields, gradually lowering, imis on the slopes. The additional prism of the soil held by the shields above the angle of repose is determined from the condition of the balance of the shields relative to the axis of rotation passing through point O (Fig. 1), i.e. the upper edge.

In FIG. 1 shows a diagram explaining the theoretical justification of the proposed method; FIG. 2 and 3 device shields (in two mutually perpendicular cuts); FIG. 4 and 5 is a trench development scheme (cross section and top view).

Shields stacked on the sides of the intended trench to the bottom of the reservoir consist of beams connected together (Fig. 2 and 3) in groups of 5-b pieces. At the ends of the beams / there are holes for the bolts and each group of beams is connected at the ends

short transverse beams with gaskets 2 of the boards. Shields 3

placed on the bottom of the reservoir before the attack to excavate the soil for the trench, and the soil is removed from the space left between the two shields along the axis of the trench. When excavating, the shields 3 (Fig. 4) are lowered onto the formed slopes from the soil slide and cover them.

You can also lay the shields on the finished slopes when they are still not steep enough, i.e., first excavate to incomplete depth and continue further excavation between the shields along the trench axis to the required depth. The shields 3 will be lowered and

they form angles greater than the angle of repose f, and their upper edge is attached to the pile 4. After the pipe sections or tunnel w are installed in the finished trench, they 3 are lifted and used in the next section of the trench.

With the weight of the soil (sand) in the water I POOL: g and the angle of its repose J 26 °, given by the load / from the shields (Fig. 1), one can determine

angles X for different depths H from consideration of the equilibrium conditions of the shields relative to the axis of rotation kx (Fig. 1). X is proportional to

I nn load p and vice versa // /.

The results of the calculation made by the author for cases, more often by meeting; in practice, i.e. for depth from 8 to 14 m, are given in the following table below:

The subject matter of the invention.

Claims (2)

1. A method of developing trenches under water, characterized in that heavy shields are laid on the sides of the supposed trench, leading them to their own or other anchoring means, and excavating between these shields to increase the angle of slope of the trench thanks to loading shields, descending on the slopes as the excavation. 2. Acceptance of the method according to claim 1, characterized in that the soil is first excavated to an incomplete depth, and then the shields are laid on the slope of the excavation and the dredging continues between the shields to the desired trench depth. to the author's testimony A. A. Borovik No. 51519 FIG. 2 -- - -about,