Safety evaluation of road alignment based on energy conservation law
-
摘要: 为了评价平纵线形对山区高等级公路安全性的影响, 根据能量守恒原理, 分析了汽车在下坡路段行驶过程中, 纵坡坡度、纵坡坡长及平曲线半径对汽车制动系统温度升高的影响。以某山区高速公路下坡路段为例, 研究了公路线形与事故发生率的关系。分析结果表明: 汽车稳定车速行驶的临界坡度会随传动比和车速的升高而增大; 公路的安全性会随平均纵坡坡度和坡长乘积的增加而降低; 较小的平曲线半径将有利于提高汽车发动机辅助制动的效能, 有利于公路安全性的提高; 较大的平曲线半径方差将会增加汽车行车制动器的使用频率, 降低公路的安全性。Abstract: In order to estimate the influences of horizontal and vertical alignments on the safety of high classified highway in mountain area, based on energy conservation law, the influences of longitudinal gradient, gradient length and horizontal curve radius on the temperature rise of brake system were analyzed when vehicle ran downhill.Taking example for a downhill section in mountain area, the relationship between highway alignments and accident rates was validated.Analysis result indicates that when vehicle runs stably the critical gradient increases with the increases of transmission ratio and vehicle speed.Highway safety decreases with the increase of the product between average gradient and gradient length.Because the lesser curve radius can enhance the ability of engine brake, highway safety is improved.The larger mean square error of curve radius may increase the use frequency of vehicle brake, therefore, highway safety will be reduced.
-
Key words:
- traffic safety /
- road alignment /
- energy conservation law /
- safety evaluation
-
表 1 线形参数
Table 1. Parameters of road aligmments
序号 起始桩号 长度 半径 纵坡 序号 起始桩号 长度 半径 纵坡 序号 起始桩号 长度 半径 纵坡 序号 起始桩号 长度 半径 纵坡 1 K25+652 603 -862 -0.8 22 K30+370 592 -600 -5.5 43 K35+480 314 2 000 -3.0 64 K41+970 320 -927 3.0 2 K26+255 205 ∞ -3.0 23 K30+962 88 ∞ -5.5 44 K35+794 484 ∞ -3.0 65 K42+290 389 432 6.0 3 K26+460 250 480 -3.0 24 K31+050 87 ∞ -3.0 45 K36+278 262 650 -3.0 66 K42+679 121 -485 6.0 4 K26+710 266 480 -0.6 25 K31+137 123 749 -5.5 46 K36+540 439 650 2.0 67 K42+800 212 -485 3.0 5 K26+976 134 ∞ -0.6 26 K31+260 295 749 -5.8 47 K36+979 231 ∞ 2.0 68 K43+010 158 -485 6.0 6 K27+110 229 ∞ -1.9 27 K31+555 355 -583 -5.8 48 K37+210 470 ∞ -3.8 69 K43+168 303 432 6.0 7 K27+339 171 -430 -1.9 28 K31+910 117 -583 -3.0 49 K37+680 527 ∞ -1.0 70 K43+471 139 -344 6.0 8 K27+510 525 -430 -5.8 29 K32+027 183 572 -5.5 50 K38+207 293 -620 -1.0 71 K438+610 180 -344 3.0 9 K28+035 115 ∞ -5.8 30 K32+210 312 572 -5.5 51 K38+500 370 -620 5.0 72 K438+790 172 -344 6.0 10 K28+150 91 ∞ -3.0 31 K32+522 216 ∞ -5.5 52 K38+870 362 -620 -0.3 73 K43+962 136 ∞ 6.0 11 K28+241 109 430 -3.0 32 K32+738 132 -555 -5.5 53 K39+232 168 ∞ -0.3 74 K44+098 292 409 6.0 12 K28+350 241 430 -5.0 33 K32+870 150 -555 -3.0 54 K39+400 300 ∞ -3.6 75 K44+390 130 409 3.0 13 K28+591 269 -751 -5.0 34 K33+020 234 -555 -6.0 55 K39+700 237 ∞ 2.8 76 K44+520 160 -399 3.0 14 K28+860 140 430 -5.0 35 K33+254 366 ∞ -6.0 56 K39+937 663 800 2.8 77 K44+680 210 -399 5.2 15 K29+000 365 430 -2.6 36 K33+620 150 ∞ -3.0 57 K40+600 343 800 5.6 78 K44+890 294 286 5.2 16 K29+365 175 -500 -2.6 37 K33+770 420 ∞ -6.0 58 K40+943 121 ∞ 5.6 79 K45+184 156 -463 5.2 17 K29+540 114 -500 -5.5 38 K34+190 180 500 -6.0 59 K41+064 136 -400 5.6 80 K45+340 322 -463 2.5 18 K29+654 820 820 -5.5 39 K34+370 319 500 -2.9 60 K41+200 170 -400 3.0 81 K45+662 338 494 2.5 19 K28+855 315 ∞ -3.0 40 K34+689 81 ∞ -2.9 61 K41+370 202 -400 6.0 82 K46+000 190 494 -4.0 20 K30+170 102 ∞ -3.0 41 K34+770 612 ∞ -4.8 62 K41+572 312 366 6.0 83 K46+190 158 ∞ -4.0 21 K30+272 98 -600 -3.0 42 K35+382 98 2 000 -4.8 63 K41+884 86 -927 6.0 84 K46+348 212 -310 -4.0 注: 路段长度及弯道半径的单位为m; 纵坡坡度单位为%, 坡度上坡为正, 下坡为负; 平曲线半径左弯为正, 右弯为负。 表 2 公路线形和事故统计
Table 2. Statistics of road alignments and accidents
路段 ∑ijsj/(10-2 m) σR/m σv/(km·h-1) 死亡事故/起 一般事故/起 K39+937~K46+000 4.36 27 645.48 663.47 503.84 58.78 4.49 0 11 K36+979~K26+710 4.21 45 559.41 1 196.38 858.51 64.70 6.97 22 52 -
[1] HASSAN Y, EASA S M. Effect of vertical alignment ondriver perception of horizontal curves[J]. Journal of Trans-portation Engineering, 2003, 129(4): 399-407. doi: 10.1061/(ASCE)0733-947X(2003)129:4(399) [2] 李铁洪, 吴华金. 长直线接小半径曲线公路交通事故成因及预防对策[J]. 中国公路学报, 2007, 20(1): 35-40. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGGL200701006.htmLI Tie-hong, WU Hua-jin. Causes and countermeasures ofhighway traffic accidents in long straight line combined withsharp curve[J]. China Journal of Highway and Transport, 2007, 20(1): 35-40. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-ZGGL200701006.htm [3] 黄进, 方守恩. 平曲线路段事故数目与线形元素的关系[J]. 公路, 2002(2): 76-79. https://www.cnki.com.cn/Article/CJFDTOTAL-GLGL200212026.htmHUANGJin, FANGShou-en. Relationship between accidentnumber and alignment elements of horizontal curve sections[J]. Highway, 2002(2): 76-79. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-GLGL200212026.htm [4] 余强, 陈荫三, 马建, 等. 客车发动机制动下坡能力[J]. 长安大学学报: 自然科学版, 2003, 23(2): 95-97. https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200302027.htmYU Qiang, CHEN Yin-san, MA Jian, et al. Ability of busengine-braking at downhill[J]. Journal of Chang an University: Natural Science Edition, 2003, 23(2): 95-97. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200302027.htm [5] 王秀平. 高速公路线形连续性分析与评价[J]. 公路, 2009(5): 245-248. https://www.cnki.com.cn/Article/CJFDTOTAL-GLGL200905048.htmWANG Xiu-ping. Analysis and evaluation of expresswayalignment consistency[J]. Highway, 2009(5): 245-248. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-GLGL200905048.htm [6] PARK YJ, SACCOMANNO F F. Evaluating speed consistencybetween successive elements of a two-lane rural highway[J]. Transportation Research Part A, 2006, 40(5): 375-385. [7] 余强. 汽车下坡持续制动性能研究[D]. 西安: 长安大学, 2000.YU Qiang. Study on downhill continuous braking perform-ance of automobile[D]. Xi an: Chang an University, 2000. (in Chinese) -