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1.苏联近年来沥青混凝土路面的大量破坏,不可能全都归罪于现行的柔性路面设计理论的不完善。 2.路面大量破坏的主要原因总结有如下列: a.设计者机械地应用设计理论,没有充分地考虑当地的自然条件及筑路材料的性质,特别是那些颗粒组成极不一律的砾料方面; 6.设计者常企图尽可能降低修筑路面的费用,而昧然采用一些计算参数的最大值,如土与地方筑路材料(像性质不一致的砾料)的形变模量; B.某些计算参数值过高,例如在苏联道路科学研究院拟定的“柔性路面设计须知”中,关于砾料的形变模量,即未曾考虑砾料中小于0.5公厘的细土粒的含量; r.对许用于修建沥青混凝土路面基层的那些材料的形变模量,未曾提出明确的要求;关于路面结构问题,在上述的“须知”中,亦完全未加反映,而这一方面在应用当地的、大部分性质都不一致的筑路材料中,却有极重要的意义; 3.调查许多有高级路面的破坏路段,证实许多筑路单位所使用的地方材料的品质,并未符合要求。他们使用了污染的砾料,其中小于2公厘的颗粒含量大于25％,小于0.074公厘的大于10％,而这些都超过了允许的限度。此外,应用地方材料修建路面基层,在材料的一致性和密实度方面,亦均不符合要求; 4.国立全苏道路科学研究院在1956年修正的“须知”中,已将上述几项缺点加以消除。在此新“须知”中,并附载有设计与施工单位直接测定土与筑路材料形变模量的方法指示,这样,也就可能充实足够的、能说明土与筑路材料在各种不同自然情况中的强度的实际资料; 5.在新“须知”中并指出了应以什么方向来修正柔性路面设计理论,尤其是在确定行车震动对于路面、特别是土的强度的影响方面。此外,对于在天然含水量超过90％(对塑性下限而言)的过湿土壤上设计路面,亦需要作出一更新的完善的计算理论。按照行车的重现率(特别是重型车辆)的安全系数值,以及参照路面厚度的临界挠度等等亦均极需加以确定。在这一方面,理论的研究必须分别结合各种不同自然条件中所发生现象本身的物理实质而进行。
1. The massive destruction of asphalt pavement in the Soviet Union in recent years can not all be blamed on the imperfection of the current flexible pavement design theory. 2. The main reasons for the extensive destruction of pavement are summarized as follows: a. Designers apply the theory of mechanics mechanically and do not fully consider the local natural conditions and the nature of pavement materials, especially the gravel with extremely unopposed particles; 6. Designers often attempt to minimize the cost of building pavements by ignoring the maximum of some calculated parameters such as the modulus of deformation of earth-road materials (like gravel that are not of the same nature); B. Some calculations Parameter values are too high, for example, in the “Guidelines for Flexible Pavement Design” prepared by the Soviet Road Science Institute, regarding the modulus of deformation of gravel, ie, the content of fine grained soil less than 0.5 mm in gravel has not been considered; There is no explicit requirement on the modulus of deformation of those materials used for the construction of the base course of asphalt concrete pavement. As for the problem of pavement structure, the above “Notice” is not reflected at all. On the one hand, in the application of local, Most road construction materials that are inconsistent in nature are of great importance. 3. Investigation of many damaged sections of high-grade pavement confirms that the quality of local materials used by many road construction units does not meet the requirements of . They used contaminated gravel, with> 25% of the particles less than 2 mm and> 10% less than 0.074 mm, all of which exceeded the allowable limits. In addition, the use of local materials to build the pavement base also did not meet the requirements in terms of material consistency and compactness. 4. In the “Instructions” amended by the National Institute of Roads and Sciences in 1956, the above mentioned shortcomings Eliminate. In this new “Notice”, and accompanied by design and construction unit direct determination of soil and road building materials deformation modulus method of instruction, so that it may be sufficient enough to explain the earth and road materials in a variety of different nature 5. In the new “Instructions”, and pointed out in what direction should be revised to the theory of flexible pavement design, especially in determining the impact of road traffic on the road, especially the strength of the soil. In addition, designing pavements on wet soils with a natural moisture content of more than 90% (for the lower plastic limit) also requires a more complete and updated computational theory. According to the driving rate of reproduction (especially heavy vehicles) safety factor values, as well as the reference road surface thickness of the critical deflection and so on also need to be determined. In this respect, the study of the theory must be carried out in combination with the physical substance of the phenomena occurring in various natural conditions, respectively.