CN104831679A - Method for measuring and calculating intervals between rib sills of soft foundation energy dissipation type debris flow drainage groove and application - Google Patents

Abstract

The invention discloses a method for measuring and calculating intervals between rib sills of a soft foundation energy dissipation type debris flow drainage groove and application. According to the method for measuring and calculating the intervals between the rib sills, firstly, the longitudinal gradient of the drainage groove is determined according to measurement and calculation of a large scale topographical map or field investigation and actual measurement; then, the weight degree of debris flow is determined according to calculation of a debris flow weight degree calculation formula or actual sampling and actual measurement; finally, the intervals between the rib sills of the soft foundation energy dissipation type debris flow drainage groove are determined according to the measurement and calculation formula of the intervals between the rib sills. According to the method, the three major factors of the longitudinal gradient of the drainage groove, the weight degree of the debris flow and the buried depth of the rib sills of the drainage groove are comprehensively considered, the measurement and calculation formula of the intervals between the rib sills of the soft foundation energy dissipation type debris flow drainage groove is obtained by means of the arrangement characteristic of the rib sills of the soft foundation energy dissipation type debris flow drainage groove and data fitting performed according to an indoor simulation test result, the intervals between the rib sills under different conditions can be reasonably determined, a scientific basis is provided for designing debris flow disaster prevention and treatment engineering, and the measurement and calculation method makes calculation easy and convenient and meets the requirements of the engineering.

Description

The rib sill spacing measuring method of soft base energy dissipation type debris flow drainage groove and application

Technical field

The present invention relates to a kind of rib sill spacing measuring method of soft base energy dissipation type debris flow drainage groove, and the application when prevention and cure project middle rib sill line space design.

Background technology

Mud-rock flow is a kind of two-phase solid-liquid fluid containing mud, sand and stone between landslide and current, in motion state that is turbulent and laminar flow, have outburst suddenly, motion fast, energy is huge, impact force is strong, last the characteristic of activities such as of short duration, is the common geologic hazard type in mountain area.At present, debris flow drainage groove is the effective engineering measure of one of control mud-stone flow disaster.Prevent and reduce natural disasters in practice at long-term mud-rock flow, the form of debris flow drainage groove is formed and perfect gradually; One of debris flow drainage groove form conventional is at present soft base energy dissipation type drainage groove, this drainage groove adopts separate type retaining wall---rib sill combining structure, take full advantage of ditch bed and rib sill to the energy dissipating effect of mud-rock flow, ensure that the safety excretion of mountain torrents and mud-rock flow.

Soft base energy dissipating principle is the high degree of agitation of mud-rock flow by being full of clast and ditch bed matter, consumes the motion complementary energy of mud-rock flow, to maintain mud-rock flow Uniform Flow.The effect of rib sill keeps clast volumetric concentration in plunge pool, erosion and deposition is made to reach balance, basis is not emptied, by (after rib sill) drop growth and decline after sill, automatic adjustment mud position longitudinal river slope and flow velocity, on-way resistance and local resistance are coordinated, keeps the constant of mud-rock flow severe and the defeated power of moving.Therefore, the key factor of required consideration when reasonable Arrangement rib sill spacing is the design of soft base energy dissipating drainage groove.If drainage groove rib sill are arranged overstocked, the waste of resource will be caused; If arranged rare, ditch bed material was subject to the effect of mud-rock flow retrogressive erosion, basis, rib sill rear portion may be caused to be washed away, affect rib sill stability, and then cause rib sill to destroy, and affect the safe operation of engineering.

At present, the determination about rib sill spacing according to the rib sill line space design formula provided in " debris flow control works design specifications " (DZ/T0239-2004), can only also not have other the measuring and calculating defining method about rib sill spacing.According to " debris flow control works design specifications " (DZ/T0239-2004), rib sill spacing adopts following formula to determine:

$L=\frac{H-\mathrm{\ΔH}}{I_0-I^{\′}}$

In formula, L is erosion control floor (i.e. rib sill) spacing (m); H is erosion control floor (i.e. rib sill) buried depth (m), generally gets H=1.5 ~ 4.0m; Δ H is erosion control floor (i.e. rib sill) safe superelevation (m), generally gets Δ H=0.5m; I ₀fall (i.e. drainage groove longitudinal river slope) for drainage groove designs longitudinal gradient; I ' falls for the drainage groove longitudinal gradient after washing away under floor (i.e. rib sill), generally gets I '=(0.5 ~ 0.25) I ₀.From above-mentioned formula analysis, the size of rib sill spacing L is larger by the impact of drainage groove longitudinal river slope.With rib sill buried depth be 3.5m, safe superelevation is for 0.5m, I '=0.25I ₀for example, under different drainage groove longitudinal river slope, rib sill distance computation value is as following table 1:

Drainage groove longitudinal river slope	0.050	0.080	0.100	0.125	0.150	0.175	0.200	0.225	0.250	0.275	0.300
												Rib sill spacing (m)	80.00	53.00	40.00	32.00	26.70	22.86	20.00	17.70	16.00	14.60	13.30

Rib sill distance computation value under the different drainage groove longitudinal river slope of table 1

As shown in Table 1, when drainage groove longitudinal river slope is comparatively large, such as, when being 0.200 ~ 0.300, rib sill spacing excursion is 20.00m ~ 13.30m, conforms to engineering practice; Such as, but when drainage groove longitudinal river slope is less, when being 0.050 ~ 0.080, rib sill distance computation value excursion is 80.00m ~ 53.00m, and result of calculation is bigger than normal, do not meet with existing case history.On the other hand, this rib sill distance computation formula only considers rib sill buried depth and these two factors of drainage groove longitudinal river slope, does not consider that mud-rock flow character is to the relative influence of rib sill spacing.

Summary of the invention

Object of the present invention is exactly for the deficiencies in the prior art, a kind of rib sill spacing measuring method and application thereof of soft base energy dissipation type debris flow drainage groove are provided, the method rationally can determine soft base energy dissipating drainage groove rib sill spacing, for the design of rib sill spacing provides foundation, calculate easy, desired parameters is few, and computational solution precision is high, can adapt to actual requirement of engineering.

For achieving the above object, technical scheme of the present invention is:

The present invention proposes a kind of rib sill spacing measuring method of soft base energy dissipation type debris flow drainage groove, described soft base energy dissipation type debris flow drainage groove comprises the drainage groove side wall that some bottom lands arranged at a certain distance laterally run through type rib sill and both sides thereof, and the spacing measuring method step between rib sill is as follows:

(1) by large scale topographical map survey calculation or field investigation actual measurement, drainage groove longitudinal river slope I is determined ₀; Calculated by mud-rock flow severe design formulas or actual sampling actual measurement, determine debris flow body severe γ, unit kN/m ³.

(2) by the spacing L between following formula determination rib sill

$L=0.423\frac{e^{0.195h_0}{\mathrm{\γ}}^{0.5}}{I_0}$

In formula, the spacing between L-rib sill, unit m;

H ₀-rib sill buried depth, gets " debris flow control works design specifications " recommendation according to engineering practice, value 1.5-4.0m;

γ-debris flow body severe, unit kN/m ³, determined by step ();

I ₀-drainage groove longitudinal river slope, is determined by step ().

The inventive method is based on more than 80 debris flow drainage groove simulated experiments, and in conjunction with soft base energy dissipating drainage groove rib sill layout feature, by carrying out scale model, data fitting etc. to simulated experiment result, thus draw the design formulas of soft base energy dissipation type debris flow drainage groove rib sill spacing, be applicable to the determination of soft base energy dissipation type debris flow drainage groove rib sill spacing in engineering design.

Compared with prior art, the invention has the beneficial effects as follows: considered drainage groove longitudinal river slope, debris flow body severe, the large factor of drainage groove rib sill buried depth three, and in conjunction with soft base energy dissipation type debris flow drainage groove rib sill layout feature, carry out data fitting by simulation laboratory test result and obtain soft base energy dissipation type debris flow drainage groove rib sill spacing measure formula, rationally can determine the rib sill spacing under different situations, for disaster prevention engineering design provides scientific basis, and this measuring method calculates easy, adapt to requirement of engineering.

Accompanying drawing explanation

Fig. 1 is the longitudinal sectional view of soft base energy dissipation type debris flow drainage groove.

Fig. 2 is the schematic top plan view of soft base energy dissipation type debris flow drainage groove.

Number in the figure is as follows:

1 rib sill 2 side wall

I ₀spacing between drainage groove longitudinal river slope L rib sill

H ₀rib sill buried depth

Detailed description of the invention

Below in conjunction with accompanying drawing, the preferred embodiments of the present invention are further described.

Embodiment one

As shown in Figure 1 and Figure 2.Certain debris flow gully is a Zhigou of large Jinchuan, Upper Reaches of Dadu River master stream right bank, and drainage area is 8.5km ², the long 6.20km of tap drain, basin peak height above sea level 3650m, minimum point height above sea level 2700m, have that mountain is high, a lineament that Gu Shen, slope are steep, for the formation of mud-rock flow and activity provide favorable terrain geomorphologic conditions.

For alleviating local mud-stone flow disaster, intend building a soft base energy dissipation type debris flow drainage groove in mud-rock flow tap drain road, described soft base energy dissipation type debris flow drainage groove comprises the drainage groove side wall 2 that some bottom lands arranged at a certain distance laterally run through type rib sill 1 and both sides thereof.Calculate the spacing between these drainage groove rib sill 1 below, concrete steps are as follows:

The first step, by large scale topographical map survey calculation, determines drainage groove longitudinal river slope I ₀be 0.12; Calculated by mud-rock flow severe design formulas, determine that debris flow body severe γ is 19kN/m ³.

Second step, according to " debris flow control works design specifications ", and incorporation engineering is actual, determines rib sill 1 buried depth h ₀for 2.0m; By the spacing between following formula determination rib sill 1 $L=0.423\frac{e^{0.195h_0}{\mathrm{\γ}}^{0.5}}{I_0}=0.423\frac{e^{0.195\×2}\×{19}^{0.5}}{0.12}=22m.$ According to this can the design of this drainage groove time rib sill 1 between spacing value be 22m.

Embodiment two

As shown in Figure 1 and Figure 2.Certain debris flow gully is a Zhigou of Sun Shui river, Along The Anning River tributary right bank, the long 4.20km of tap drain, drainage area 4.10km ², flowing through certain county town, is a disastrous debris flow gully frequently.This gully mud-rock flow forming region raceway groove is suddenly anxious, two sides side slope extremely unstable, and has landslide activity, often breaks out disastrous mud-rock flow in ditch.According to engineering of blocking, then engineering quantity and investment are all quite large, and effect is very unobvious.

For alleviating local mud-stone flow disaster, intend building a soft base energy dissipation type debris flow drainage groove at mud-rock flow raceway groove accumulation area, described soft base energy dissipation type debris flow drainage groove comprises the drainage groove side wall 2 that some bottom lands arranged at a certain distance laterally run through type rib sill 1 and both sides thereof.Calculate the spacing between these drainage groove rib sill 1 below, concrete steps are as follows:

The first step, is surveyed by field investigation, determines drainage groove longitudinal river slope I ₀be 0.15; By reality sampling actual measurement, determine that debris flow body severe γ is 17kN/m ³.

Second step, according to " debris flow control works design specifications ", and incorporation engineering is actual, determines rib sill 1 buried depth h ₀for 3.0m; By the spacing between following formula determination rib sill 1 $L=0.423\frac{e^{0.195h_0}{\mathrm{\γ}}^{0.5}}{I_0}=0.423\frac{e^{0.195\×3}\×{17}^{0.5}}{0.15}=19m.$ According to this can the design of this drainage groove time rib sill 1 between spacing value be 19m.

Claims (2)

1. the rib sill spacing measuring method of a soft base energy dissipation type debris flow drainage groove, described soft base energy dissipation type debris flow drainage groove comprises the drainage groove side wall (2) that some bottom lands arranged at a certain distance laterally run through type rib sill (1) and both sides thereof, it is characterized in that: the spacing measuring method step between rib sill (1) is as follows:

(1) by large scale topographical map survey calculation or field investigation actual measurement, drainage groove longitudinal river slope I is determined ₀; Calculated by mud-rock flow severe design formulas or actual sampling actual measurement, determine debris flow body severe γ, unit kN/m ³;

(2) by the spacing L between following formula determination rib sill (1)

$L=0.423\frac{e^{0.195h_0}{\mathrm{\γ}}^{0.5}}{I_0}$

In formula, the spacing between L-rib sill (1), unit m;

H ₀-rib sill (1) buried depth, value 1.5-4.0m;

γ-debris flow body severe, unit kN/m ³, determined by step ();

I ₀-drainage groove longitudinal river slope, is determined by step ().

2. the application of soft base energy dissipation type debris flow drainage groove rib sill spacing measuring method as claimed in claim 1, is characterized in that: the determination being applicable to soft base energy dissipation type debris flow drainage groove rib sill spacing.