CN106156516A - A kind of Urban Streets based on wind tunnel test Pedestrian Level Winds appraisal procedure - Google Patents

Abstract

A kind of Urban Streets based on wind tunnel test Pedestrian Level Winds appraisal procedure, it relates to a kind of Urban Streets Pedestrian Level Winds appraisal procedure, is specifically related to a kind of Urban Streets based on wind tunnel test Pedestrian Level Winds appraisal procedure.The present invention is to solve the problem that existing wind environment appraisal procedure precision is not enough.The parameter to the Irwin wind speed probe improved that specifically comprises the following steps that of the present invention is demarcated；With typical Urban Streets as object of study；Carry out wind environment test；Formula (2) and formula (3) is utilized to determine the hourly average wind velocity U of Urban Streets pedestrian level under each wind angle_i,siteWith gustiness U_i,gust,siteRespectively with 10m height hourly average wind velocity U_10,siteRatio r_MAnd r_G；R is compared based on wind speed_MAnd r_G, by hourly average wind speed threshold value U in wind environment evaluation criteria_thrBe converted to hourly average wind speed threshold value U that Urban Streets 10m highly locates_thr,MOr fitful wind equivalence hourly average wind speed threshold value U_thr,GEM.The invention belongs to architectural wind environment field.

Description

A kind of Urban Streets based on wind tunnel test Pedestrian Level Winds appraisal procedure

Technical field

The present invention relates to a kind of Urban Streets Pedestrian Level Winds appraisal procedure, be specifically related to a kind of city based on wind tunnel test Block, city Pedestrian Level Winds appraisal procedure, belongs to architectural wind environment field.

Background technology

Along with the development of Chinese Urbanization, (surpassing) skyscraper emerges in multitude, and layout is various, the bodily form is complicated.City In high-lager building and groups of building can significantly change wind field about so that avenue, building corner and entrance Occur that obvious wind speed accelerates in region due to " funnelling ", thus deteriorate the wind environment of pedestrian level, cause pedestrian to produce Give birth to discomfort, even cause danger.

Along with people's quality of the life and the raising of the comfortable theory of health, the quality of Urban Streets Pedestrian Level Winds obtains day by day Pay attention to.In order to avoid causing Pedestrian Level Winds uncomfortable, even dangerous because of irrational construction style and layout, need to be in block At the beginning of planning and designing, its Pedestrian Level Winds quality is correctly predicted and assesses, and the region that wind environment is second-rate is entered Row optimizes design.

Wind tunnel test is the main method of research Urban Streets Pedestrian Level Winds, be also use the earliest, the most most widely used General wind environment Forecasting Methodology.1981, Irwin invented a kind of omnirange pressure transducer (wind speed probe), and this wind speed is visited Head is under the conditions of stream field interference is less, and the Multipoint synchronous that can realize whole region pedestrian level wind speed is measured.Substantial amounts of wind Environmental test and rating test show, Irwin wind speed probe can obtain mean wind speed and the measurement result of fluctuating wind speed accurately, It is applicable to practical engineering project research.

The Pedestrian Level Winds appraisal procedure of Urban Streets mainly include wind speed than Evaluation Method, apparent wind comfort level Evaluation Method and Exceeded threshold probability assessment method etc..1) wind speed than Evaluation Method with the pedestrian level mean wind speed of Urban Streets measuring point and identical height Distant place flow the wind speed intensity of variation that the ratio of mean wind speed causes to reflect building to exist, the method can only be sentenced qualitatively The relative mass quality of the wind environment of other Urban Streets zones of different, and unrelated with the impression of people (owing to can not reflect that wind speed is exhausted To size).Owing to wind speed is than Evaluation Method simple possible, and can obtain accurate assessment result, therefore the method is For conventional method, also used by some codes and standards.2) apparent wind comfort level Evaluation Method with the comfortableness demand of people for going out Send out point, give the frequency of the uncomfortable wind of wind speed threshold value corresponding to the different behaviors of people and permission.But the method fails Consider that the impact of wind speed (meteorological data) is flowed in building location, also cannot reflect the stochastic behaviour of wind speed.3) exceeded threshold The local meteorological data of Urban Streets, with the comfortableness of people and security requirement as starting point, is united by probability assessment method simultaneously Meter is analyzed, and the pedestrian's mean wind speed calculating measuring point under full wind angle exceedes the probability of mean wind speed threshold value；Surpass by comparing measuring point More probability and maximum allowable outcross probability, assess the Pedestrian Level Winds of Urban Streets quantitatively.Exceeded threshold probability assessment method Considered the stochastic behaviour of wind speed by the method for probability, be presently the most appraisal procedure accurately.But, due to this Evaluation Method Need to combine local meteorological data, and algorithm is relative complex, causes its practical application.

Summary of the invention

The present invention solves the problem that existing wind environment appraisal procedure precision is not enough, and then propose a kind of based on wind tunnel test Urban Streets Pedestrian Level Winds appraisal procedure.

The present invention solves that the problems referred to above adopt the technical scheme that: the concrete steps of appraisal procedure of the present invention are such as Under:

Step one, the parameter of Irwin wind speed probe improved is demarcated；

Step 2, with typical Urban Streets as object of study, use acrylic board or PVC board to make with certain scaling factor Owned building and the profile of structures near this block, and improvement is set at the pedestrian level of block at a certain distance Irwin wind speed probe, thus obtain the test model of wind environment test；

Step 3, carry out wind environment test, it is thus achieved that under different parameters operating mode, the pedestrian level hour of Urban Streets model is put down All wind velocity U_iWith gustiness U_i,gust, wherein gustiness U_i,gustCan be obtained by following formula:

U_i,gust=U_i+g·σ_u (1)

In formula (1), g represents peak factor, generally takes 2.5；σ_uRepresent wind speed root-mean-square value；

Step 4, formula (2) and formula (3) is utilized to determine the hourly average wind of Urban Streets pedestrian level under each wind angle Speed U_i,siteWith gustiness U_i,gust,siteRespectively with 10m height hourly average wind velocity U_10,siteRatio r_MAnd r_G:

$r_M=\frac{U_{i,site}}{U_{10,site}}=\frac{U_i}{U_r}\×{\left(\frac{z_{ref}}{10}\right)}^{\mathrm{\α}}---\left(2\right),$

$r_G=\frac{U_{i,gust,site}}{U_{10,site}}=\frac{U_{i,gust}}{U_r}\×{\left(\frac{z_{ref}}{10}\right)}^{\mathrm{\α}}---\left(3\right),$

U in formula (2) and formula (3)_rRepresent in wind environment test and to flow mean wind speed, Z at reference altitude_refRepresent Urban Streets reference altitude, α represents the ground roughness exponent of exponential law wind profile；

Step 5, compare r based on wind speed_MAnd r_G, by hourly average wind speed threshold value U in wind environment evaluation criteria_thrBe converted to Hourly average wind speed threshold value U that Urban Streets 10m highly locates_thr,MOr fitful wind equivalence hourly average wind speed threshold value U_thr,GEM:

$U_{thr,M}=\frac{U_{thr}}{r_M}---\left(4\right)$

$U_{thr,GEM}=\frac{1.85U_{thr}}{r_G}---\left(5\right)$

In formula, U_thrIt it is the hourly average wind speed threshold value in Lawson evaluation criteria；1.85 represent gustiness U_i,gust It is equivalent to fitful wind equivalence hourly average wind velocity U_i,GEMConversion coefficient, it may be assumed that

U_i,gust=1.85U_GEM(6)；

Step 6, add up and analyze intend assessment Urban Streets local meteorological data, determine good state wind under 16 wind angles Wind direction frequency and wind speed probability distribution；Generally meteorological data includes hourly average wind speed and the average wind that 10m highly locates To；Under θ wind angle, each measuring point wind velocity U exceedes wind speed threshold value U_thr,MOr U_thr,GEMProbability be:

$P_{\mathrm{\θ}}(U>U_{thr,M})=A_{\mathrm{\θ}}\·\exp \[-{\left(\frac{U_{thr,M}}{c_{\mathrm{\θ}}}\right)}^{k_{\mathrm{\θ}}}\]---\left(7\right)$

$P_{\mathrm{\θ}}(U>U_{thr,GEM})=A_{\mathrm{\θ}}\·\exp \[-{\left(\frac{U_{thr,GEM}}{c_{\mathrm{\θ}}}\right)}^{k_{\mathrm{\θ}}}\]---\left(8\right)$

In formula (7) and formula (8), θ=1,2,3 ..., 16, represent 16 wind angle numberings conventional in meteorology, Wind angle is spaced apart 22.5 °；A_θRepresent the wind direction frequency of wind angle θ；c_θAnd k_θWhen representing wind angle θ respectively, Weibull is distributed letter The scale parameter of number and form parameter；

Under step 7, cumulative all wind angles, each measuring point wind velocity U exceedes wind speed threshold value U_thr,MOr U_thr,GEMProbability, i.e. should The outcross probability of threshold value wind speed:

$P(U>U_{thr,M})=\underset{\mathrm{\θ}=1}{\overset{16}{\Σ}}{P}_{\mathrm{\θ}}(U>U_{thr,M})---\left(9\right)$

$P(U>U_{thr,GEM})=\underset{\mathrm{\θ}=1}{\overset{16}{\Σ}}{P}_{\mathrm{\θ}}(U>U_{thr,GEM})---\left(10\right);$

Step 8, based on the outcross probability P (U > U under full wind angle_thr,M) or P (U > U_thr,GEM), and combine Lawson and comment Estimate the maximum allowable outcross probability P in standard_max, the comfortableness of assessment Urban Streets Pedestrian Level Winds and safety.

The invention has the beneficial effects as follows: 1, the present invention is by combining the aerodynamic information of Urban Streets pedestrian level, working as ground vapour As three aspects such as data and the wind environment evaluation criterias with certain fraction, comprehensive, consider different parameters work in detail The Urban Streets type of condition, different regions difference and the impact of different pedestrian activity, can realize Urban Streets Pedestrian Level Winds Accurate quantitative analysis assessment；2, the wind environment appraisal procedure of the present invention, can be that layout designs and the wind environment design of Urban Streets carries For foundation, it is to avoid produce discomfort during walk or cause danger.

Accompanying drawing explanation

Fig. 1 is Urban Streets based on wind tunnel test Pedestrian Level Winds estimation flow figure, and Fig. 2 is that Irwin wind speed probe is whole Body structural representation, Fig. 3 is Irwin wind speed probe rating test figure, and Fig. 4 is Irwin wind speed probe calibration curve schematic diagram, figure 5 is the Dalian Area wind rose whole year.

Detailed description of the invention

Detailed description of the invention one: combine Fig. 1 to Fig. 4 and present embodiment is described, a kind of based on wind-tunnel described in present embodiment Specifically comprising the following steps that of the Urban Streets Pedestrian Level Winds appraisal procedure of test

Step one, the parameter of Irwin wind speed probe improved is demarcated；

Step 2, with typical Urban Streets as object of study, use acrylic board or PVC board to make with certain scaling factor Owned building and the profile of structures near this block, and improvement is set at the pedestrian level of block at a certain distance Irwin wind speed probe, thus obtain the test model of wind environment test；

Step 3, carry out wind environment test, it is thus achieved that under different parameters operating mode, the pedestrian level hour of Urban Streets model is put down All wind velocity U_iWith gustiness U_i,gust, wherein gustiness U_i,gustCan be obtained by following formula:

U_i,gust=U_i+g·σ_u (1)

In formula (1), g represents peak factor, generally takes 2.5；σ_uRepresent wind speed root-mean-square value；

Step 4, formula (2) and formula (3) is utilized to determine the hourly average wind of Urban Streets pedestrian level under each wind angle Speed U_i,siteWith gustiness U_i,gust,siteRespectively with 10m height hourly average wind velocity U_10,siteRatio r_MAnd r_G:

$r_M=\frac{U_{i,site}}{U_{10,site}}=\frac{U_i}{U_r}\×{\left(\frac{z_{ref}}{10}\right)}^{\mathrm{\α}}---\left(2\right),$

$r_G=\frac{U_{i,gust,site}}{U_{10,site}}=\frac{U_{i,gust}}{U_r}\×{\left(\frac{z_{ref}}{10}\right)}^{\mathrm{\α}}---\left(3\right),$

U in formula (2) and formula (3)_rRepresent in wind environment test and to flow mean wind speed, Z at reference altitude_refRepresent Urban Streets reference altitude, α represents the ground roughness exponent of exponential law wind profile；

Step 5, compare r based on wind speed_MAnd r_G, by hourly average wind speed threshold value U in wind environment evaluation criteria_thrBe converted to Hourly average wind speed threshold value U that Urban Streets 10m highly locates_thrMOr fitful wind equivalence hourly average wind speed threshold value U_thrGEM:

$U_{thr,M}=\frac{U_{thr}}{r_M}---\left(4\right)$

$U_{thr,GEM}=\frac{1.85U_{thr}}{r_G}---\left(5\right)$

In formula, U_thrIt it is the hourly average wind speed threshold value in Lawson evaluation criteria；1.85 represent gustiness U_i,gust It is equivalent to fitful wind equivalence hourly average wind velocity U_i,GEMConversion coefficient, it may be assumed that

U_i,gust=1.85U_GEM(6)；

Step 6, add up and analyze intend assessment Urban Streets local meteorological data, determine good state wind under 16 wind angles Wind direction frequency and wind speed probability distribution；Generally meteorological data includes hourly average wind speed and the average wind that 10m highly locates To；Under θ wind angle, each measuring point wind velocity U exceedes wind speed threshold value U_thr,MOr U_thr,GEMProbability be:

$P_{\mathrm{\θ}}(U>U_{thr,M})=A_{\mathrm{\θ}}\·\exp \[-{\left(\frac{U_{thr,M}}{c_{\mathrm{\θ}}}\right)}^{k_{\mathrm{\θ}}}\]---\left(7\right)$

$P_{\mathrm{\θ}}(U>U_{thr,GEM})=A_{\mathrm{\θ}}\·\exp \[-{\left(\frac{U_{thr,GEM}}{c_{\mathrm{\θ}}}\right)}^{k_{\mathrm{\θ}}}\]---\left(8\right)$

In formula (7) and formula (8), θ=1,2,3 ..., 16, represent 16 wind angle numberings conventional in meteorology, Wind angle is spaced apart 22.5 °；A_θRepresent the wind direction frequency of wind angle θ；c_θAnd k_θWhen representing wind angle θ respectively, Weibull is distributed letter The scale parameter of number and form parameter；

Under step 7, cumulative all wind angles, each measuring point wind velocity U exceedes wind speed threshold value U_thr,MOr U_thr,GEMProbability, i.e. should The outcross probability of threshold value wind speed:

$P(U>U_{thr,M})=\underset{\mathrm{\θ}=1}{\overset{16}{\Σ}}{P}_{\mathrm{\θ}}(U>U_{thr,M})---\left(9\right)$

$P(U>U_{thr,GEM})=\underset{\mathrm{\θ}=1}{\overset{16}{\Σ}}{P}_{\mathrm{\θ}}(U>U_{thr,GEM})---\left(10\right);$

Step 8, based on the outcross probability P (U > U under full wind angle_thr,M) or P (U > U_thr,GEM), and combine Lawson and comment Estimate the maximum allowable outcross probability P in standard_max, the comfortableness of assessment Urban Streets Pedestrian Level Winds and safety.

The Irwin wind speed probe improved in present embodiment by an external diameter be 10mm, the cylinder of a height of 15mm, and therefrom dig Going a diameter 6mm, the small column of deep 10mm to obtain, pressure port K1 is surveyed by the hollow steel pipe of a 10mm length, 1mm external diameter The pressure p 1 on amount ground, pressure port K2 measures pedestrian level H=6.7mm by the hollow steel pipe of a 26.7mm length, 1mm external diameter The pressure at (assuming that the length scaling factor of wind environment test is 1/300, then 6.7mm is corresponding to actual pedestrian level 2m) place p2。

For the Irwin wind speed probe improved, pressure p 1, p2 are represented by with the relation of pedestrian level wind velocity U:

$U=a\sqrt{p1-p2}+b---\left(13\right)$

In formula (13), a and b is respectively wind speed probe parameter, can pass through pitot tube or the measurement result of hot-wire anemometer Demarcate.

Utilize pitot tube to measure the mean wind speed U of pedestrian level, and use least square fitting wind velocity U and pressure differentialBetween linear relationship, as shown in Figure 4.Table 2 is the fitting result of a and b.

Table 2 probe parameter calibration result

Detailed description of the invention two: combine Fig. 1 and present embodiment is described, a kind of based on wind tunnel test described in present embodiment The Irwin wind speed probe improved in the step one of Urban Streets Pedestrian Level Winds appraisal procedure is 10mm, a height of by an external diameter The cylinder of 15mm, and therefrom cut out a diameter 6mm, the small column of deep 10mm obtains.Can be by measuring the pressure p 1 on ground Pressure p 2 with at pedestrian level H=6.7mm, calculates pedestrian level wind velocity U.Other composition and annexation be embodied as Mode one is identical.

Detailed description of the invention three: combine Fig. 1 and present embodiment is described, a kind of based on wind tunnel test described in present embodiment The spacing of the Irwin wind speed probe improved in the step 2 of Urban Streets Pedestrian Level Winds appraisal procedure is not less than 40mm, to subtract Interfering of little wind speed probe stream field；And the test wind should be remained above 10m/s, to ensure the test essence of wind speed probe Degree；Model in wind tunnel can use acrylic board or PVC board to make.Other composition and annexation and detailed description of the invention one phase With.

Detailed description of the invention four: combine Fig. 1 and present embodiment is described, a kind of based on wind tunnel test described in present embodiment The hourly average of Urban Streets pedestrian level in the step 3 of Urban Streets Pedestrian Level Winds appraisal procedure, step 4, step 5 Wind velocity U_i, hourly average wind speed ratio r_MWith hourly average wind speed threshold value U_thr,MHourly average wind speed gas corresponding to Urban Streets Dynamic information；The gustiness U of Urban Streets pedestrian level_i,gust, gustiness ratio r_GWith fitful wind equivalence hourly average wind speed threshold Value U_thr,GEMFitful wind equivalence hourly average wind speed aerodynamic information corresponding to Urban Streets；Both can be used for Urban Streets pedestrian The assessment of wind environment.Other composition and annexation are identical with detailed description of the invention one.

Detailed description of the invention five: combine Fig. 1 and present embodiment is described, a kind of based on wind tunnel test described in present embodiment The parameter of Weibull distribution function under each wind angle in the step 6 of Urban Streets Pedestrian Level Winds appraisal procedure and step 7, Including wind direction frequency A_θ, scale parameter c_θWith form parameter k_θ, it is to be obtained by the meteorological data statistical analysis that place, Urban Streets is local Arrive.Other composition and annexation are identical with detailed description of the invention one.

Detailed description of the invention six: combine Fig. 1 and present embodiment is described, a kind of based on wind tunnel test described in present embodiment Hour mean wind speed threshold value U in the step 5 of Urban Streets Pedestrian Level Winds appraisal procedure and step 8_thrSurmount with maximum allowable Probability P_maxBe given by Lawson evaluation criteria.Wind environment is assessed by this wind environment evaluation criteria according to the different feeling of pedestrian It is divided into Evaluation of Comfort and risk assessment, is finely divided according to the different movable and different assessment place of pedestrian the most again, right Should be in different hourly average wind speed threshold values U_thrWith maximum allowable outcross probability P_max.Outcross probability P by relatively each measuring point (U>U_thr,M) or P (U > U_thr,GEM) and maximum allowable outcross probability P_max, it is achieved accurate to comfortableness level and risk level Qualitative assessment.Other composition and annexation are identical with detailed description of the invention one.

Embodiment:

As a example by Dalian Area in detail, the statistical analysis technique of meteorological data is described in detail.Meteorological data generally includes what 10m highly located Hourly average wind speed and mean wind direction.The statistical analysis of meteorological data wind speed and direction data is to obtain the general of good state wind wind speed Rate distribution function, is used for calculating each measuring point wind velocity U and exceedes Urban Streets wind speed threshold value U_thr,MOr U_thr,GEMProbability, thus assess The quality of Urban Streets Pedestrian Level Winds.

The two-parameter distribution of Weibull is the probability Distribution Model of a kind of universally recognized good state wind Maximum wind speed, the present invention The parameter of matching Weibull probability-distribution function is i.e. carried out by the meteorological data of Dalian Area.According in Daliang City's Meteorological Services By hourly average wind speed and direction observational data, the most effective sample at 2004, the Dalian Area that the heart provides～10m height in 2014 These 95981, statistical analysis conversion obtain the hourly average wind speed of 16 wind angles, wind direction frequency and Weibull distribution Parameter value, as shown in table 3.Accompanying drawing 5 gives the annual wind rose of Dalian Area.

Table 3 hourly average based on meteorological data wind speed and Weibull distributed constant

The wind direction frequency A that i.e. be can get in formula (7) and formula (8) under each wind angle by table 3_θ, scale parameter c_θAnd form parameter k_θ.Convolution (9) and formula (10) and Urban Streets wind speed threshold value U_thr,MOr U_thr,GEM, can be calculated under full wind angle is super More probability P (U > U_thr,M) or P (U > U_thr,GEM)；Afterwards, by comparing outcross probability P (U > U_thr,M) or P (U > U_thr,GEM) and Allow greatly outcross probability P_max, assess comfortableness and the safety of Urban Streets Pedestrian Level Winds.

The above, be only presently preferred embodiments of the present invention, and the present invention not makees any pro forma restriction, though So the present invention is disclosed above with preferred embodiment, but is not limited to the present invention, any technology people being familiar with this specialty Member, in the range of without departing from technical solution of the present invention, when the technology contents of available the disclosure above makes a little change or modification For the Equivalent embodiments of equivalent variations, as long as being without departing from technical solution of the present invention content, according to the technical spirit of the present invention, Within the spirit and principles in the present invention, any simple amendment, equivalent and the improvement etc. that above example is made, the most still Within belonging to the protection domain of technical solution of the present invention.

Claims (6)

1. Urban Streets based on a wind tunnel test Pedestrian Level Winds appraisal procedure, it is characterised in that: described one is based on wind Specifically comprising the following steps that of the Urban Streets Pedestrian Level Winds appraisal procedure of hole test

Step one, the parameter of Irwin wind speed probe improved is demarcated；

Step 2, with typical Urban Streets as object of study, use acrylic board or PVC board to make this street with certain scaling factor Owned building and the profile of structures near district, and the Irwin wind of improvement is set at the pedestrian level of block at a certain distance Speed probe, thus obtain the test model of wind environment test；

Step 3, carry out wind environment test, it is thus achieved that the pedestrian level hourly average wind of Urban Streets model under different parameters operating mode Speed U_iWith gustiness U_i,gust, wherein gustiness U_i,gustCan be obtained by following formula:

U_i,gust=U_i+g·σ_u (1)

In formula (1), g represents peak factor, generally takes 2.5；σ_uRepresent wind speed root-mean-square value；

Step 4, formula (2) and formula (3) is utilized to determine the hourly average wind speed of Urban Streets pedestrian level under each wind angle U_i,siteWith gustiness U_i,gust,siteRespectively with 10m height hourly average wind velocity U_10,siteRatio r_MAnd r_G:

$r_M=\frac{U_{i,site}}{U_{10,site}}=\frac{U_i}{U_r}\×{\left(\frac{z_{ref}}{10}\right)}^{\mathrm{\α}}---\left(2\right),$

$r_G=\frac{U_{i,gust,site}}{U_{10,site}}=\frac{U_{i,gust}}{U_r}\×{\left(\frac{z_{ref}}{10}\right)}^{\mathrm{\α}}---\left(3\right),$

U in formula (2) and formula (3)_rRepresent in wind environment test and to flow mean wind speed, Z at reference altitude_refRepresent city street District's reference altitude, α represents the ground roughness exponent of exponential law wind profile；

Step 5, compare r based on wind speed_MAnd r_G, by hourly average wind speed threshold value U in wind environment evaluation criteria_thrBe converted to city Hourly average wind speed threshold value U that block 10m highly locates_thr,MOr fitful wind equivalence hourly average wind speed threshold value U_thr,GEM:

$U_{thr,M}=\frac{U_{thr}}{r_M}---\left(4\right)$

$U_{thr,GEM}=\frac{1.85U_{thr}}{r_G}---\left(5\right)$

In formula, U_thrIt it is the hourly average wind speed threshold value in Lawson evaluation criteria；1.85 represent gustiness U_i,gustEquivalence For fitful wind equivalence hourly average wind velocity U_i,GEMConversion coefficient, it may be assumed that

U_i,gust=1.85U_GEM(6)；

Step 6, add up and analyze intend assessment Urban Streets local meteorological data, determine the wind of good state wind under 16 wind angles To frequency and wind speed probability distribution；Generally meteorological data includes hourly average wind speed and the mean wind direction that 10m highly locates；θ Under wind angle, each measuring point wind velocity U exceedes wind speed threshold value U_thr,MOr U_thr,GEMProbability be:

$P_{\mathrm{\θ}}(U>U_{thr,M})=A_{\mathrm{\θ}}\·\exp \[-{\left(\frac{U_{thr,M}}{c_{\mathrm{\θ}}}\right)}^{k_{\mathrm{\θ}}}\]---\left(7\right)$

$P_{\mathrm{\θ}}(U>U_{thr,GEM})=A_{\mathrm{\θ}}\·\exp \[-{\left(\frac{U_{thr,GEM}}{c_{\mathrm{\θ}}}\right)}^{k_{\mathrm{\θ}}}\]---\left(8\right)$

In formula (7) and formula (8), θ=1,2,3 ..., 16, represent 16 wind angle numberings conventional in meteorology, wind direction Angular spacing is 22.5 °；A_θRepresent the wind direction frequency of wind angle θ；c_θAnd k_θWeibull distribution function when representing wind angle θ respectively Scale parameter and form parameter；

Under step 7, cumulative all wind angles, each measuring point wind velocity U exceedes wind speed threshold value U_thr,MOr U_thr,GEMProbability, i.e. this threshold value The outcross probability of wind speed:

$P(U>U_{thr,M})=\underset{\mathrm{\θ}=1}{\overset{16}{\Σ}}{P}_{\mathrm{\θ}}(U>U_{thr,M})---\left(9\right)$

$P(U>U_{thr,GEM})=\underset{\mathrm{\θ}=1}{\overset{16}{\Σ}}{P}_{\mathrm{\θ}}(U>U_{thr,GEM})---\left(10\right);$

Step 8, based on the outcross probability P (U > U under full wind angle_thr,M) or P (U > U_thr,GEM), and combine Lawson assessment mark Maximum allowable outcross probability P in standard_max, the comfortableness of assessment Urban Streets Pedestrian Level Winds and safety.

A kind of Urban Streets based on wind tunnel test Pedestrian Level Winds appraisal procedure, its feature exists In: the Irwin wind speed probe improved in step one by an external diameter be 10mm, the cylinder of a height of 15mm, and therefrom cut out one straight Footpath 6mm, the small column of deep 10mm obtain.Can be by the pressure at the pressure p 1 on measurement ground and pedestrian level H=6.7mm P2, calculates pedestrian level wind velocity U.

A kind of Urban Streets based on wind tunnel test Pedestrian Level Winds appraisal procedure, its feature exists In: the spacing of the Irwin wind speed probe improved in step 2 is not less than 40mm, to reduce the most dry of wind speed probe stream field Disturb；And the test wind should be remained above 10m/s, to ensure the measuring accuracy of wind speed probe；Model in wind tunnel can use sub-gram Power plate or PVC board make.

A kind of Urban Streets based on wind tunnel test Pedestrian Level Winds appraisal procedure, its feature exists In: the hourly average wind velocity U of Urban Streets pedestrian level in step 3, step 4, step 5_i, hourly average wind speed ratio r_MWith Hourly average wind speed threshold value U_thr,MHourly average wind speed aerodynamic information corresponding to Urban Streets；The battle array of Urban Streets pedestrian level Wind wind velocity U_i,gust, gustiness ratio r_GWith fitful wind equivalence hourly average wind speed threshold value U_thr,GEMFitful wind corresponding to Urban Streets Equivalence hourly average wind speed aerodynamic information；Both can be used for the assessment of Urban Streets Pedestrian Level Winds.

A kind of Urban Streets based on wind tunnel test Pedestrian Level Winds appraisal procedure, its feature exists In: the parameter of Weibull distribution function under each wind angle in step 6 and step 7, including wind direction frequency A_θ, scale parameter c_θWith Form parameter k_θ, it is to be obtained by the meteorological data statistical analysis that place, Urban Streets is local.

A kind of Urban Streets based on wind tunnel test Pedestrian Level Winds appraisal procedure, its feature exists In: hour mean wind speed threshold value U in step 5 and step 8_thrWith maximum allowable outcross probability P_maxBy Lawson evaluation criteria Be given.Wind environment assessment is divided into Evaluation of Comfort and danger to comment according to the different feeling of pedestrian by this wind environment evaluation criteria Estimate, be finely divided, corresponding to different hourly average wind speed thresholds according to the different movable and different assessment place of pedestrian the most again Value U_thrWith maximum allowable outcross probability P_max.Outcross probability P (U > U by relatively each measuring point_thr,M) or P (U > U_thr,GEM) and Allow greatly outcross probability P_max, it is achieved the accurate quantitative analysis of comfortableness level and risk level is assessed.