CN205719803U - A kind of device measuring rock-soil material lateral pressure coefficient and Poisson's ratio - Google Patents

Abstract

The utility model discloses a kind of device measuring rock-soil material lateral pressure coefficient and Poisson's ratio, it is characterised in that: by limited support, steel loop, hydraulic bag, water check valve, limiting plate, hydralic pressure gauge, lower platen, top board, base is constituted.Forcing press applies known axial compressive force, and hydralic pressure gauge measures examination lateral deformation to pressure produced by liquid, indirectly measures the lateral pressure of rock-soil material, thus calculates lateral pressure coefficient, and then extrapolates rock-soil material Poisson's ratio.The utility model has the advantage of the Poisson's ratio that accurate can measure rock-soil material, simple and practical reliably.

Description

A kind of device measuring rock-soil material lateral pressure coefficient and Poisson's ratio

Technical field

This utility model is mainly used in measuring in rock-soil material test lateral pressure coefficient and the Poisson's ratio of rock-soil material, is one Plant novel instrumentation and testing device, and drastically increase the precision of measurement result.

Background technology

Poisson's ratio be reflection elastic properties of materials characteristic a constant, refer to material when unidirectional pressurized (or tension), radially Strain and the ratio of the absolute value of axial strain, be generally used for the numerical pressure analysis of engineering part.Conventional measuring method is By the way of adhering resistance strain sheets on sample, measure its Poisson's ratio, but the deformation range that the method is measured is limited, and Sample addition of the rigidity of sticking tablet, can cause certain error, and meanwhile soil body compression process deformation is relatively large, strain Sheet is easy to fall off, produces moderate finite deformation, it is impossible to secondary uses.The lateral pressure coefficient of this novel quick measurement rock-soil material and Poisson's ratio Device well overcomes these shortcomings, simple to operate, convenient, and error is little.

Utility model content

The technical problems to be solved in the utility model is to provide a kind of device novel, easy to measure rock-soil material Lateral pressure coefficient and Poisson's ratio, obtain preferable result with shirtsleeve operation.

For achieving the above object, this utility model can take technical scheme as follows:

A kind of device measuring rock-soil material lateral pressure coefficient and Poisson's ratio, by limited support, steel loop, hydraulic bag, sealing Valve, limiting plate, hydralic pressure gauge, lower platen, top board, base is constituted.The left and right portion of described base symmetric finite position support respectively, Described left limit support, right limit supporting structure are identical, and lower platen is installed at the middle part of described base, and the height of lower platen is slightly higher than Base, described steel loop is fixed on the limited support of left and right, and bottom level is parallel and lower platen, and described hydraulic bag is pasted at steel loop Inside, bottom connects has water filling port, described water check valve to be arranged on water filling port, controls the entrance of water；Outlet is arranged at hydraulic bag top, Connecting with conduit, the other end of conduit connects hydralic pressure gauge, and the change of hydralic pressure gauge pressure, i.e. material of rock and soil confined pressure change, described Limiting plate is arranged on the top of limited support, plays to top board a offset qualification, and described top board is connected to forcing press, Forcing press provides axial pressure to measured rock-soil material.

Theoretical principle of the present utility model is: under conditions of having confined compression rock-soil material, confined pressure σ_x=σ_y, without lateral Deformation, i.e. ε_x=ε_y=0, bring generalized Hooke law into:

${\mathrm{\ϵ}}_x=\frac{1}{E}\[{\mathrm{\σ}}_x-v({\mathrm{\σ}}_y+{\mathrm{\σ}}_z)\]$

${\mathrm{\ϵ}}_y=\frac{1}{E}\[{\mathrm{\σ}}_y-v({\mathrm{\σ}}_x+{\mathrm{\σ}}_z)\]$

That is:

σ_x-ν(σ_x+σ_z)=0

Lateral pressure coefficient can be obtainedRelation with Poisson's ratio ν:

$\mathrm{\ξ}=\frac{{\mathrm{\σ}}_x}{{\mathrm{\σ}}_z}=\frac{v}{1-v}$

That is:

$v=\frac{\mathrm{\ξ}}{1+\mathrm{\ξ}}$

According to above-mentioned theory principle, apply certain axial compressive force σ in this experiment₁, by recording liquid in hydraulic bag Pressure, namely confined pressure σ of rock-soil material₃.Make σ₃-σ₁Curve, is the side of rock-soil material at its G-bar of elastic stage Pressure coefficient, is calculating to obtain the Poisson's ratio of sample according to above-mentioned.

The beneficial effects of the utility model are: by simple experimental procedure, record the data that we need, more in addition letter Single computing, i.e. can get lateral pressure coefficient and the Poisson's ratio of the rock-soil material that we need.The theory that this experimental provision uses is former Reason is simple, and operational approach is convenient, and results of measuring is accurate.

Accompanying drawing explanation

Fig. 1 is main TV structure schematic diagram of the present utility model

Fig. 2 is plan structure schematic diagram of the present utility model

In figure: 1 increased pressure board；2 times bearing plates；3 hydraulic bags；4 steel loops；5 hydralic pressure gauges；6 water check valves；7 limited supports；8 is spacing Plate；9 tested rock-soil materials；10 bases.

Detailed description of the invention

Below in conjunction with the accompanying drawings this utility model is described in further detail:

This utility model by limited support, steel loop, hydraulic bag, water check valve, limiting plate, hydralic pressure gauge, lower platen, top board, Base, forcing press combines, and applies known axial compressive force with forcing press, and rock-soil material lateral institute pressurized measured by hydralic pressure gauge Power, thus calculate lateral pressure coefficient, and then calculate the Poisson's ratio of rock-soil material.Its version as shown in Figure 1, including It is placed on the top board 1 on tested rock-soil material 9 top, is placed on the lower platen 2 of tested rock-soil material 9 bottom, described top board 1 Being fixed on forcing press, be used for providing the pressure axial to rock-soil material, described lower platen 2 is fixed on base 10, described steel Ring 4 is fixed on limited support, and the viscous of described steel loop 4 againsts hydraulic bag 3, and the bottom of described hydraulic bag 3 arranges a water filling Mouthful, connecting and water check valve 6 is installed on the conduit of water filling port, control the entrance of water with water check valve 6, top is by conduit and hydralic pressure gauge 5 Connecting, described hydralic pressure gauge 5 is connected with limited support 7, and hydralic pressure gauge 5 can be used to measure the change of rock-soil material confined pressure.Described Left and right portion limited support is symmetrically mounted on base 10.

It is embodied as step as follows:

(1) limited support made in advance is fixed on the left and right sides of base, and lower platen is arranged on the middle part of base, Hydraulic bag is well pasted inside steel loop, then by one with being arranged on limited support, and makes bottom level and lower platen Parallel, the bottom of hydraulic bag connects water check valve by conduit, and top outlet connects hydralic pressure gauge, and is fixed on by hydralic pressure gauge spacing On support.

(2) rock-soil material sample is fabricated to standard cylindrical sample, size: highly with steel loop height, diameter compares steel Smaller 10 millimeter of ring diameter.

(3) rock-soil material sample is put in the equipment fixed, i.e. in steel loop, open water check valve, by bottom water injection mouth Water filling in hydraulic bag, until hydraulic bag is completely filled with water, discharges bubble by top outlet, closes water check valve.Now liquid Pressure table has certain force value, reads and records.

(4) opening forcing press, experiment starts, and compresses rock-soil material.Loading process is according to the loading side of correlation technique code Test specimen is pressurizeed by formula with speed, the reading of hydralic pressure gauge corresponding under record different pressures size, until rock-soil material destroys.

(5) data process: σ under different pressures in loading process₁, manometric reading deducts initial pressure, is difference Confined pressure σ corresponding under pressure₃, make σ₃-σ₁Curve, the G-bar of its first half linear stage is earth lateral pressure system Number ξ, further according to formula:

$v=\frac{\mathrm{\ξ}}{1+\mathrm{\ξ}}$

Calculate to obtain the Poisson's ratio of rock-soil material sample.

Above section is described and describes ultimate principle of the present utility model, principal character, novelty and advantage.The industry Skilled person will appreciate that, this utility model is not limited by above-mentioned enforcement example, retouches in above-mentioned enforcement example and description The simply principle of the present utility model stated, on the premise of without departing from this utility model spirit and scope, this utility model also can There are various changes and modifications, in the range of these changes and improvements both fall within claimed this utility model.This utility model is wanted Protection domain is asked to be defined by appending claims and equivalent thereof.

Claims (1)

1. the device measuring rock-soil material lateral pressure coefficient and Poisson's ratio, it is characterised in that: include top board (1), press down Plate (2), hydraulic bag (3), steel loop (4), hydralic pressure gauge (5), water check valve (6), limited support (7), limiting plate (8), base (10) structure Becoming, the left and right portion of described base (10) is symmetrically installed with the identical limited support of structure (7) respectively, and described lower platen (2) is installed At the middle part of base (10), described steel loop (4) is fixed on left and right limited support (7), and described hydraulic bag (3) is pasted at steel loop (4) internal, connect bottom it and have water filling port, described water check valve (6) to be arranged on water filling port, described hydralic pressure gauge (5) and hydraulic bag (3) being connected by conduit, hydralic pressure gauge (5) is fixed on limited support (7), and described limiting plate (8) is arranged on limited support (7) Top, top board (1) is carried out offset qualification, described top board (1) is external in forcing press.