SU876833A1 - Apparatus for determining dynamic characteristics of soil foundations - Google Patents

Description

(54) CONSTITUTION FOR DETERMINING DYNAMIC CHARACTERISTICS OF GROUND BASES

I

The invention relates to construction and is intended for field determinations of the dynamic characteristics of the soil foundations necessary for the design and calculation of the foundations of machines with dynamic loads.

Devices are known for determining the dynamic characteristics of soil foundations of foundations, including a base plate (stamp) rigidly connected to the vibrating machine 1J.

The disadvantage of these devices is that they do not provide for the creation of an explicitly pronounced force of the horizontal direction in the plane of the base plate and the accuracy of the determinations.

The closest technical solution to the present invention is a device for determining the dynamic characteristics of primer bases, including a beam with a set of weights, rigid stamps attached to the ends of the beam, a directional vibrator mounted on it with unbalanced mass. mi and measuring devices 2.

The main disadvantage of the device design is the impossibility of smoothly adjusting the intensity in the direction of dynamic action on the move, which reduces the accuracy of the definitions and limits the capabilities of the device.

The purpose of the invention is to improve the accuracy of definitions.

The goal is achieved by the fact that in a known device for determining the dynamic characteristics of soil foundations, including a beam with a set of weights, rigid punches attached to the ends of the beam, a directional vibrator mounted on it with unbalanced masses and measuring devices, the directional vibrator is equipped with a mechanism rotation relative to the beam, and the beam is connected to one of the dies by means of a ball joint, and with the other through a hinge mounted on

Claims (2)

20, sliders installed in the longitudinal grooves formed in the beam, the axis of rotation and the vibrator aligned with the intersection line of the rotation plane of the centers of unbalance masses p with a plane passing through the axis of the hinges of the sliders perpendicular to the longitudinal axis of the beam. FIG. 1 and 2 show the proposed device, the general view; in fig. 3 shows section A-A in FIG. I; in fig. 4 shows a section B-B in FIG. 3; in fig. 5 is a section BB in FIG. 1. The device includes a beam 1 with a set of weights 2, mounted on the ends of the beam of the chips 3 and 4, a vibrator 5 of directional action with unbalanced masses 6 and measuring devices 7. The beam I is connected to the die 3 by means of a bow joint 8, by clamp 4 - through 9 longitudinal slots installed in the 1 longitudinal grooves formed in the beam, 9, crawled on this stamp ,, fixed with hinges of the stamp. The directional vibrator 5 is equipped with a rotation mechanism relative to beam 1, filled, for example, as a self-locking worm gear pair, and mounted on beam 1 so that the axis of rotation of the vibrator 5 is aligned with the intersection line of the plane of rotation of the unbalance masses 6 with a brace, a hinge passing through the axis of the hinges of the sliders perpendicular to the longitudinal axis of the beam 1. I The device operates as follows. . In the process of determining the dynamic characteristics of soil foundations, the vibrator 5 of directional action in the most general case takes an inclined position relative to the beam 1 (Fig. 1). When the vibrator 5 motors are operating, its rotating unbalanced masses 6 create a harmonic force of directional action. The vertical component of this force passes through the axis of the hinges. and therefore is completely perceived by the stamp 4. The horizontal component is perceived only by the stamp 3, since the horizontal force on the stamp 4 is not transmitted through the sliders. At the same time, the stamp 4 makes only vertical, and the chip 3 makes only horizontal vibrations. In accordance with the direction of movement at the base of the stamp 4, only variable deformations of elastic uniform compression are observed, and at the base of the stamp 3 only variable deformations of elastic uniform shear of the soil are observed. If necessary, a change in the magnitude of the load on each of the dies 3 and 4 and their ratio is provided by means of a rotation mechanism by changing the vibrating angle 5 of the vibrator 5 relative to the longitudinal axis of the beam 1. When the vibrator 5 rotates, when the plane of rotation of the unbalance masses 6 changes from a vertical position to the horizontal stamp 4 and deformations of the elastic uniform compression of the soil at its base vary from 4 of its maximum value to some. the minimum value and the amplitudes of the horizontal oscillations of the stamp 3 and the deformations of the elastic shear of the soil at the base of the stamp 3 range from zero to some maximum value. By varying the number of weights 2 and moving their set along beam 1, the constancy of the resonant frequency of oscillations of the dynamic system is achieved with variations in the average pressure under the dies 3 or 4, or the constancy of the average pressure and the variations of the resonant frequency of oscillations. Measuring devices 7, associated with dies 4 and 3, work out signals proportional to the kinematic parameters of the corresponding chips. These signals are recorded and serve as the initial data for determining the dynamic characteristics of the base, respectively, for elastic uniform compression and for elastic uniform shear of the soil. The determination of the dynamic characteristics of the soil bases is carried out according to any of the known methods. When determining the nonlinearity of the dynamic characteristics of the soil bases associated with the variability of the kinematic parameters of the oscillations, the possibility of a smooth controlled change in the harmonic load on the chips over wide limits becomes especially important. The use of the proposed device in determining the dynamic characteristics of soil foundations makes it possible to increase their reliability and, consequently, reduce the damage to foundations of machines with dynamic loads, increase their reliability, reduce the cost of repairing them, and reduce subsidence deformations of soil foundations. An apparatus for determining the dynamic characteristics of soil foundations, including a beam with a set of weights, rigid punches attached to the ends of the beam, a directional vibrator mounted on it with unbalance masses and measuring devices, characterized in that, in order to increase the accuracy of determinations, a directional vibrator the action is provided with a turning mechanism relative to the beam, and the beam is connected to one of the schtamp by means of a bow joint, and with the other through hinge-mounted as it slides installed in the beam formed in the longitudinal grooves prnchem axis of rotation of the vibrator is aligned with the line peresechegsh plane of rotation of the unbalanced mass centers to the plane. the beam passing through the axis of the hinges of the sliders is pendicular to the longitudinal axis. Sources of information taken into account in the examination of 8768336 per-1, Copyright of the USSR If 608072.1 class, About 01 M 7/00, 1977. 2. USSR author's certificate IT 6901 IS, cl. E 02 D 1 / pO, 1978 (prototype). .-four vg FIG. 3 in FIG. FIG. five bb